Sponge Remote mobile client application

1. Introduction

The Sponge Remote is a Flutter mobile application that provides a generic GUI to call remote Sponge actions. It can be run on both Android and iOS. It could be used as the one app to rule them all for Sponge services that publish actions via the Sponge REST API. All business logic has to be placed in Sponge actions, so the only requirement to have the application working is to create your own Sponge service by writing a knowledge base that define actions that will be visible and ready to run in the application or to connect to an existing Sponge service.

The application is currently under development and is not officially published. It will be released as an open source.

The Sponge Remote is especially useful when data and functionality are more important than visual aspects of a GUI, e.g. for prototyping, rapid application development, low cost solutions, etc. The reason is that the application provides only a generic and opinionated GUI whose customization is limited.

Figure 1. The mobile application architecture

One of many use cases of the application is to connect to IoT devices that have Sponge installed and execute available actions. Different types of such devices provide different sets of actions that are specific to a device features. For example one device could have a camera and provide an action to take a picture. Another device could have a temperature sensor and provide its readings or have a machine learning model and provide predictions.

The Sponge Remote uses several Sponge concepts such as actions and action arguments metadata, data types metadata, action and data type features, annotated values, provided action arguments, categories and events. It supports a convention over configuration paradigm.

You could build a customized GUI using your own Flutter code that will call the same Sponge actions as the Sponge Remote, using the upcoming Sponge Flutter API library.

The Sponge Flutter API library is currently under development and is not officially published. It will be released as an open source.

2. Functionalities

The following chapters show the key functionalities of the mobile application.

Figure 2. The navigation drawer

The navigation drawer allows switching between the main screens.

2.2. Connections

Figure 3. Selecting a connection to the Sponge instance in the action list screen

You may configure many connections to Sponge REST API services. The application allows you to connect to a single service at the same time.

Figure 4. List of connections to Sponge instances

You may add, edit and remove connections to Sponge instances as well as activate a connection. To remove a connection swipe the corresponding element.

Figure 5. Editing a connection to a Sponge instance

A Sponge address is the URL of the Sponge instance.

The application can find nearby (i.e. located on the local network) Sponge services.

2.3. Action list

Figure 6. The action list

The main screen shows the list of actions defined in the connected Sponge engine. Only actions that have argument and result metadata are available. This is because the application uses a generic access to the actions utilizing their data types, labels, descriptions, features and so on. The number in the action icon is the number of action arguments.

To call an action or set action attributes tap the triangular icon on the right side of the action label.

The floating button allows to refresh the action list from the server. The refresh button clears all entered action arguments and received results.

The application currently doesn’t supports all Sponge data types.

2.4. Action call

When an action call screen is displayed, provided arguments will be fetched from the server.

An action call screen can be closed by swiping right.

Figure 7. The action call that manages the Raspberry Pi LCD display

Actions may have read only, provided arguments to show data from the server (see the Current LCD text attribute). The REFRESH button retrieves the current values of such arguments manually.

The definition of the action that manages the Raspberry Pi LCD display

class ManageLcd(Action):
    def onConfigure(self):
        self.withLabel("Manage the LCD text and color")
        self.withDescription("Provides management of the LCD properties (display text and color). A null value doesn't change an LCD property.")
        self.withArgs([
            StringType("currentText").withMaxLength(256).withNullable(True).withFeatures({"maxLines":2})
                .withLabel("Current LCD text").withDescription("The currently displayed LCD text.").withProvided(ProvidedMeta().withValue().withReadOnly()),
            StringType("text").withMaxLength(256).withNullable(True).withFeatures({"maxLines":2})
                .withLabel("Text to display").withDescription("The text that will be displayed in the LCD.").withProvided(ProvidedMeta().withValue()),
            StringType("color").withMaxLength(6).withNullable(True).withFeatures({"characteristic":"color"})
                .withLabel("LCD color").withDescription("The LCD color.").withProvided(ProvidedMeta().withValue().withOverwrite()),
            BooleanType("clearText").withNullable(True).withDefaultValue(False)
                .withLabel("Clear text").withDescription("The text the LCD will be cleared.")
        ]).withNoResult()
        self.withFeature("icon", "monitor")
    def onCall(self, currentText, text, color, clearText = None):
        sponge.call("SetLcd", [text, color, clearText])
    def onProvideArgs(self, context):
        grovePiDevice = sponge.getVariable("grovePiDevice")
        if "currentText" in context.provide:
            context.provided["currentText"] = ProvidedValue().withValue(grovePiDevice.getLcdText())
        if "text" in context.provide:
            context.provided["text"] = ProvidedValue().withValue(grovePiDevice.getLcdText())
        if "color" in context.provide:
            context.provided["color"] = ProvidedValue().withValue(grovePiDevice.getLcdColor())

class SetLcd(Action):
    def onCall(self, text, color, clearText = None):
        sponge.getVariable("grovePiDevice").setLcd("" if (clearText or text is None) else text, color)

Figure 8. The action call that manages the Grove Pi sensors and actuators

The action call screen allows editing the action arguments.

The definition of the action that manages the Grove Pi sensors and actuators

class ManageSensorActuatorValues(Action):
    def onConfigure(self):
        self.withLabel("Manage the sensor and actuator values").withDescription("Provides management of the sensor and actuator values.")
        self.withArgs([
            NumberType("temperatureSensor").withNullable().withLabel(u"Temperature sensor (°C)").withProvided(ProvidedMeta().withValue().withReadOnly()),
            NumberType("humiditySensor").withNullable().withLabel(u"Humidity sensor (%)").withProvided(ProvidedMeta().withValue().withReadOnly()),
            NumberType("lightSensor").withNullable().withLabel(u"Light sensor").withProvided(ProvidedMeta().withValue().withReadOnly()),
            NumberType("rotarySensor").withNullable().withLabel(u"Rotary sensor").withProvided(ProvidedMeta().withValue().withReadOnly()),
            NumberType("soundSensor").withNullable().withLabel(u"Sound sensor").withProvided(ProvidedMeta().withValue().withReadOnly()),
            BooleanType("redLed").withLabel("Red LED").withProvided(ProvidedMeta().withValue().withOverwrite()),
            IntegerType("blueLed").withMinValue(0).withMaxValue(255).withLabel("Blue LED").withProvided(ProvidedMeta().withValue().withOverwrite()),
            BooleanType("buzzer").withLabel("Buzzer").withProvided(ProvidedMeta().withValue().withOverwrite())
        ]).withNoResult()
        self.withFeature("icon", "thermometer")
    def onCall(self, temperatureSensor, humiditySensor, lightSensor, rotarySensor, soundSensor, redLed, blueLed, buzzer):
        grovePiDevice = sponge.getVariable("grovePiDevice")
        grovePiDevice.setRedLed(redLed)
        grovePiDevice.setBlueLed(blueLed)
        grovePiDevice.setBuzzer(buzzer)
    def onProvideArgs(self, context):
        values = sponge.call("GetSensorActuatorValues", [context.provide])
        for name, value in values.iteritems():
            context.provided[name] = ProvidedValue().withValue(value)

class GetSensorActuatorValues(Action):
    def onCall(self, names):
        values = {}
        grovePiDevice = sponge.getVariable("grovePiDevice")
        if "temperatureSensor" or "humiditySensor" in names:
            th = grovePiDevice.getTemperatureHumiditySensor()
            if "temperatureSensor" in names:
                values["temperatureSensor"] = th.temperature if th else None
            if "humiditySensor" in names:
                values["humiditySensor"] = th.humidity if th else None
        if "lightSensor" in names:
            values["lightSensor"] = grovePiDevice.getLightSensor()
        if "rotarySensor" in names:
            values["rotarySensor"] = grovePiDevice.getRotarySensor().factor
        if "soundSensor" in names:
            values["soundSensor"] = grovePiDevice.getSoundSensor()
        if "redLed" in names:
            values["redLed"] = grovePiDevice.getRedLed()
        if "blueLed" in names:
            values["blueLed"] = grovePiDevice.getBlueLed()
        if "buzzer" in names:
            values["buzzer"] = grovePiDevice.getBuzzer()
        return values

Figure 9. The action call that sends an SMS from the Raspberry Pi

Actions arguments may be edited in multiline text fields.

