onCommand handler

Responsible for handling commands sent from the dialog script.

To accompany user’s utterances with activities in the app UI, you can send commands from the dialog scripts to the client app. For example, once the user gives a voice command, another view or page can be opened in the app, a UI element can be selected on the screen and so on.

To send a command, use the play() function in the dialog script and pass a JSON object to it. The JSON object contains the command name and, optionally, arbitrary data to be provided to the app. To handle the command on the client side, set up the logic in the onCommand handler in the app.

For details, see Sending commands to the app.

Examples

Dialog script

intent(`Go to the home page`, p => {
  p.play({command: 'navigation', route: 'home'});
  p.play(`Opening the home page...`);
});

Web (React, Angular, etc.)

Client app

alanBtn({
  key: 'YOUR_KEY_FROM_ALAN_STUDIO_HERE',
  host: 'v1.alan.app',
  onCommand: (commandData) => {
    if (commandData.command === 'go:back') {
      // Call client code that will react to the received command
    }
  },
});

Objective-C

Client app

self.button.onCommand = ^(NSDictionary *command) {
  NSString* commandName = [command objectForKey:@"command"];
  NSLog(@"%@", commandName);
};

Swift

Client app

self.button.onCommand = { command in
  guard let commandName = command?["command"] as? String else {
    return
  }
  print(commandName)
}

Kotlin

Client app

val alanCallback: AlanCallback = object : AlanCallback() {
  /// Handle commands from Alan AI Studio
  override fun onCommand(eventCommand: EventCommand) {
    try {
      val command = eventCommand.data
      val commandName = command.getJSONObject("data").getString("command")
      Log.d("AlanButton", "onCommand: commandName: $commandName")
    } catch (e: JSONException) {
      e.message?.let { Log.e("AlanButton", it) }
    }
  }
};

/// Register callbacks
alanButton?.registerCallback(alanCallback);

Java

Client app

AlanCallback alanCallback = new AlanCallback() {
  /// Handle commands from Alan AI Studio
  @Override
  public void onCommand(final EventCommand eventCommand) {
    try {
      JSONObject command = eventCommand.getData();
      String commandName = command.getJSONObject("data").getString("command");
      Log.d("AlanButton", "onCommand: commandName: " + commandName);
    } catch (JSONException e) {
      Log.e("AlanButton", e.getMessage());
    }
  }
};

/// Register callbacks
alanButton.registerCallback(alanCallback);

Flutter

Client app

_MyHomePageState() {
  /// Handle commands from Alan AI Studio
  AlanVoice.onCommand.add((command) {
    debugPrint("got new command ${command.toString()}");
  });
}

Ionic

Ionic Angular

Client app

this.alanBtnComponent.nativeElement.addEventListener('command', (data) => {
  const commandData = (<CustomEvent>data).detail;
  if (commandData.command === 'navigation') {
     // call client code that will react to the received command
   }
 });

Ionic React

Client app

alanBtnComponent.current.addEventListener('command', (data: CustomEvent) => {
  const commandData = data.detail;
  if (commandData.command === 'navigation') {
     // call client code that will react to the received command
  }
});

Ionic Vue

Client app

<ion-content :fullscreen="true">
  <alan-button v-on:command="command" alan-key="YOUR_KEY_FROM_ALAN_STUDIO_HERE" />
</ion-content>

export default defineComponent({
  methods: {
    command: function(data:any) {
      console.info('Received command: ', data.detail);
    }
  },
});

Note

To define the onCommand handler in Ionic Vue, use lowercase: v-on:command. Otherwise the handler will not be working.

React Native

Client app

import { NativeEventEmitter, NativeModules } from 'react-native';
const { AlanEventEmitter } = NativeModules;
const alanEventEmitter = new NativeEventEmitter(AlanEventEmitter);

componentDidMount() {
  // Handle commands from Alan AI Studio
  alanEventEmitter.addListener('onCommand', (data) => {
    console.log(`onCommand: ${JSON.stringify(data)}`);
  });
}

componentWillUnmount() {
  alanEventEmitter.removeAllListeners('onCommand');
}