Hooks

Description

A hook is just a callback function that gets executed whenever a piece of data passes by the dispatcher in the course of a data flow. Multiple hooks can be tied to a single flow. Each hook can be set to run when the message object comes in (input hook) or when the response goes out (output hook).

Hooks must extend the base Hook class.

Difference with handlers

The handler can generate and return a response. Hooks can run on the response as well on the data.

Exposed Methods

Methods that must be implemented

process(data) - The hook body, the function that will be executed.

Methods present in the base class

run(data) - Receives the data from the dispatcher and calls process().

Exposed Properties

Getters that must be implemented

path (string) - Returns the path of the hook file.

Sample implementation
```
    get path() {
        return __filename;
    }
```

Getters present in the base class

name (string) - Returns the handler name.
config (string) - Returns the config object.

Setters present in the base class

config (string) - Sets the config object.

Events

const hook = require('iris-hook-myAwesomeHook');

hook.on('data', function(event){
  console.log('data', event.data);
});

Every event object contains the following properties:

target - The hook that triggered the event.
data - A data object.

Emits

data-hookname - Triggered every time the hook receives a new piece of data/response.