The definition of the action that sends an SMS from the Raspberry Pi

class SendSms(Action):
    def onConfigure(self):
        self.withLabel("Send an SMS").withDescription("Sends a new SMS.")
        self.withArgs([
            StringType("recipient").withFormat("phone").withLabel("Recipient").withDescription("The SMS recipient."),
            StringType("message").withMaxLength(160).withFeatures({"maxLines":5}).withLabel("Message").withDescription("The SMS message.")
        ]).withNoResult()
        self.withFeature("icon", "cellphone-text")
    def onCall(self, recipient, message):
        gsm.sendSms(recipient, message)

Figure 10. The action call argument editor for a color type

The color picker widget allows a user to choose a color as an argument value.

The definition of the action that takes a color argument

class ChooseColor(Action):
    def onConfigure(self):
        self.withLabel("Choose a color").withDescription("Shows a color argument.")
        self.withArg(
            StringType("color").withMaxLength(6).withNullable(True).withFeatures({"characteristic":"color"})
                .withLabel("Color").withDescription("The color.")
        ).withResult(StringType()).withFeatures({"icon":"format-color-fill", "showClear":True})
    def onCall(self, color):
        return ("The chosen color is " + color) if color else "No color chosen"

Figure 11. The action call argument editor for a digit drawing

The drawing panel allows a user to paint an image that will be set as an argument value in an action call.

The definition of the action that recognizes a handwritten digit

class DigitsPredict(Action):
    def onConfigure(self):
        self.withLabel("Recognize a digit").withDescription("Recognizes a handwritten digit")
        self.withArg(createImageType("image")).withResult(IntegerType().withLabel("Recognized digit"))
        self.withFeature("icon", "brain")
    def onCall(self, image):
        predictions = py4j.facade.predict(image)
        prediction = max(predictions, key=predictions.get)
        probability = predictions[prediction]

        # Handle the optional predictionThreshold Sponge variable.
        predictionThreshold = sponge.getVariable("predictionThreshold", None)
        if predictionThreshold and probability < float(predictionThreshold):
            self.logger.debug("The prediction {} probability {} is lower than the threshold {}.", prediction, probability, predictionThreshold)
            return None
        else:
            self.logger.debug("Prediction: {}, probability: {}", prediction, probability)
            return int(prediction)

def imageClassifierServiceInit(py4jPlugin):
    SpongeUtils.awaitUntil(lambda: py4jPlugin.facade.isReady())

Figure 12. The action call for an attribute of type drawing

The action call screen shows all action arguments.

Figure 13. The action call result for a digit recognition

If the action has been called, the result is shown below the action label. If the result can’t be fully shown in the action list, you may tap the result to see the details.

Figure 14. The action call argument editor for a doodle drawing

Drawing panels can be configured in a corresponding action definition, where a color, a background color etc. could be specified.

The definitions of actions that represent drawing and viewing a doodle

from java.lang import System
from os import listdir
from os.path import isfile, join, isdir

class DrawAndUploadDoodle(Action):
    def onConfigure(self):
        self.withLabel("Draw and upload a doodle").withDescription("Shows a canvas to draw a doodle and uploads it to the server")
        self.withArg(
              BinaryType("image").withLabel("Doodle").withMimeType("image/png")
                     .withFeatures({"characteristic":"drawing", "width":300, "height":250, "background":"FFFFFF", "color":"000000", "strokeWidth":2})
        )
        self.withResult(StringType().withLabel("Status"))
        self.withFeatures({"icon":"brush"})
    def onCall(self, image):
        if not sponge.getVariable("demo.readOnly", False):
            filename = str(System.currentTimeMillis()) + ".png"
            SpongeUtils.writeByteArrayToFile(image, sponge.getProperty("doodlesDir") + "/" + filename)
            return "Uploaded as " + filename
        else:
            return "Uploading disabled in the read only mode"

class ListDoodles(Action):
    def onConfigure(self):
        self.withLabel("List doodles").withDescription("Returns a list of doodle filenames").withFeatures({"visible":False})
        self.withNoArgs().withResult(ListType(StringType()).withLabel("Doodles"))
    def onCall(self):
        dir = sponge.getProperty("doodlesDir")
        doodles = [f for f in listdir(dir) if isfile(join(dir, f)) and f.endswith(".png")] if isdir(dir) else []
        return sorted(doodles, reverse=True)

class ViewDoodle(Action):
    def onConfigure(self):
        self.withLabel("View a doodle").withDescription("Views a doodle")
        self.withArg(StringType("image").withLabel("Doodle name").withProvided(ProvidedMeta().withValue().withValueSet().withOverwrite()))
        self.withResult(BinaryType().withAnnotated().withMimeType("image/png").withLabel("Doodle image"))
        self.withFeature("icon", "drawing")
    def onCall(self, name):
        return AnnotatedValue(SpongeUtils.readFileToByteArray(sponge.getProperty("doodlesDir") + "/" + name)).withFeatures({"filename":"doodle_" + name})
    def onProvideArgs(self, context):
        if "image" in context.provide:
            doodles = sponge.call("ListDoodles")
            context.provided["image"] = ProvidedValue().withValue(doodles[0] if doodles else None).withValueSet(doodles)

def onStartup():
    sponge.logger.info(str(sponge.call("ListDoodles")))

Figure 15. The action call for a doodle drawing as an argument

The action call screen shows all action arguments, for example a drawing.

Figure 16. The action call that shows argument dependencies

Action arguments may depend on each other. Argument dependencies are supported in the action call panel and allow creating simple, interactive forms where some arguments are provided by the server, some entered by the user, some read only and some depend on the values of others. The important thing is that all that configuration is defined in an action in a knowledge base placed on the server side, not in the mobile application.

The definition of the action that provides arguments with dependencies

class DependingArgumentsAction(Action):
    def onConfigure(self):
        self.withLabel("Action with depending arguments")
        self.withArgs([
            StringType("continent").withLabel("Continent").withProvided(ProvidedMeta().withValueSet()),
            StringType("country").withLabel("Country").withProvided(ProvidedMeta().withValueSet().withDependency("continent")),
            StringType("city").withLabel("City").withProvided(ProvidedMeta().withValueSet().withDependency("country")),
            StringType("river").withLabel("River").withProvided(ProvidedMeta().withValueSet().withDependency("continent")),
            StringType("weather").withLabel("Weather").withProvided(ProvidedMeta().withValueSet())
        ]).withResult(StringType().withLabel("Sentences"))
        self.withFeatures({"icon":"flag", "showClear":True, "showCancel":True})
    def onCall(self, continent, country, city, river, weather):
        return "There is a city {} in {} in {}. The river {} flows in {}. It's {}.".format(city, country, continent, river, continent, weather.lower())
    def onProvideArgs(self, context):
        if "continent" in context.provide:
            context.provided["continent"] = ProvidedValue().withValueSet(["Africa", "Asia", "Europe"])
        if "country" in context.provide:
            continent = context.current["continent"]
            if continent == "Africa":
                countries = ["Nigeria", "Ethiopia", "Egypt"]
            elif continent == "Asia":
                countries = ["China", "India", "Indonesia"]
            elif continent == "Europe":
                countries = ["Russia", "Germany", "Turkey"]
            else:
                countries = []
            context.provided["country"] = ProvidedValue().withValueSet(countries)
        if "city" in context.provide:
            country = context.current["country"]
            if country == "Nigeria":
                cities = ["Lagos", "Kano", "Ibadan"]
            elif country == "Ethiopia":
                cities = ["Addis Ababa", "Gondar", "Mek'ele"]
            elif country == "Egypt":
                cities = ["Cairo", "Alexandria", "Giza"]
            elif country == "China":
                cities = ["Guangzhou", "Shanghai", "Chongqing"]
            elif country == "India":
                cities = ["Mumbai", "Delhi", "Bangalore"]
            elif country == "Indonesia":
                cities = ["Jakarta", "Surabaya", "Medan"]
            elif country == "Russia":
                cities = ["Moscow", "Saint Petersburg", "Novosibirsk"]
            elif country == "Germany":
                cities = ["Berlin", "Hamburg", "Munich"]
            elif country == "Turkey":
                cities = ["Istanbul", "Ankara", "Izmir"]
            else:
                cities = []
            context.provided["city"] = ProvidedValue().withValueSet(cities)
        if "river" in context.provide:
            continent = context.current["continent"]
            if continent == "Africa":
                rivers = ["Nile", "Chambeshi", "Niger"]
            elif continent == "Asia":
                rivers = ["Yangtze", "Yellow River", "Mekong"]
            elif continent == "Europe":
                rivers = ["Volga", "Danube", "Dnepr"]
            else:
                rivers = []
            context.provided["river"] = ProvidedValue().withValueSet(rivers)
        if "weather" in context.provide:
            context.provided["weather"] = ProvidedValue().withValueSet(["Sunny", "Cloudy", "Raining", "Snowing"])

Figure 17. The action call that shows argument dependencies and value sets

Allowed argument values can be defined in an action and provided from the server every time the action call screen is shown or an argument dependency value changes.

