State

When a Flow is triggered and the trigger has Arguments, an event is fired for you to validate the arguments, for each Flow that has this trigger. This is a chance to validate the user's value for the trigger's arguments.

For example, we expand on the rain example with a 'Location' field for the user to choose.

/app.json

{
  "id": "com.athom.example",
  ...
  "flow": {
    "triggers": [
      {
        "id": "rain_start",
        "title": {
          "en": "It starts raining"
        },
        "tokens": [
          {
            "name": "mm_per_hour",
            "type": "number",
            "title": {
              "en": "mm/h"
            },
            "example": 5
          }
        ],
        "args": [
          {
            "name": "location",
            "type": "text"
          }
        ]
      }
    ]
  }
}

/app.js

// register the card
let rainStartTrigger = new Homey.FlowCardTrigger('rain_start');
rainStartTrigger
  .registerRunListener(( args, state ) => {

    console.log(args); // { 'location': 'New York' }, this is the user input
    console.log(state); // { 'location': 'Amsterdam' }, this is the state parameter, as passed in trigger()

    // If true, this flow should run
    return Promise.resolve( args.location === state.location );

  })
  .register()


// trigger the card
let tokens = { 'mm_per_hour': 3 }
let state = { 'location': 'Amsterdam' }

rainStartTrigger.trigger( tokens, state )
  .then( this.log )
  .catch( this.error )