chat-engine-plugin
v0.0.6
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This repository serves as the docs for PubNub ChatEngine Plugins.
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ChatEngine Plugin Assets
This repository serves as the docs for PubNub ChatEngine Plugins.
Building your first plugin
Plugin.js
The plugin entry file must be a file called plugin.js
in the root directory.
From this file you can require any other file as normal, but the entry must be
plugin.js
Plugin Anatomy
Every plugin must return an object containing the property middleware
or extends
.
Middleware
Middleware allows you to transform payloads as they travel through the system. They are executed in order they are assigned.
The only valid properties of the middleware
object are send
and
broadcast
.
send
is executed before the payload is sent over the network to the rest of the connected clients.broadcast
is executed when the client receives a payload from another client.
module.exports = (config) => {
return {
middleware: {
send:
message: (payload, next) => {
payload.sentTime = new Date();
next(err, payload);
}
},
broadcast:
message: (payload, next) -> {
payload.receiveTime = new Date();
next(err, payload);
}
}
}
};
}
The sub properties under send
and broadcast
are the events
that will trigger the transformation.
For example, the plugin above will be executed when a message
event is sent from the client.
someChat.send('message', {text: 'This triggers the ```send```` method before it\'s published over the wire.'});
someChat.on('message', (payload) => {
// payload has been modified by the ```broadcast``` method before this was called
console.log(payload.receiveTime);
});
#### Extends
You can also extend ChatEngine objects and add new methods to them. For example,
this plugin adds a method called ```newMethod()``` to the ```ChatEngine.Chat``` object.
```js
module.exports - {
return {
extends: {
Chat: {
construct: () => {
// this is called whenever a new Chat is created
// the Chat object is available through this.parent
console.log('I am extending', this.parent);
}
newMethod: (params) => {
// this is a new method that gets attached to Chat
}
}
}
}
}
When the plugin is installed, every instance of ChatEngine.Chat
will have a new
method called newMethod()
. You can call the method like someChat.newMethod()
.
Using Plugins
Node
It's super easy to use plugins in NodeJs. Just include the file like any other dependency and attach it to your ChatEngine objects.
// include the plugin from the remote file
const myPlugin = require('plugin.js');
// create a new chatroom
let someChatroom = new ChatEngine.Chat('new-channel');
// attach the plugin to the new chatroom
someChatroom.plugin(myPlugin(config));
Web
You'll need the chat-engine-plugin
tool described in the next section to
build the package for web.
Once you build the pckage you would include the plugin with a <script>
tag like:
<script src="/web/plugin.js"></script>
And the plugin will be available under ChatEngineCore.plugin[namespace]
.
The namespace is defined in package.json and you can learn more about it in the
next section.
Once the plugi is available, you can attach it to ChatEngine objects like we do in the Node version.
let someChatroom = new ChatEngine.Chat('new-channel');
someChatroom.plugin(ChatEngineCore.plugin.myPlugin(config));
ChatEngine Plugin Tool
This is a build tool for ChatEngine plugins. Because ChatEngine works on the front and back end, the plugin system requires a standardized method for building for web.
This build process assures us that the plugin can be used identically on both web and nodeJS. It uses browserify to compile assets.
It's main features are:
- Name spacing plugins to avoid collisions
- Preventing global scope leak in browser
- Consistent API for integration on web and node
- Singular tests for web and node
Setup
Install the tool globally.
npm install chat-engine-plugin -g
When used in a browser, this will provide your plugin as a property of the
global ChatEngineCore.plugin
property.
ChatEngineCore.plugin.emoji
.
This helps to avoid collisions with global variables. Be careful to avoid collisions with other ChatEngine plugins!
Run chat-engine-plugin
Then, just run chat-engine-plugin
from the command line. This will bundle your
plugin.js
file and it's dependencies so it can be used on the web.
Tests
Tests are defined in test.js
and should use the mocha
test package
with chai
for consistency.
Support
- If you need help, have a general question a feature request or to file a bug, contact [email protected]