REST in Place

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REST in Place is an AJAX Inplace-Editor that talks to RESTful controllers. It requires absolutely no additional server-side code if your controller fulfills the following REST preconditions:

• It uses the HTTP PUT method to update a record
• It delivers an object in JSON form for requests with "Accept: application/json" headers

The editor works by PUTting the updated value to the server and GETting the updated record afterwards to display the updated value. That way any authentication methods or otherwise funky workflows in your controllers are used for the inplace-editors requests.

To save the additional GET request, you can take the shortcut of returning the updated record in the response to the PUT request. See the testapp for an example.

URL: http://github.com/janv/rest_in_place/
REPOSITORY: git://github.com/janv/rest_in_place.git
BLOG: http://jan.varwig.org/projects/rest-in-place

If you like REST in Place, you can flattr me:

Requirements

Rails

Since I guess most people use REST in Place in Rails apps, I turned this entire thing into a gem that you can require in your Gemfile. It requires jQuery, but it will NOT install a jquery-rails dependency. This is done so you aren't forced to use jquery-rails if you want to run a more up-to-date version of jQuery. Just make sure that jQuery is there.

REST in Place requires Rails >= 3.1 as a dependency since it loads through the asset pipeline.

CoffeeScript

The CoffeeScript code (lib/assets/javascripts/rest_in_place/rest_in_place.coffee.erb) only relies on the presence of jQuery. You can extract just that file and use it with whatever framework in whatever server-side language you want, given that you follow the coventions described later in this document.

Even though this is processed by ERB to sniff out some relevant Rails settings, you can use it as a CoffeeScript file without modification. (This feature might vanish at any time in the future, tying RIP closer to Rails).

JavaScript only

If you're still using JavaScript, give CoffeeScript a try. It's a preprocessor/different syntax, that makes writing JavaScript bearable. If you absolutely don't want to learn anything new, just convert REST in Place to JavaScript using http://js2coffee.org/ before including it in your project.

Installation

Just add

gem 'rest_in_place'

to your Gemfile.

Then load the JavaScript by adding <%= javascript_include_tag "rest_in_place" %> into your layout. Alternatively you can require 'rest_in_place' in your JavaScript files in app/assets, for example in your application.js:

//= require 'rest_in_place'

In both cases, make sure you load REST in Place after jQuery.

Rails Request Forgery Protection

For REST in Place to work with Rails request forgery protection, you need to have the Rails CSRF meta tags in your HTML head:

<%= csrf_meta_tags %>

Usage Instructions

To make a piece of Text inplace-editable, wrap it into an element (a span usually) with class "rest-in-place". The editor needs 3 pieces of information to work: a URL, an object name and the attribute name. These are provided as follows:

• put attributes into the element, like this:

  <span class="rest-in-place" data-url="/users/1" data-object="user" data-attribute="name">
    <%= @user.name %>
  </span>
  

• if any of these attributes is missing, DOM parents of the element are searched for them. That means you can write something like:

  <div data-object="user" data-url="/users/1">
    Name:  <span class="rest-in-place" data-attribute="name" ><%= @user.name %></span><br/>
    eMail: <span class="rest-in-place" data-attribute="email"><%= @user.email %></span>
  </div>
  

• You can completely omit the url to use the current document's url. With proper RESTful controllers this should always work, the explicit url-attribute is for cases when you want to edit a resource that is displayed as part of a non-RESTful webpage.

• Rails provides the dom_id helper that constructs a dom id out of an ActiveRecord for you. So, your HTML page may look like this:

  <div id="<%= dom_id @user # == "user_1" %>">
    Name:  <span class="rest-in-place" data-attribute="name" ><%= @user.name %></span><br/>
    eMail: <span class="rest-in-place" data-attribute="email"><%= @user.email %></span>
  </div>
  

  REST in Place recognizes dom_ids of this form and derives the object parameter from them, so that (with the current documents url used) you really only need to provide the attributes name in most cases.

  Note that a manually defined (in the element or in one of the parents) object always overrides dom_id recognition.

• REST in Place supports multiple form types. The default type is a input field, a textarea is also supported. To select a form type use the data-formtype attribute in the element and set it to the name of your formtype ( input, or textarea ).

  To write your own form types, just extend the RestInPlace.forms object and select your new form type throught the data-formtype attribute.

Elements with the class rest-in-place are picked up automatically upon document.ready. For other elements, grab them via jQuery and call restInPlace() on the jQuery object.

$('.my-custom-class').restInPlace()

Events

A REST in Place instance triggers four different events on the element that it's associated with:

• activate.rest-in-place when starting the editing of the element.
  Triggering the event is the first thing that happens, before any processing and form building takes place. That means uou can use this event to modify the content of the element (for example to remove number/date formatting).
• success.rest-in-place with the data retrieved from the server as an extra parameter after a successful save on the server.
  This event is triggered at the very latest moment, after the element has been restored with the data from the server. This means you can use the event handler to further modify the data and overwrite the displayed value (useful for number/date formatting for example).
• failure.rest-in-place after an error occured
• update.rest-in-place immediately before sending the update to the server
• abort.rest-in-place when the user aborts the editing process.

Bind to these events through the jQuery event mechanisms:

$('#my-editable-element').bind('success.rest-in-place', function(event, data){
  console.log("Yay it worked! The new value is", data.whatever);
});

Example

Your routes.rb:

resources :users

Your app/controllers/users_controller.rb:

class UsersController < ApplicationController
  def show
    @user = User.find params[:id]
    respond_to do |type|
      type.html
      type.json {render :json => @user}
    end
  end

  def update
    @user = User.find params[:id]
    if @user.update_attributes!(params[:user])
      respond_to do |format|
        format.html { redirect_to( @person )}
        format.json { render :json => @user }
      end
    else
      respond_to do |format|
        format.html { render :action  => :edit } # edit.html.erb
        format.json { render :nothing =>  true }
      end
    end
  end
end

Your app/views/users/show.html.erb:

<div id="<%= dom_id @user %>">
  ID: <%= @user.id %><br />
  Name: <span class="rest-in-place" data-formtype="input" data-attribute="name"><%= @user.name %></span><br/><br/>
  Hobbies: <span class="rest-in-place" data-formtype="textarea" data-attribute="hobbies"><%= @user.hobbies %></span>
</div>

You can run this example by running to the testapp included in this plugin with script/server (sqlite3 required) and visiting localhost:3000/users/

Hint:
you might need to set up the database first. Copy and edit testapp/config/database.yml.sample accordingly. If you don't want to use the included sqlite3 database, run rake db:create and rake db:schema:load.

Troubleshooting

REST in Place is very picky about correct headers and formatting. If you experience errors, please make sure your controller sends responses as properly formatted JSON with the correct MIME-Type "application/json".

Testing

The repository contains a testapp directory with a rails app that can be used to test REST in Place. Just head to http://localhost:3000 to see it in action.

There's also an automated Jasmine spec suite running at http://localhost:3000/jasmine. You can find the sources for the specs at testapp/app/assets/javascripts/spec.coffee

Participation

I'd love to get comments, bug reports (or better, pull-requests) about REST in Place. For this, you can either fork the project to send a pull request, or submit a bug in the tracker at github: http://github.com/janv/rest_in_place/issues

For general comments and questions, please use the comment function on my blog: http://jan.varwig.org/projects/rest-in-place

If you send pull requests be sure to also add tests and make sure the existing tests pass.

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Copyright (c) 2012 [Jan Varwig], released under the MIT license