README.md: added documentation

README.md

@@ -1,2 +1,122 @@
 # electron-channel
-A dead simple ipc wrapper for electron
+
+> A dead simple ipc wrapper for electron
+
+[![npm](https://img.shields.io/npm/v/electron-channel.svg?style=flat-square)](https://www.npmjs.com/package/electron-channel)
+[![npm](https://img.shields.io/npm/dt/electron-channel.svg?style=flat-square)](https://www.npmjs.com/package/electron-channel)
+[![npm](https://img.shields.io/npm/l/electron-channel.svg?style=flat-square)](https://github.com/jmjuanes/electron-channel)
+
+A very simple way to comunicate between the main and the render process in **electron**. It is based on `ipc` but uses callbacks in the render process instead of event listeners. 
+
+## Example 
+
+An example of sending and handling messages between the render and the main process. The render process will send a request to the main process to read a file. The main process will read the file and send the content of the file to the render process.
+
+### Main process
+
+```javascript
+//Import dependencies
+var fs = require('fs');
+var channel = require('electron-channel/main');
+
+//Register a listener that reads the content of a file and return the file content
+channel('read-file', function(data, done)
+{
+  //Data is an object with the following keys 
+  // data.filename: path to the file to read 
+  // data.encoding: default encoding
+
+  //Read the file 
+  return fs.readFile(data.filename, data.encoding, function(error, content)
+  {
+    //Call the done function with the error and the file content
+    return done(error, content);
+  });
+});
+```
+
+### Render process 
+
+```javascript
+//Import dependencies 
+var channel = require('electron-channel/render');
+
+//Read the content of a file in the main process 
+channel('read-file', { filename: './file.txt', encoding: 'utf8'}, function(error, content)
+{
+  //Check the error reading the file 
+  if(error){ /* do something with the error */ } 
+
+  //Work with the content of the file 
+  // ...
+});
+```
+
+## API 
+
+### Main process 
+
+Import the channel manager in the main process by adding the following line: 
+
+```javascript
+var channel = require('electron-channel/main');
+```
+
+#### channel(name, listener)
+
+Register a new channel that will listen to all events with the name `name`. For each request to this channel the `listener` function will be executed. 
+
+The `listener` method will be executed with the following arguments: 
+
+- `data`: an object with the data sent by the render process. 
+- `done`: a function used to reply to the render process. All the arguments passed to the `done` function will be the arguments of the callback function in the render process, so you can use it to reply data to the render process.
+
+Example: 
+
+```javascript
+var channel = require('electron-channel/main'); 
+
+//Register a channel 
+channel('name', function(data, done)
+{
+  //Work with the data object 
+  //... 
+
+  //Reply to the render process 
+  return done();
+});
+```
+
+### Render process 
+
+Import the channel manager in the render process by adding the following line: 
+
+```javascript
+var channel = require('electron-channel/render');
+```
+
+#### channel(name, data, callback)
+
+Emit a new request to the main process with the name `name`. The `data` argument must be an object with all the information that will be passed to the main process. 
+
+When the `done` function in the main process is called, the `callback` function will be executed with all the arguments passed to the `done` function in the main process. 
+
+Example: 
+
+```javascript
+var channel = require('electron-channel/render');
+
+//Create the object will all the data that you want to pass to the main process 
+var obj = { ... };
+
+//Emit a new request/message to the main process 
+channel('name', obj, function()
+{
+  //Work with the response 
+  //...
+});
+```
+
+## License 
+
+[MIT LICENSE](./LICENSE) © Josemi Juanes.