alexa-ability-context

Simplify building multistep conversations with context-aware intent handling.

Example

import { Ability, events } from 'alexa-ability';
import { handleAbility } from 'alexa-ability-lambda-handler';
import { trackContext, context } from 'alexa-ability-context';

// create ability
const app = new Ability({
    applicationId: 'your-app-id'
});


// add middleware to track context
app.use(trackContext());


app.on('OrderPizzaIntent', function(req) {
    req.say('Are you sure you want to order pizza?').send();
});


// check against previous event
app.on(events.yes, context.after('OrderPizzaIntent', function(req) {
    req.say('Are you really really sure?').send();
}));


// do more complex checks with a regex
app.on(events.yes, context.matches(/.*OrderPizzaIntent:AMAZON.YesIntent$/, function(req) {
    orderPizza(function() {
        req.say('Your pizza is on its way!').end();
    });
}));

app.on(events.no, function() {
    req.say('Ok, goodbye.').end();
});

export const handler = handleAbility(app);

API

trackContext(options) -> middleware

A middleware factory that takes an optional options object. The currently supported options are:

• key: defaults to __context__, the session key to store the context between requests.
• property: defaults context, the property to expose the context object as on the request.

req.context

The trackContext middleware will add an additional property to the request object called context. Which will look something like this:

[
    { "event": "launch" },
    { "event": "ExampleIntent" }
]

req.context.now

The object that will be added to the context for future requests. By default it is just { event: 'name' }, but you're free to modify it or add properties however you like.

req.context.destroy()

Clears the context.

req.context.skip()

Causes the req.context.now object to not be persisted.

context

context.after(event, handler) -> handler

Creates a new handler function that only executes when the previous intent matches.

The two arguments are:

• event: an event name
• handler: a standard alexa-ability handler that accepts req and next as arguments.

The string the regex will be tested against will look like this:

FirstIntent:SecondIntent:ThirdIntent

context.matches(regex, handler) -> handler

Creates a new handler function that only executes when the conversation context matches the given regular expression.

The two arguments are:

• regex: a regular expression.
• handler: a standard alexa-ability handler that accepts req and next as arguments.

context.custom(fn, handler) -> handler

Creates a new handler function that only executes when the custom fn returns a true.

The two arguments are:

• fn: a function that takes in the request object and returns true or false.
• handler: a standard alexa-ability handler that accepts req and next as arguments.