2.5. Action result

Figure 18. The action binary result

Actions may return contents that can be viewed for example as a HTML or a PDF file using the mobile OS viewers.

The definitions of the actions that return a HTML and a PDF file respectively

class HtmlFileOutput(Action):
    def onConfigure(self):
        self.withLabel("HTML file output").withDescription("Returns the HTML file.")
        self.withNoArgs().withResult(BinaryType().withMimeType("text/html").withLabel("HTML file"))
        self.withFeatures({"icon":"web"})
    def onCall(self):
        return String("""
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
    <head>
      <title>HTML page</title>
    </head>
    <body>
        <!-- Main content -->
        <h1>Header</h1>
        <p>Some text
    </body>
</html>
""").getBytes("UTF-8")

class PdfFileOutput(Action):
    def onConfigure(self):
        self.withLabel("PDF file output").withDescription("Returns the PDF file.")
        self.withNoArgs().withResult(BinaryType().withMimeType("application/pdf").withLabel("PDF file"))
        self.withFeatures({"icon":"file-pdf"})
    def onCall(self):
        return sponge.process(ProcessConfiguration.builder("curl", "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf")
                              .outputAsBinary()).run().outputBinary

Figure 19. The action console formatted result

Actions may return a console output, for example the result of running the df -h command on the server.

The definitions of the actions that returns OS commands output

from org.openksavi.sponge.util.process import ProcessConfiguration

class OsGetDiskSpaceInfo(Action):
    def onConfigure(self):
        self.withLabel("Get disk space info").withDescription("Returns the disk space info.")
        self.withNoArgs().withResult(StringType().withFormat("console").withLabel("Disk space info"))
        self.withFeature("icon", "console")
    def onCall(self):
        return sponge.process(ProcessConfiguration.builder("df", "-h").outputAsString()).run().outputString

class OsDmesg(Action):
    def onConfigure(self):
        self.withLabel("Run dmesg").withDescription("Returns the dmesg output.")
        self.withNoArgs().withResult(StringType().withFormat("console").withLabel("The dmesg output"))
        self.withFeature("icon", "console")
    def onCall(self):
        return sponge.process(ProcessConfiguration.builder("dmesg").outputAsString()).run().outputString

Figure 20. The action Markdown formatted result

Actions may return a Markdown formatted text.

2.6. Events

The Sponge Remote can subscribe to Sponge events. The subscription uses a Sponge gRPC service published on a default port (i.e. the REST API port plus 1). A user must have priviliges to subscribe to events and to send events.

There are a few places where Sponge events are directly used in the application:

An event list screen (handles events subscribed globally for the application).
An action call screen for actions that have refresh events configured (handles events subscribed locally for an action).

Figure 21. Event related actions

2.6.1. Event subscription

Events can be subscribed globally for the application. Subscription management is performed by a subscription action, i.e. an action that has the intent feature set to subscription. Sponge provides a default subscription action GrpcApiManageSubscription.

In case of a new event an operating system notification will be displayed.

Figure 22. Event subscription management

2.6.2. Event list

The event list screen shows all events the application has subscribed for but only those that has been sent when the application is running.

By tapping on an event the user will be directed to a screen presenting an action associated with this event. This action is called an event handler action and is set up in the event type definition as a feature handlerAction. The action is required to have an ObjectType argument with object class RemoteEvent. An event instance will be passed to that argument. After the action is called, the event is automatically dismissed from the GUI.

If there is no event handler action defined for a specific event type, a default event handler action will be shown. The default action is searched by its intent feature which has to be defaultEventHandler. Sponge provides a default event handler action GrpcApiViewEvent.

Figure 23. Event list

Event type with a default event handler action

from java.util.concurrent.atomic import AtomicLong
from org.openksavi.sponge.restapi.model import RemoteEvent

def onInit():
    sponge.setVariable("notificationNo", AtomicLong(1))

def onBeforeLoad():
    sponge.addType("Person", lambda: RecordType().withFields([
        StringType("firstName").withLabel("First name"),
        StringType("surname").withLabel("Surname")
    ]).withLabel("Person"))

    sponge.addEventType("notification", RecordType().withFields([
        StringType("source").withLabel("Source"),
        IntegerType("severity").withLabel("Severity").withNullable(),
        sponge.getType("Person", "person").withNullable()
    ]).withLabel("Notification").withFeatures({"icon":"alarm-light"}))

class NotificationSender(Trigger):
    def onConfigure(self):
        self.withEvent("notificationSender")
    def onRun(self, event):
        notificationNo = sponge.getVariable("notificationNo").getAndIncrement()
        eventNo = str(notificationNo)

        sponge.event("notification").set({"source":"Sponge", "severity":10, "person":{"firstName":"James", "surname":"Joyce"}}).label(
            "The notification " + eventNo).description("The new event " + eventNo + " notification").feature(
                "icon", IconInfo("alarm-light").withColor("FF0000" if (notificationNo % 2) == 0 else "00FF00")
            ).send()

def onStartup():
    sponge.event("notificationSender").sendEvery(Duration.ofSeconds(10))

Figure 24. Default event handler action

Event type with a custom event handler action

from org.openksavi.sponge.restapi.model import RemoteEvent

def onBeforeLoad():
    sponge.addEventType("memo", RecordType().withFields([
        StringType("message").withLabel("Message"),
    ]).withLabel("Memo").withFeatures({"handlerAction":"ViewMemoEvent", "icon":"note-text-outline"}))

class ViewMemoEvent(Action):
    def onConfigure(self):
        self.withLabel("Memo").withDescription("Shows the memo event.")
        self.withArgs([
            ObjectType("event", RemoteEvent).withFeature("visible", False),
            StringType("uppercaseMessage").withLabel("Upper case message").withProvided(
                    ProvidedMeta().withValue().withReadOnly().withDependency("event")),
        ])
        self.withNoResult()
        self.withFeatures({"visible":False, "callLabel":"Dismiss", "cancelLabel":"Close"})
    def onCall(self, event, uppercaseMessage):
        pass
    def onProvideArgs(self, context):
        if "uppercaseMessage" in context.provide:
            message = context.current["event"].attributes["message"]
            context.provided["uppercaseMessage"] = ProvidedValue().withValue(message.upper() if message else "NO MESSAGE")

Figure 25. Custom event handler action

2.6.3. Action with refresh events

Every action can have refresh events configured. When such an action is shown in the GUI, the application will subscribe to refresh events. When such event arrives, the action arguments will be automatically refreshed. Event arguments are ignored.

Action with refresh events

class ViewCounter(Action):
    def onConfigure(self):
        self.withLabel("Counter").withDescription("Shows the counter.")
        self.withArgs([
            NumberType("counter").withLabel("Counter").withProvided(ProvidedMeta().withValue().withReadOnly()),
        ]).withCallable(False)
        # This action when open in a GUI will subscribe to counterNotification events. When such event arrives, the action arguments
        # will be automatically refreshed, so the counter argument will be read from the variable and provided to a GUI.
        self.withFeatures({"cancelLabel":"Close", "refreshEvents":["counterNotification"]})
    def onProvideArgs(self, context):
        if "counter" in context.provide:
            context.provided["counter"] = ProvidedValue().withValue(sponge.getVariable("counter").get())

Figure 26. Action with refresh events

2.6.4. Sending events

Events can be sent by the application using an action. Sponge provides a default, generic action for sending events GrpcApiSendEvent.

Figure 27. Action that sends events

3. Advanced use cases

3.1. Context actions

Context actions can be specified for actions, record arguments and list elements (see the list-details) to provide related, customized sub-actions. Context actions should be specified as the contextActions feature statically for a type or an action or dynamically for an annotated value. The latter option takes precedence.

