gardr-core-plugin

gardr-core-plugin

The PluginApi and pluginHandler used for both host and ext side plugin functionality. It has no dependencies to Garðr or any other libraries.

To make plugins decoupled from the Garðr-code we have plugins as a pub-sub. They are triggered syncronously, so plugins can change the object that is passed along. In Garðr we use event names like: "{object}:{event}". For instance "params:parsed" is triggered right after we've parsed the parameters from the URL in gardr-ext. The params object is passed as the event data. If a plugin needs to change the script URL before it's written, it can just change the value of params.url. Also "item:afterrender" is triggered after an item (banner) has finished loading, and the item object is passed as the event data.

This module exposes two objects:

var pluginCore = require('gardr-plugin-core');
pluginCore.PluginApi; // the API-object constructor
pluginCore.pluginHandler; // used to register and initialize plugins

It works by exposing a metod that pass plugins to pluginHandler.register. Then call pluginHandler.initPlugins with a new instance of PluginApi and the options object (if they need it).

var pluginApi;

module.exports = {
    plugin: function (pluginFn) {
        pluginCore.pluginHandler.register(pluginFn);
    },

    init: function (options) {
        pluginApi = new pluginCore.PluginApi();
        pluginCore.pluginHandler.initPlugins(pluginApi, options);
    }
};

Plugin functions have two parameters; pluginApi and options (same options as above).

module.exports = function (pluginApi, options) {
    // Could check options for plugin configuration or read/change the main module´s options

    pluginApi.on('eventname', function (obj) {
        obj.foo = 'bar';
    });
};

To trigger events:

var obj = {foo: null};
pluginApi.trigger('eventname', obj);
console.log( obj.foo ); // 'foo'