replyAsync Example

This example demonstrates using replyAsync function. You should use replyAsync instead of reply if you have subroutines that return promises.

Important Note About Conditionals

Asynchronous object macros are not supported within the conditional side of *Conditions in RiveScript. That is, RiveScript code like the following will not work (where the weather macro calls out to an HTTP API and returns a promise with the result):

+ is it sunny outside
* <call>weather <get zipcode></call> == sunny => It appears it is!
- It doesn't look sunny outside.

Conditionals in RiveScript require their results to be immediately available so it can check if the comparison is truthy. So, even if you use replyAsync(), the <call> tags in conditionals only support running synchronous object macros (ones that return a string result and not a promise).

However, asynchronous object macros can be used in the reply portion of the conditional (the part on the right side of the => separator). This is the text eventually returned to the user and it can return as a promise when you use replyAsync() just like if it were in a -Reply command.

Running the example

To fully experience this example, you'll need to get an API key from OpenWeatherMap (don't worry, they're free!), and edit weatherman.js to fill in your APPID near the top of the file.

npm install && node weatherman.js

Refer to weatherman.rive for the list of supported commands

Using async subroutines

Whenever you have a subroutine that needs to call some sort of asynchronous function in order to return a value back to the script, you should use promises:

var rs = new RiveScript();
rs.setSubroutine("asyncHelper", function(rs, args) {
  // RiveScript comes bundled with RSVP.js which you can
  // access through RiveScript.Promise alias
  // but you are free to use your own Promise implementation
  return new rs.Promise(function(resolve, reject) {
    resolve('hello there');
  });
})

Async responses in RiveScript come in 2 flavors:

// using promises
rs.replyAsync(username, message).then(function(reply) {
  // good to go
}).catch(function(error){
  // something went wrong
});

// or using callbacks
rs.replyAsync(username, message, this, function(error, reply) {
  if (!error) {
    // you can use reply here
  } else {
    // something went wrong, error has more info
  }
});