Question

I would like to make my application somewhat REST compliant. I am using Rails on the backend and GWT on the frontend. I would like to do updates and deletes. I realize I can do something like mydomain.com/:id/delete (GET) and accomplish the same thing. However, as I stated previously, I would like to have a REST compliant backend. Thus, I want to do mydomain.com/:id (DELETE) and have it implicitly call my delete method.

Now, it’s my understanding that if a browser (my browser is GWT RequestBuilder) doesn’t support DELETE/GET, Rails somehow accomplishes this task with a POST and some other url parameter. So, how can I accomplish this with a GWT RequestBuilder?

Answer 1

Rails does this with hidden attributes. The easiest way to figure this out would be to create a new rails application, generate a scaffold and have a look at the HTML in a browser.

Try this:

rails jp cd jp ./script/generate scaffold RequestBuilder name:string rake db:migrate ./script/server  

Then navigate to http://localhost:3000/request_builders, click on New and have a look at the HTML. You’ll see something like:

<form action='/request_builders' class='new_request_builder'    id='new_request_builder' method='post'>   <div style='margin:0;padding:0'>     <input name='authenticity_token' type='hidden' value='e76...' />   </div> 

This is a creation, method is POST. Enter a name, save then Edit:

<form action='/request_builders/1' class='edit_request_builder'    id='edit_request_builder_1' method='post'>   <div style='margin:0;padding:0'>     <input name='_method' type='hidden' value='put' />     <input name='authenticity_token' type='hidden' value='e76...' />   </div> 

Of course the form is sent with POST, but Rails hads a hidden field to simulate a PUT request. Same for deletion, but the scaffold will do it with a bit of Javascript:

var m = document.createElement('input');  m.setAttribute('type', 'hidden');  m.setAttribute('name', '_method');  m.setAttribute('value', 'delete'); 

To have this work with another front-end, you’ll have to both:

• Use the same style URL such as /request_builders/1 (RESTful URLs)
• Include the hidden fields (Rails trick)