Figure 28. The action with context actions

The definition of the action with context actions

class ActionWithContextActions(Action):
    def onConfigure(self):
        self.withLabel("Action with context actions").withArgs([
            StringType("arg1").withLabel("Argument 1"),
            StringType("arg2").withLabel("Argument 2")
        ]).withNoResult().withFeature("contextActions", [
            "ActionWithContextActionsContextAction1", "ActionWithContextActionsContextAction2(arg2)", "ActionWithContextActionsContextAction3(arg2=arg2)",
            "ActionWithContextActionsContextAction4(arg1)", "ActionWithContextActionsContextAction5", "ActionWithContextActionsContextAction6",
            "MarkdownText()"
        ])
        self.withFeature("icon", "attachment")
    def onCall(self, arg1, arg2):
        pass

class ActionWithContextActionsContextAction1(Action):
    def onConfigure(self):
        self.withLabel("Context action 1").withArgs([
            RecordType("arg").withFields([
                StringType("arg1").withLabel("Argument 1"),
                StringType("arg2").withLabel("Argument 2")
            ]).withFeature("visible", False)
        ]).withResult(StringType())
        self.withFeatures({"visible":False, "icon":"tortoise"})
    def onCall(self, arg):
        return arg["arg1"]

class ActionWithContextActionsContextAction2(Action):
    def onConfigure(self):
        self.withLabel("Context action 2").withArgs([
            StringType("arg").withLabel("Argument"),
            StringType("additionalText").withLabel("Additional text"),
        ]).withResult(StringType())
        self.withFeatures({"visible":False, "icon":"tortoise"})
    def onCall(self, arg, additionalText):
        return arg + " " + additionalText

class ActionWithContextActionsContextAction3(Action):
    def onConfigure(self):
        self.withLabel("Context action 3").withArgs([
            StringType("arg1").withLabel("Argument 1"),
            StringType("arg2").withLabel("Argument 2"),
            StringType("additionalText").withLabel("Additional text"),
        ]).withResult(StringType())
        self.withFeatures({"visible":False, "icon":"tortoise"})
    def onCall(self, arg1, arg2, additionalText):
        return arg1 + " " + arg2 + " " + additionalText

class ActionWithContextActionsContextAction4(Action):
    def onConfigure(self):
        self.withLabel("Context action 4").withArgs([
            StringType("arg1NotVisible").withLabel("Argument 1 not visible").withFeatures({"visible":False}),
            StringType("arg2").withLabel("Argument 2"),
        ]).withResult(StringType())
        self.withFeatures({"visible":False, "icon":"tortoise"})
    def onCall(self, arg1NotVisible, arg2):
        return arg1NotVisible + " " + arg2

class ActionWithContextActionsContextAction5(Action):
    def onConfigure(self):
        self.withLabel("Context action 5").withArgs([
            RecordType("arg").withFields([
                StringType("arg1").withLabel("Argument 1"),
                StringType("arg2").withLabel("Argument 2")
            ]).withFeatures({"visible":False}),
            StringType("additionalText").withLabel("Additional text")
        ]).withResult(StringType())
        self.withFeatures({"visible":False, "icon":"tortoise"})
    def onCall(self, arg, additionalText):
        return arg["arg1"] + " " + additionalText

class ActionWithContextActionsContextAction6(Action):
    def onConfigure(self):
        self.withLabel("Context action 6").withArgs([
            RecordType("arg").withFields([
                StringType("arg1").withLabel("Argument 1"),
                StringType("arg2").withLabel("Argument 2")
            ])
        ]).withNoResult()
        self.withFeatures({"visible":False, "icon":"tortoise"})
    def onCall(self, arg):
        pass

3.1.1. Arguments substitution

Modes of passing arguments to a context action:

Default (e.g. "ContextAction"). In case of a context action for an action, all action arguments as a record (represented as a map) will be passed as the first argument of the context action. In case of a record argument or a list element, the record or the list element value will be passed as the first argument respectively.
Explicit substitution (format "ContextAction(targetArgName=sourceArgName,…)", e.g. "ContextAction(contextArg1=arg1,contextArg2=arg2)"). In case of a context action for an action, the argument contextArg1 of the context action will be set to a value of the argument arg1 of the parent action and the argument contextArg2 of the context action will be set to a value of the argument arg2.
Implicit substitution (format "ContextAction(sourceArgName,…)", e.g. "ContextAction(arg1)"). In case of a context action for an action, the first argument of the context action will be set to a value of the argument arg1 of the parent action.
No arguments passed (e.g. "ContextAction()").

The target argument must have the same type as the source value.

A source argument name could be a path if a source value is a record, e.g. "ContextAction(contextArg1=arg1.field1)". The this keyword can be used as the source argument name. In case of a context action for an action it is a record of all parent action arguments. In case of a record argument or a list element it is the value itself.

If a context action has any visible arguments, a new action call screen will be shown. If a context value is an annotated value, the screen will show a header containing a label of the annotated value.

The context actions feature is not propagated to sub-actions in an annotated value feature.

Context actions can use globally saved (in a mobile application) action arguments but only if there is no argument substitutions (i.e. there are no arguments passed from the main action). It is necessary to avoid inconsistency.

3.1.2. Result substitution

A context action result can be assigned to a main action argument by using the notation "parentArgName=ContextAction()". As a parent argument name you can use the this keyword which means all action arguments or all record value or a list element.

For list elements only the this keyword as a result substitution is supported.

If a context action returns null and the result substitution is this, the result will be ignored.

3.1.3. Active or inactive context actions

Before showing a list of context actions the application checks (by connecting to the server) if the context actions are active. Inactive actions will be greyed out.

3.2. List-details

Figure 29. The list-details action in the action list

Figure 30. The list-details main action screen

Figure 31. The CRUD and context actions

action form list details subaction create

Figure 32. The create/add sub-action

Figure 33. The read/view sub-action

action form list details subaction update

Figure 34. The update/modify sub-action

action form list details subaction delete

Figure 35. The delete/remove sub-action

action form list details subaction context binary

Figure 36. The context action returning a binary result

action form list details subaction context args

Figure 37. The context action with an additional argument

action form list details subaction context args result

Figure 38. The result of the context action with an additional argument

The definitions of actions implementing the list-details

from org.openksavi.sponge.util.process import ProcessConfiguration

def createBookRecordType(name):
    """ Creates a book record type.
    """
    return RecordType(name).withFields([
        IntegerType("id").withLabel("ID").withNullable().withFeature("visible", False),
        StringType("author").withLabel("Author"),
        StringType("title").withLabel("Title")
])

class RecordLibraryForm(Action):
    def onConfigure(self):
        self.withLabel("Library (books as records)")
        self.withArgs([
            StringType("search").withNullable().withLabel("Search").withFeature("responsive", True),
            StringType("order").withLabel("Sort by").withProvided(ProvidedMeta().withValue().withValueSet()),
            ListType("books").withLabel("Books").withFeatures({
                    "createAction":"RecordCreateBook", "readAction":"RecordReadBook", "updateAction":"RecordUpdateBook", "deleteAction":"RecordDeleteBook",
                    "refreshable":True,
                # Provided with overwrite to allow GUI refresh.
                }).withProvided(ProvidedMeta().withValue().withOverwrite().withDependencies(["search", "order"])).withElement(
                        createBookRecordType("book").withAnnotated()
                )
        ]).withCallable(False).withFeature("icon", "library")
    def onProvideArgs(self, context):
        global LIBRARY
        if "order" in context.provide:
            context.provided["order"] = ProvidedValue().withValue("author").withAnnotatedValueSet([
                AnnotatedValue("author").withValueLabel("Author"), AnnotatedValue("title").withValueLabel("Title")])
        if "books" in context.provide:
            context.provided["books"] = ProvidedValue().withValue(
                # Context actions are provided dynamically in an annotated value.
                map(lambda book: AnnotatedValue(book.toMap()).withValueLabel("{} - {}".format(book.author, book.title)).withFeature("contextActions", [
                        "RecordBookContextBinaryResult", "RecordBookContextNoResult", "RecordBookContextAdditionalArgs"]),
                    sorted(LIBRARY.findBooks(context.current["search"]), key = lambda book: book.author.lower() if context.current["order"] == "author" else book.title.lower())))

class RecordCreateBook(Action):
    def onConfigure(self):
        self.withLabel("Add a new book")
        self.withArg(
            createBookRecordType("book").withLabel("Book").withProvided(ProvidedMeta().withValue()).withFields([
                # Overwrite the author field.
                StringType("author").withLabel("Author").withProvided(ProvidedMeta().withValueSet(ValueSetMeta().withNotLimited())),
            ])
        ).withNoResult()
        self.withFeatures({"visible":False, "callLabel":"Save", "cancelLabel":"Cancel", "icon":"plus-box"})

    def onCall(self, book):
        global LIBRARY
        LIBRARY.addBook(book["author"], book["title"])

