CODEWITHSUNDEEP
jqueryruby-on-railsajaxjson
Macario Ortega
Macario Ortega

Reputation:

How do I PUT JSON data to Ruby on Rails using jQuery?

I am trying to send a jQuery Ajax PUT request that looks like this:

$.ajax({
      type: "PUT",
      url: '/admin/pages/1.json',
      data: { page : {...} },
      dataType: 'json',
      success: function(msg) {
        alert( "Data Saved: " + msg );
      }
});

My controller looks roughly like this:

      respond_to do |format|
         if @page.update_attributes params[:page]
           format.html{ ... }
           format.json{ render :json => {:saved => 'ok'}.to_json }
         else
           format.html{ ... }
           format.json{ render :json => {:saved => 'fail'}.to_json }
         end
       end

but I get the following error.

The error occurred while evaluating nil.name /Library/Ruby/Gems/1.8/gems/activesupport-2.3.2/lib/active_support/xml_mini/rexml.rb:29:in merge_element!' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.2/lib/active_support/xml_mini/rexml.rb:18:inparse' (DELEGATION):2:in __send__' (__DELEGATION__):2:inparse' /Library/Ruby/Gems/1.8/gems/activesupport-2.3.2/lib/active_support/core_ext/hash/conversions.rb:154:in `from_xml' ... ...

It is like Ruby on Rails is trying to parse the parameters as XML, but I want to use JSON!

What shall I do to put JSON to Ruby on Rails?

Upvotes: 15

Views: 16232

Answers (5)

Marc-André Lafortune
Marc-André Lafortune

Reputation: 79552

You need to set contentType to "application/json" in your options; dataType is only what you expect back.

Also, you need to serialize your data field using JSON.stringify:

$.ajax({
    type: "PUT",
    url: '/admin/pages/1.json',
    data: JSON.stringify({ page :  {...} }),
    contentType: 'application/json',
    dataType: 'json',
    success: function(msg) {
        alert( "Data Saved: " + msg );
    }
})

Upvotes: 1

Macario Ortega
Macario Ortega

Reputation:

Setting the contentType didn't work for me. I was getting a string instead of a hash for params[:page].

So I solved it like this:

Stringifying the JSON object with a script found at JSON in JavaScript:

$.ajax({
    type: "PUT",
    url: '/admin/pages/1.json',
    data: { page : JSON.strigify( {...} ) },
    dataType: 'json',
    success: function(msg) {
        alert( "Data Saved: " + msg );
    }
});

On the Ruby on Rails side, a JSON gem must be required. In the controller:

 params[:page] = JSON.parse params[:page] if params[:page].is_a? String

It is not pretty at all, but it worked for me.

Upvotes: 7

Seth Ladd
Seth Ladd

Reputation:

Also, head's up, but there's a bug in Ruby on Rails 2.3.2 that prevents this from working. See Ruby on Rails 2.3 JSON "put" request routing is broken

Upvotes: 2

Stefano
Stefano

Reputation: 21

If you don't want to add scripts, you could do

$.parseJSON("some_jsonish_string")

Upvotes: 2

Craig Stuntz
Craig Stuntz

Reputation: 126547

You need to set contentType in your options. contentType is what you are sending. dataType is what you expect back. You should carefully read the documentation on the options argument to ajax.

Upvotes: 5

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