# Paloma **This README is for Paloma 4 only.** **For version 3 README please go [here](https://github.com/kbparagua/paloma/blob/3.0/README.md).** **For version 2 README please go [here](https://github.com/kbparagua/paloma/blob/2.0/README.md).** ## Paloma 4, why so sudden? The last major version (v3) of Paloma introduced a major paradigm shift, and it took me a while to realize that some of the major changes introduced are not really that good and needed to be removed. ## What's new? *(compared to version 2)* It is now simpler and more flexible. The old callback thingy paradigm is replaced by a `Controller` layer for better abstraction. Generators are also removed, so programmers need not to follow specific directory structure, unlike in the old versions. Previously, there are generators that create Paloma files, and these files are written in vanilla javascript. Because of that there are some users who are requesting for coffeescript setup. Now since there are no generated files programmers can write their code either by using vanilla javascript or **coffeescript**. Yay! ### Controller The new paradigm is patterned after Rails Controller, so it is easier to grasp than the old callback paradigm. Basically, you have a Paloma Controller counterpart for every Rails Controller. ### How about Model and View? It is tempting to convert Paloma 3 to a full-blown MVC or MVP (or whatever) framework. But I've decided to keep it simple and just provide a Controller component as way to execute a specific javascript code per Rails Controller action and give developers freedom on how to handle each action. So you can still have your own Model and View components and just use them in your Paloma Controllers, since a controller is just a middle-man. ## Advantages * Choose what specific javascript code to run per page. * Easily make ruby variables available on your javascript files. ## Quick Example Paloma controller. ```javascript var UsersController = Paloma.controller('Users'); // Executes when Rails User#new is executed. UsersController.prototype.new = function(){ alert('Hello Sexy User!' ); }; ``` The Rails controller `app/controllers/users_controller.rb`: ```ruby def UsersController < ApplicationController def new # a Paloma request will automatically be created. @user = User.new end end ``` That's it! Simply Sexy! ## Minimum Requirements * jQuery 1.7 or higher * Rails 3.1 or higher ## Install * Without bundler: `sudo gem install paloma`. * With bundler, add this to your Gemfile: `gem 'paloma'` * Require `paloma` in your `application.js`: `//= require paloma` ## Controllers Controllers are just classes that handle requests made by Rails Controllers. Each Rails Controller's action will be mapped to a specific Paloma Controller's action. ### Creating a Controller A Controller constructor is created or accessed (if it already exists), using `Paloma.controller()` method. ```javascript var ArticlesController = Paloma.controller('Articles'); ``` It will return the constructor function of your controller. Note: Using `Paloma.controller` method, you can access the same controller constructor across different files. ### Handling Actions Every time a request to Paloma is made (A Rails Controller action is executed), an instance of a Paloma controller is created and the method responsible for the request will be invoked. ```javascript var ArticlesController = Paloma.controller('Articles'); ArticlesController.prototype.new = function(){ // Handle new articles }; ArticlesController.prototype.edit = function(){ // Handle edit articles }; ``` ## Advanced Usage You can manipulate what controller/action should Paloma execute by calling `js` method **before** rendering. 1. Changing controller ```ruby class UsersController < ApplicationController def new @user = User.new js 'Accounts' # will use Accounts controller instead of Users controller end end ``` 2. Changing action You can use the symbol syntax: ```ruby def new @user = User.new js :register # will execute register method instead of new end ``` Or the string syntax: ```ruby def new @user = User.new js '#register' end ``` 3. Changing controller and action. ```ruby def new @user = User.new js 'Accounts#register' # will execute Accounts#register instead of Users#new end ``` 4. Changing controller with namespace. Paloma supports namespaces using '/' as delimiter. ```ruby def new @user = User.new js `Admin/Accounts` # will use Admin/Accounts controller instead of Users controller end ``` ```ruby def new @user = User.new js 'Admin/Accounts#register' # will execute Admin/Accounts#register instead of Users#new end ``` ## Passing Parameters You can access the parameters on your Paloma Controller using `this.params` object. 1. Parameters only. `users_controller.rb` ```ruby def destroy user = User.find params[:id] user.destroy js :id => user.id end ``` Paloma controller. ```javascript var UsersController = Paloma.controller('Users'); UsersController.prototype.destroy = function(){ alert('User ' + this.params['id'] + ' is deleted.'); }; ``` 2. Path with parameters. ```ruby def destroy user = User.find params[:id] user.destroy js 'Accounts#delete', :id => user.id end ``` ## Preventing Paloma Execution If you want to Paloma not to execute in a specific Rails Controller action you need to pass `false` as the Paloma parameter. ```ruby def edit @user = User.find params[:id] js false end ``` ## Controller-wide setup You can call `js` outside Rails controller actions for global or controller-wide settings. **Example:** ```ruby class UsersController < ApplicationController js 'Accounts' # use Accounts controller instead of Users for all actions. def new @user = User.new end def show @user = User.find params[:id] end end ``` Like `before_filter` you can also pass `only` and `except` options. ```ruby class UsersController < ApplicationController js 'Admin/Accounts', :except => :destroy # Use Admin/Accounts except for destroy method end ``` **IMPORTANT NOTE:** If you are going to pass parameters for Controller-wide settings, put them inside a `:params` hash. ```ruby class UsersController < ApplicationController js 'Accounts', :params => {:x => 1, :y => 2, :z => 3}, :only => :show end ``` ### Overriding Controller-wide setup If you want to override the controller-wide setup, just call `js` again inside a controller action. From there you can override the controller/action or pass additional parameters. ```ruby class UsersController < ApplicationController js 'Accounts', :params => {:x => 1} def new @user = User.new js :register, :y => 2 # will execute Accounts#register with params {:x => 1, :y => 2} end end ``` ## Turbolinks Support As of version `4.1.0`, Paloma is compatible with Turbolinks without additional setup. ### Execute Paloma when user hits `Back` or `Forward` button. Paloma executes page-specific javascript by adding a `