    def onProvideArgs(self, context):
        global LIBRARY
        if "book" in context.provide:
            # Create an initial, blank instance of a book and provide it to GUI.
            context.provided["book"] = ProvidedValue().withValue({})
        if "book.author" in context.provide:
            context.provided["book.author"] = ProvidedValue().withValueSet(LIBRARY.getAuthors())

class RecordReadBook(Action):
    def onConfigure(self):
        self.withLabel("View the book")
        # Must set withOverwrite to replace with the current value.
        self.withArg(createBookRecordType("book").withAnnotated().withLabel("Book").withProvided(
            ProvidedMeta().withValue().withOverwrite().withDependency("book.id").withReadOnly()))
        self.withCallable(False).withFeatures({"visible":False, "cancelLabel":"Close", "icon":"book-open"})
    def onProvideArgs(self, context):
        global LIBRARY
        if "book" in context.provide:
            context.provided["book"] = ProvidedValue().withValue(AnnotatedValue(LIBRARY.getBook(context.current["book.id"]).toMap()))

class RecordUpdateBook(Action):
    def onConfigure(self):
        self.withLabel("Modify the book")
        self.withArg(
            # Must set withOverwrite to replace with the current value.
            createBookRecordType("book").withAnnotated().withLabel("Book").withProvided(
                    ProvidedMeta().withValue().withOverwrite().withDependency("book.id")).withFields([
                StringType("author").withLabel("Author").withProvided(ProvidedMeta().withValueSet(ValueSetMeta().withNotLimited())),
            ])
        ).withNoResult()
        self.withFeatures({"visible":False, "callLabel":"Save", "cancelLabel":"Cancel", "icon":"square-edit-outline"})
    def onCall(self, book):
        global LIBRARY
        LIBRARY.updateBook(book.value["id"], book.value["author"], book.value["title"])
    def onProvideArgs(self, context):
        global LIBRARY
        if "book" in context.provide:
            context.provided["book"] = ProvidedValue().withValue(AnnotatedValue(LIBRARY.getBook(context.current["book.id"]).toMap()))
        if "book.author" in context.provide:
            context.provided["book.author"] = ProvidedValue().withValueSet(LIBRARY.getAuthors())

class RecordDeleteBook(Action):
    def onConfigure(self):
        self.withLabel("Remove the book")
        self.withArg(createBookRecordType("book").withAnnotated().withFeature("visible", False)).withNoResult()
        self.withFeatures({"visible":False, "callLabel":"Save", "cancelLabel":"Cancel", "icon":"delete", "confirmation":True})

    def onCall(self, book):
        global LIBRARY
        self.logger.info("Deleting book id: {}", book.value["id"])
        LIBRARY.removeBook(book.value["id"])

class RecordBookContextBinaryResult(Action):
    def onConfigure(self):
        self.withLabel("Text sample as PDF")
        self.withArg(
            createBookRecordType("book").withAnnotated().withFeature("visible", False)
        ).withResult(BinaryType().withAnnotated().withMimeType("application/pdf").withLabel("PDF"))
        self.withFeatures({"visible":False, "icon":"file-pdf"})
    def onCall(self, book):
        return AnnotatedValue(sponge.process(ProcessConfiguration.builder("curl", "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf")
                              .outputAsBinary()).run().outputBinary)

class RecordBookContextNoResult(Action):
    def onConfigure(self):
        self.withLabel("Return the book")
        self.withArg(
            createBookRecordType("book").withAnnotated().withFeature("visible", False)
        ).withNoResult().withFeatures({"visible":False, "icon":"arrow-left-bold"})
    def onCall(self, book):
        pass

class RecordBookContextAdditionalArgs(Action):
    def onConfigure(self):
        self.withLabel("Add book comment")
        self.withArgs([
            createBookRecordType("book").withAnnotated().withFeature("visible", False),
            StringType("comment").withLabel("Comment").withFeatures({"multiline":True, "maxLines":2})
        ]).withResult(StringType().withLabel("Added comment"))
        self.withFeatures({"visible":False, "icon":"comment-outline"})
    def onCall(self, book, message):
        return message

The main action should have a list argument that is provided with the overwrite option. The action shouldn’t be callable. The list argument type can be annotated and the provided list elements may have labels (AnnotatedValue().withLabel()) and descriptions. The list argument may have the following features: createAction, readAction, updateAction, deleteAction. Their values are the sub-action names that will be called to perform the CRUD operations.

There are two types of sub-actions: CRUD actions and context actions. CRUD actions implement create, read, update and delete operations. Context actions implement customized operations related to a list element.

The CRUD actions should not be visible in the actions list so they should have the visible feature set to False.

In the default scenario read, update and delete actions should have the first argument corresponding to the value of the list element. In most cases the argument visible feature should be set to False to hide it. Its type should be the same as the list element’s type. The value of the list element will be passed as this argument. In the case of a create action, no argument corresponding to any list element is necessary.

The result of a create, an update and a delete action is ignored and should be set to withNoResult.

After calling a CRUD action the main action arguments are refreshed.

3.3. Interactive form

An interactive form provides live update in a GUI and an instant modifications of a server state. It can be implemented by an action with provided and submittable arguments and action refresh events. Interactive forms can be used for example to manage IoT devices.

The following example shows a very simple MPD player implemented as a Sponge action. A change in an MPD server state generates a Sponge event. Such event is subscribed by the action in the mobile application and causes the action to refresh its arguments. On the other hand, a change made by a user in the GUI will cause such argument to be submitted to the server.

Interactive form example

import os

class MpdPlayer(Action):
    def onConfigure(self):
        self.withLabel("Player").withDescription("The MPD player.")
        self.withArgs([
            StringType("song").withLabel("Song").withNullable().withFeatures({"multiline":True, "maxLines":2}).withProvided(
                ProvidedMeta().withValue().withReadOnly()),
            StringType("album").withLabel("Album").withNullable().withFeatures({"multiline":True, "maxLines":2}).withProvided(
                ProvidedMeta().withValue().withReadOnly()),
            StringType("date").withLabel("Date").withNullable().withProvided(
                ProvidedMeta().withValue().withReadOnly()),
            IntegerType("position").withLabel("Position").withNullable().withAnnotated().withMinValue(0).withMaxValue(100).withFeatures(
                {"widget":"slider", "group":"position"}).withProvided(
                ProvidedMeta().withValue().withOverwrite().withSubmittable()),
            StringType("time").withLabel("Time").withNullable().withFeatures({"group":"position"}).withProvided(
                ProvidedMeta().withValue().withReadOnly()),
            IntegerType("volume").withLabel("Volume").withAnnotated().withMinValue(0).withMaxValue(100).withFeatures({"widget":"slider"}).withProvided(
                ProvidedMeta().withValue().withOverwrite().withSubmittable().withLazyUpdate()),
            VoidType("prev").withLabel("Previous").withAnnotated().withFeatures({"icon":"skip-previous", "group":"navigation"}).withProvided(
                ProvidedMeta().withValue().withOverwrite().withSubmittable()),
            BooleanType("play").withLabel("Play").withAnnotated().withFeatures({"group":"navigation"}).withProvided(
                ProvidedMeta().withValue().withOverwrite().withSubmittable().withLazyUpdate()),
            VoidType("next").withLabel("Next").withAnnotated().withFeatures({"icon":"skip-next", "group":"navigation"}).withProvided(
                ProvidedMeta().withValue().withOverwrite().withSubmittable())
        ]).withCallable(False).withActivatable()
        self.withFeatures({"cancelLabel":"Close", "refreshEvents":["statusPolling", "mpdNotification_.*"], "icon":"music", "contextActions":[
            "MpdPlaylist()", "MpdFindAndAddToPlaylist()", "ViewSongInfo()", "ViewSongLyrics()", "MpdLibrary()", "ViewMpdStatus()",
        ]})

    def onIsActive(self, context):
        return sponge.getVariable("mpc").isConnected()

    def __ensureStatus(self, mpc, status):
        return status if mpc.isStatusOk(status) else mpc.getStatus()

    def onProvideArgs(self, context):
        mpc = sponge.getVariable("mpc")
        status = None
        (position, size) = (None, None)

        mpc.lock.lock()
        try:
            try:
                if "position" in context.submit:
                    if context.current["position"]:
                        status = mpc.seekByPercentage(context.current["position"].value)
                if "volume" in context.submit:
                        status = mpc.setVolume(context.current["volume"].value)
                if "play" in context.submit:
                    status = mpc.togglePlay(context.current["play"].value)
                if "prev" in context.submit:
                    status = mpc.prev()
                if "next" in context.submit:
                    status = mpc.next()
            except:
                sponge.logger.warn("Submit error", sys.exc_info()[1])

            currentSong = None
            if "song" in context.provide or "date" in context.provide:
                currentSong = mpc.getCurrentSong()
            if "song" in context.provide:
                context.provided["song"] = ProvidedValue().withValue(mpc.getSongLabel(currentSong) if currentSong else None)
            if "album" in context.provide:
                context.provided["album"] = ProvidedValue().withValue(currentSong["album"] if currentSong else None)
            if "date" in context.provide:
                context.provided["date"] = ProvidedValue().withValue(currentSong["date"] if currentSong else None)
            if "position" in context.provide or "context" in context.submit:
                status = self.__ensureStatus(mpc, status)
                context.provided["position"] = ProvidedValue().withValue(AnnotatedValue(mpc.getPositionByPercentage(status)).withFeature(
                    "enabled", mpc.isStatusPlayingOrPaused(status)))
            if "time" in context.provide:
                status = self.__ensureStatus(mpc, status)
                context.provided["time"] = ProvidedValue().withValue(mpc.getTimeStatus(status))
            # Provide an annotated volume value at once if submitted.
            if "volume" in context.provide or "volume" in context.submit:
                status = self.__ensureStatus(mpc, status)
                volume = mpc.getVolume(status)
                context.provided["volume"] = ProvidedValue().withValue(AnnotatedValue(volume).withTypeLabel(
                    "Volume" + ((" (" + str(volume) + "%)") if volume else "")))
            if "play" in context.provide:
                status = self.__ensureStatus(mpc, status)
                playing = mpc.getPlay(status)
                context.provided["play"] = ProvidedValue().withValue(AnnotatedValue(playing).withFeature("icon", "pause" if playing else "play"))

            if "prev" in context.provide or "next" in context.provide:
                status = self.__ensureStatus(mpc, status)
                (position, size) = mpc.getCurrentPlaylistPositionAndSize(status)
            if "prev" in context.provide:
                context.provided["prev"] = ProvidedValue().withValue(AnnotatedValue(None).withFeature("enabled", position is not None))
            if "next" in context.provide:
                context.provided["next"] = ProvidedValue().withValue(AnnotatedValue(None).withFeature("enabled",
                        position is not None and size is not None))
        finally:
            mpc.lock.unlock()

Figure 39. The MPD player action

Figure 40. The context actions

3.4. Geographical map

ListType elements can be shown on a geographical map if its list type has the geoMap feature configured.

Each list element that has the geoPosition feature will be displayed on the map. You can tap on an icon that represents an element to see the element label and its context actions.

If an action has only one argument which is a list with a geo map and the action has no buttons, the map will be displayed in a full action call screen. If a list with a geo map is an argument in an action that doesn’t meet that criteria, the action call screen will display only a button for this argument. If the button is tapped a map screen will be shown.

If a list element has the geoLayerName feature that corresponds to a configured marker layer name, it will be assigned to that layer. If there is no marker layer configured, a default one with the null name will be created.

The map functionality is experimental.

Geographical map example

class ActionWithGeoMap(Action):
    def onConfigure(self):
        self.withLabel("Action with a geo map")
        self.withArgs([
            ListType("locations").withLabel("Locations").withAnnotated().withFeatures({
                    "geoMap":GeoMap().withCenter(GeoPosition(50.06143, 19.93658)).withZoom(15).withLayers([
                        # Use the same "group" feature to allow only one basemap to be visible at the same time.

                        # See the OpenStreetMap Tile Usage Policy at https://operations.osmfoundation.org/policies/tiles/
                        GeoTileLayer().withUrlTemplate("https://tile.openstreetmap.org/{z}/{x}/{y}.png").withLabel("OpenStreetMap")
                            .withFeatures({"visible":True, "attribution":u"© OpenStreetMap contributors", "group":"basemap"}),
                        # See the Google Maps Terms of Service at https://cloud.google.com/maps-platform/terms
                        GeoTileLayer().withUrlTemplate("https://mt0.google.com/vt/lyrs=y&hl=en&x={x}&y={y}&z={z}").withLabel("Google Hybrid")
                            .withFeatures({"visible":False, "attribution":u"Imagery ©2020 CNES/Airbus, MGGP Aero, Maxar Technologies, Map data ©2020 Google",
                                           "group":"basemap", "opacity":0.9}),

                        GeoMarkerLayer("buildings").withLabel("Buildings").withFeature("icon", IconInfo("home").withSize(50)),
                        GeoMarkerLayer("persons").withLabel("Persons")
                    ]).withFeatures({"color":"FFFFFF"})
                }).withProvided(
                    ProvidedMeta().withValue().withOverwrite()
                ).withElement(
                    StringType("location").withAnnotated()
                )
        ]).withCallable(False).withFeatures({"icon":"map"})

    def onProvideArgs(self, context):
        if "locations" in context.provide:
            locations = [
                AnnotatedValue("building1").withValueLabel("Building (with actions)").withValueDescription("Description of building 1").withFeatures({
                    "geoPosition":GeoPosition(50.06043, 19.93558), "icon":IconInfo("home").withColor("FF0000").withSize(50),
                    "geoLayerName":"buildings"}).withFeature(
                        "contextActions", ["ActionWithGeoMapViewLocation"]),
                AnnotatedValue("building2").withValueLabel("Building (without actions)").withValueDescription("Description of building 2").withFeatures({
                    "geoPosition":GeoPosition(50.06253, 19.93768),
                    "geoLayerName":"buildings"}),
                AnnotatedValue("person1").withValueLabel("Person 1 (without actions)").withValueDescription("Description of person 1").withFeatures({
                    "geoPosition":GeoPosition(50.06143, 19.93658), "icon":IconInfo("face").withColor("000000").withSize(30),
                    "geoLayerName":"persons"}),
                AnnotatedValue("person2").withValueLabel("Person 2 (without actions)").withValueDescription("Description of person 2").withFeatures({
                    "geoPosition":GeoPosition(50.06353, 19.93868), "icon":IconInfo("face").withColor("0000FF").withSize(30),
                    "geoLayerName":"persons"})
            ]
            context.provided["locations"] = ProvidedValue().withValue(AnnotatedValue(locations))

class ActionWithGeoMapViewLocation(Action):
    def onConfigure(self):
        self.withLabel("View the location")
        # Must set withOverwrite to replace with the current value.
        self.withArgs([
            StringType("location").withAnnotated().withLabel("Location").withFeature("visible", False),
            NumberType("label").withLabel("Label").withProvided(
                ProvidedMeta().withValue().withOverwrite().withReadOnly().withDependency("location")),
            NumberType("description").withLabel("Description").withProvided(
                ProvidedMeta().withValue().withOverwrite().withReadOnly().withDependency("location")),
            NumberType("latitude").withLabel("Latitude").withProvided(
                ProvidedMeta().withValue().withOverwrite().withReadOnly().withDependency("location")),
            NumberType("longitude").withLabel("Longitude").withProvided(
                ProvidedMeta().withValue().withOverwrite().withReadOnly().withDependency("location")),
            ])
        self.withCallable(False).withFeatures({"visible":False, "cancelLabel":"Close", "icon":"map-marker"})
    def onProvideArgs(self, context):
        if "label" in context.provide:
            context.provided["label"] = ProvidedValue().withValue(context.current["location"].valueLabel)
        if "description" in context.provide:
            context.provided["description"] = ProvidedValue().withValue(context.current["location"].valueDescription)
        if "latitude" in context.provide:
            context.provided["latitude"] = ProvidedValue().withValue(context.current["location"].features["geoPosition"].latitude)
        if "longitude" in context.provide:
            context.provided["longitude"] = ProvidedValue().withValue(context.current["location"].features["geoPosition"].longitude)

Figure 41. The map overview

Figure 42. The main map menu

Figure 43. The map with expanded clusters

Figure 44. The map with element badges

Figure 45. The element context actions menu

Figure 46. The element context action call

3.5. Choose dialog

A choose dialog can be used to pick a value and pass it as a result to a parent action argument.

Choose dialog example

def createFruitWithColorRecordType(name = None):
    return RecordType(name).withLabel("Fruit").withAnnotated().withFields([
                StringType("name").withLabel("Name"),
                StringType("color").withLabel("Color")
            ])

class FruitsWithColorsContextSetter(Action):
    def onConfigure(self):
        self.withLabel("Fruits with colors - context setter").withArgs([
            ListType("fruits").withLabel("Fruits").withElement(createFruitWithColorRecordType("fruit")).withDefaultValue([
                AnnotatedValue({"name":"Orange", "color":"orange"}),
                AnnotatedValue({"name":"Lemon", "color":"yellow"}),
                AnnotatedValue({"name":"Apple", "color":"red"})]).withFeatures({
                    "updateAction":"this=FruitsWithColorsContextSetter_Update(this)", "contextActions":["this=FruitsWithColorsContextSetter_Choose"]})
        ]).withCallable(False)

class FruitsWithColorsContextSetter_Update(Action):
    def onConfigure(self):
        self.withLabel("Update a fruit").withArgs([
            createFruitWithColorRecordType("fruit")
        ]).withResult(createFruitWithColorRecordType("fruit"))
        self.withFeatures({"callLabel":"Save", "visible":False})
    def onCall(self, fruit):
        return fruit

class FruitsWithColorsContextSetter_Choose(Action):
    def onConfigure(self):
        self.withLabel("Choose a fruit").withDescription("Choose a fruit. The action icon has a custom color.").withArgs([
            createFruitWithColorRecordType("chosenFruit").withNullable().withFeature("visible", False).withProvided(
                ProvidedMeta().withValue().withImplicitMode()),
            ListType("fruits").withLabel("Fruits").withElement(
                    createFruitWithColorRecordType("fruit").withProvided(ProvidedMeta().withSubmittable())
                ).withProvided(
                    ProvidedMeta().withValue().withDependency("chosenFruit").withOptionalMode().withOverwrite()
                ).withFeatures({"activateAction":"submit"})
        ]).withResult(createFruitWithColorRecordType())
        self.withFeatures({"callLabel":"Choose", "icon":IconInfo("palm-tree").withColor("00FF00"), "visible":True})

    def onCall(self, chosenFruit, fruits):
        if chosenFruit:
            chosenFruit.valueLabel = None
        return chosenFruit

    def onProvideArgs(self, context):
        chosenFruit = None
        if "fruits.fruit" in context.submit:
            chosenFruit = context.current["fruits.fruit"]

        if "chosenFruit" in context.provide or "fruits.fruit" in context.submit:
            context.provided["chosenFruit"] = ProvidedValue().withValue(chosenFruit)

        if "fruits" in context.provide or "fruits.fruit" in context.submit:
            if chosenFruit is None:
                chosenFruit = context.current["chosenFruit"]
            chosenFruitName = chosenFruit.value["name"] if chosenFruit else None

            context.provided["fruits"] = ProvidedValue().withValue([
                AnnotatedValue({"name":"Kiwi", "color":"green"}).withValueLabel("Kiwi").withFeature("icon", "star" if chosenFruitName == "Kiwi" else None),
                AnnotatedValue({"name":"Banana", "color":"yellow"}).withValueLabel("Banana").withFeature("icon", "star" if chosenFruitName == "Banana" else None)
            ])

Figure 47. The choose dialog parent action

Figure 48. The choose dialog action

4. Settings

Figure 49. The application settings

5. User experience

Figure 50. The application light theme

The application may be switched to the dark or the light theme in the settings.

6. Supported Sponge concepts

6.1. Data types

Table 1. Data types
Type	Description
`AnyType`	Not supported.
`BinaryType`	Editing (as an action attribute) is supported only for `image/png` mime type with `drawing` characteristic feature. Viewing is supported for image formats supported by Flutter and other binary content supported by the `open_file` Flutter plugin that is used by the application.
`BooleanType`	Supported.
`DateTimeType`	Viewing supported. Editing is currently limited to the `DATE_TIME` date kind.
`DynamicType`	A limited support. This functionality is experimental. A new dynamic value can be created only on the server side, i.e. in an `onProvideArgs` action callback method. A provided `DynamicValue.type` name will be ignored because a name of a parent dynamic type is used in the application.
`IntegerType`	Supported.
`ListType`	Editing is supported with limitations (see the Advanced use cases chapter). A unique list with a provided element value set is represented as a multichoice widget. Viewing is not supported. This functionality is experimental.
`MapType`	Not supported.
`NumberType`	Supported.
`ObjectType`	Supported only if an object type defines a companion type that is supported.
`RecordType`	Editing supported. Viewing support is limited to fields that have simple data types. This functionality is experimental.
`StreamType`	Not supported.
`StringType`	Supported.
`TypeType`	Not supported.
`VoidType`	Supported. A `chip` widget is presented as an editor. A user can tap the chip widget to submit an argument if it is configured as submittable.

6.2. Data type formats

Table 2. Supported data type formats
Format	Description
`phone`	A phone number format. Applicable for `StringType`.
`email`	An email format. Applicable for `StringType`.
`url`	A URL format. Applicable for `StringType`.
`console`	A console format. Text is presented using a monospaced font. Applicable for `StringType`.
`markdown`	A Markdown format. Applicable for `StringType`.

6.3. Features

Table 3. Supported features
Feature	Type	Applies to	Description
`visible`	`boolean`	Action	If `True`, an action will be visible in the main list of actions in the application. Defaults to `true`.
`visible`	`boolean`	Type	If `True`, an action argument or a record field is visible in the action call screen. Defaults to `true`.
`visible`	`boolean`	`GeoLayer`	If `True`, a map layer will be initially visible on a map. Defaults to `true`.
`enabled`	`boolean`	Type	If `True`, an action argument or a record field is enabled for editing. Defaults to `true`.
`refreshable`	`boolean`	`ListType`	If `True`, a provided list will have a button to refresh (i.e. provide arguments from the server). Defaults to `false`.
`icon`	`IconInfo` or `String`	Action	An action icon. The icon feature converter supports an instance of `IconInfo` or `String` (an icon name) as a value. The supported set of icon names is limited to the material design icons (currently v5.0.45).
`icon`	`IconInfo` or `String`	Type	A type icon. Currently supported only for list elements.
`icon`	`IconInfo` or `String`	`GeoMarkerLayer`	A map marker layer icon. Shows a layer marker on a map as a specified icon.
`widget`	`String`	Type	A GUI widget type. See the table below for supported values. Support for this feature is limited. In most cases a default, opinionated widget will be used.
`group`	`String`	Type	A name of a group of action arguments or record fields. Grouped values will be placed in a compact GUI panel close to each other, if it is possible.
`group`	`String`	`GeoLayer`	Map layers that have the same `group` will be grouped and only one of them will be visible at the same time.
`key`	`String`	Action argument type	A name of other argument whose value will be used as a key (or a key fragment) of a GUI widget. For example it enables saving a scroll position in a list. This feature is experimental and is currently implemented only for pageable lists.
`responsive`	`boolean`	Type	A responsive GUI widget. If this feature is set for a provided type, every change in GUI will cause invoking a `provideActionArgs` operation. This feature may be resource consuming (especially when used with an argument submit option) because of possible many server roundtrips.
`confirmation`	`boolean`	Action	If `True` then before calling the action a confirmation dialog will be shown. Defaults to `false`.
`characteristic`	`String`	Type	A value of this feature indicates a special meaning of the type.
`filename`	`String`	`BinaryType`	A filename associated with a binary value.
`intent`	`String`	Action	An action with an intent is handled by the application in a specific way.
`intent`	`String`	Type	A type with an intent is handled by the application in a specific way.
`refreshEvents`	`List<String>`	Action	Refresh event names for an action.
`handlerAction`	`String`	Event type	An event handler action name.
`multiline`	`boolean`	`StringType`	If `True`, a string will be multilined in the GUI. Defaults to `false`.
`maxLines`	`int`	`StringType`	A maximum number of lines in the GUI.
`obscure`	`boolean`	`StringType`	If `True`, a string will be obscured in the GUI, e.g. in case of passwords. Defaults to `false`.
`showCall`	`boolean`	Action	An action call button will be shown in the action call screen. Defaults to `true`.
`showRefresh`	`boolean`	Action	An action arguments refresh button will be shown in the action call screen. Defaults to `false`. The refresh button fetches provided action arguments from the server. Only arguments provided with read only or overwrite flags will be refreshed.
`showClear`	`boolean`	Action	An action arguments clear button will be shown in the action call screen. Defaults to `false`. The clear button resets the action argument values.
`showCancel`	`boolean`	Action	A cancel button will be shown in the action call screen. Defaults to `false`.
`callLabel`	`String`	Action	An action call button label in the action call screen. Defaults to `RUN` if the feature is not set. If set to `None`, the button will not be shown.
`refreshLabel`	`String`	Action	An action refresh button label in the action call screen. Defaults to `REFRESH` if the feature is not set. If set to `None`, the button will not be shown.
`clearLabel`	`String`	Action	An action clear button label in the action call screen. Defaults to `CLEAR` if the feature is not set. If set to `None`, the button will not be shown.
`cancelLabel`	`String`	Action	An action cancel button label in the action call screen. Defaults to `CANCEL` if the feature is not set. If set to `None`, the button will not be shown.
`contextActions`	`List<String>`	Action, `RecordType`, `ListType` action argument	Context actions. For more information on context actions and sub-actions see the Advanced use cases chapter.
`cacheableArgs`	`boolean`	Action	A flag indicating that the action argument values can be cached (i.e. preserved between this action call screens) in a client. Defaults to `true`.
`cacheableContextArgs`	`boolean`	Action	A flag indicating that argument values of the action that is used as a context action can be cached (i.e. preserved between this action call screens) in a client. Defaults to `false`. If set to `true` the `cacheableArgs` should be `true` as well.
`createAction`	`String`	`ListType` action argument	A create sub-action for a list element.
`readAction`	`String`	`ListType` action argument	A read sub-action for a list element.
`updateAction`	`String`	`ListType` action argument	A update sub-action for a list element.
`deleteAction`	`String`	`ListType` action argument	A delete sub-action for a list element.
`activateAction`	`String`	`ListType` action argument	An action that will be called on list element tap. If the action string has the special value `submit`, then instead of calling an action, a `provideActionArgs` will be invoked with the submitted list element.
`width`	`int`	`BinaryType` drawing	An image width.
`height`	`int`	`BinaryType` drawing	An image height.
`strokeWidth`	number	`BinaryType` drawing	A drawing stroke width.
`background`	`String`	`BinaryType` drawing	A drawing background color.
`color`	`String`	`BinaryType` drawing	A drawing pen color.
`color`	`String`	`GeoMap`	A map background color.
`opacity`	`boolean`	`GeoTileLayer`	A map tile layer opacity as a double value between 0 and 1.
`scroll`	`boolean`	`ListType`	A flag indicating that a list will have its own scroll. This feature turns off the main scroll in an action screen. It is useful for long lists. This feature is only supported for main action arguments (i.e. not nested). Defaults to `false`.
`geoMap`	`GeoMap`	`ListType`	Shows list elements in a geographical map. List elements should be of an annotated type and should contain geo position annotations. Supports XYZ tiling schemes as basemaps for list data. A `ListType` that has this feature should not be pageable.
`tms`	`boolean`	`GeoTileLayer`	A flag that informs if a tile layer service is TMS. Defaults to `false`.

Colors are represented by a hexadecimal value specified with RRGGBB (Red, Green, Blue), e.g. "FF0000".

A number can be an integer or a floating point value.

6.3.1. Intents

Table 4. Supported values for the `intent` feature
Intent	Applies to	Description
`login`	Action	Should be set in an action that represents a user login in the user management functionality. See the user management example project.
`logout`	Action	Should be set in an action that represents a user logout in the user management functionality.
`signUp`	Action	Should be set in an action that implements a user sign up in the user management functionality.
`subscription`	Action	Should be set in an action that manages event subscriptions.
`defaultEventHandler`	Action	A default event handler action.
`reload`	Action	Should be set in an action that reloads knowledge bases. Refreshes actions cached in a mobile application.
`reset`	Action	Refreshes actions cached in a mobile application after an action call.
`username`	Action argument type	Indicates that the action argument represents a username. Applies only to actions that implement the user management functionality. This intent may be omitted if an action argument name is `username`.
`password`	Action argument type	Indicates that the action argument represents a password. Applies only to actions that implement the user management functionality. This intent may be omitted if an action argument name is `password`.
`eventNames`	Action argument type	Indicates that the action argument represents event names to subscribe. Applies only to event subscription actions.
`subscribe`	Action argument type	Indicates that the action argument represents a flag telling if to turn on or off an event subscribtion. Applies only to event subscription actions.

6.3.2. Characteristic

Table 5. Supported values for the `characteristic` feature
Characteristic	Applies to	Description
`drawing`	`BinaryType`	A `BinaryType` that represents a drawing. Currently supported only for the `image/png` mime type.
`color`	`StringType`	A `StringType` that represents a color as a hexadecimal RGB string.

6.3.3. Widgets

Table 6. Supported widget types for the `widget` feature
Widget	Description
`slider`	Supported for an `IntegerType` but only if it has min and max values defined. The default behaviour of a slider is lazy, i.e. a value is set on an end of drag. If an integer type has a `responsive` feature set to `true`, the value will be set while dragging.
`switch`	Supported for a `BooleanType`. The default widget for `BooleanType` is a checkbox.

A data type property can be dynamically overwritten by a corresponding feature in an AnnotatedValue. The feature name has to be exactly the same as the data type property name. The overwrite is handled by the Sponge Remote.

6.3.4. List pagination

Table 7. List pagination features
Feature	Type	Applies to	Description
`pageable`	`boolean`	`ListType`	If `True`, a list will be pageable. Defaults to `false`. A pageable list type has to be annotated, because values of offset, limit and count are passed by features in an annotated list value. A pageable list is assumed to have the `scroll` feature set to `true`.
`offset`	`int`	`ListType` annotated value	An offset of the first element of a page.
`limit`	`int`	`ListType` annotated value	A limit of a page, i.e. a maximum number of elements in a page.
`count`	`int`	`ListType` annotated value	A count of all available elements of a list. This value is optional.
`indicatedIndex`	`int`	`ListType` annotated value	An optional index of a single indicated element in a list. This feature is experimental and is implemented only for pageable lists with a limited functionality. If an element is indicated, the GUI will show a button enabling a user to jump to that element (but only if a page containing such element is already loaded from the server). Another limitation is that a jump resets a saved scroll position of a list. To use this feature in the application, you have to turn the application setting "Use scrollable indexed list" on.

A pagination uses the provideActionArgs REST API operation. The features offset and limit have to be set when invoking provideActionArgs. A provided, annotated list must have the offset and the limit set and optionally the count. A client code is responsible for setting offset and limit. An action onProvideArgs callback method is not required to support offset or limit if they are not set in the request. A page size is established by a client code.

The pagination is supported only for primary (i.e. not nested) action arguments and only for read provided annotated lists.

The pagination works only forward, i.e. all previous list elements fetched from the server are stored in mobile device memory.

6.3.5. Geographical map

A geographical map feature is represented by the GeoMap class that contains layers as instances of GeoLayer:

GeoTileLayer represents a tile layer,
GeoMarkerLayer represents marker layers.

A geographical position is represented by GeoPosition.

Table 8. Map (`GeoMap`) properties
Property	Type	Description
`center`	`GeoPosition`	A map center.
`zoom`	`Double`	A map zoom.
`minZoom`	`Double`	A map minimum zoom.
`maxZoom`	`Double`	A map maximum zoom.
`layers`	`List<GeoLayer>`	Map base layers.
`features`	`Map<String, Object>`	Map features.

Table 9. Common map layer (`GeoLayer`) properties
Property	Type	Description
`name`	`String`	A layer name.
`label`	`String`	A layer label.
`description`	`String`	A layer description.
`features`	`Map<String, Object>`	Layer features.

Table 10. Additional map tile layer (`GeoTileLayer`) properties
Property	Type	Description
`urlTemplate`	`String`	A tile service URL template.
`subdomains`	`List<String>`	An optional list of map server subdomains, e.g. `GeoLayer("https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png").withSubdomains(["a", "b", "c"])`.
`options`	`Map<String, String>`	Additional layer options.

Table 11. Geographical position (`GeoPosition`) properties
Property	Type	Description
`latitude`	`Double`	Latitude.
`longitude`	`Double`	Longitude.

7. Customized applications

Access to actions in the Sponge Remote is generic. However you could build a customized GUI using your own Flutter code using the upcoming Sponge Flutter API library.

7.1. Sponge Digit Recognition

The Sponge Digit Recognition mobile application is an example of using a customized Flutter UI.

The Sponge Digit Recognition application is currently under development and is not officially published. It will be released as an open source.

Figure 51. The digit recognition - drawing a digit

The application allows drawing a digit that will be recognized by a Sponge action. After each stroke the remote action call is made and the result is shown in the circle.