title: Rails render partial Ajax Error BUT correct response shown in Debugger
body: <p>I'm trying to trigger an additionnal ajax query on an existing link using unobstrusive Javascript.</p>
  
  <p>The Query is going to the server and processed, returning for the test the string "javascript template ok".</p>
  
  <p>But, the ajax "success" function is never called. In place, it is the "error" function that is triggered...</p>
  
  <p>I looked in the Chrome Debugger and I can see the response text coming back from the server, but never is the "success" method called... :-(</p>
  
  <p>My call is </p>
  
  <pre><code>jQuery.ajax({
      type: 'POST',
  
      success: function(response) {   
          $("#details").html(response);
          console.log(response);
      },
      error: function(){ 
          alert("Error\nData could not be retrieve from the server");
      },
      url: '/treeview/show/1538.js',
      cache: false,
  });
  </code></pre>
  
  <p>(url is harcoded in this example). The same Url in the browser gets the correct data with no layout :-)</p>
  
  <p>Removing the ".js" in the url returns the html template with layout and the update of the "details" div is achieved correctly...</p>
  
  <p>The controller is </p>
  
  <pre><code>    respond_to do |format|
        format.html # show.html.erb
        format.js   { render :inline =&gt; "JAVASCRIPT TEMPLATE !" }
      end
  </code></pre>
  
  <p>Thank you </p>
  
  <p>EDIT :</p>
  
  <p>Here is the object returned from the ajax query (first argument of error: function(jqXHR) ):</p>
  
  <pre><code>Object
      abort: function ( statusText ) {
      always: function () {
      complete: function () {
      done: function () {
      error: function () {
      fail: function () {
      getAllResponseHeaders: function () {
      getResponseHeader: function ( key ) {
      overrideMimeType: function ( type ) {
      pipe: function ( /* fnDone, fnFail, fnProgress */ ) {
      progress: function () {
      promise: function ( obj ) {
      readyState: 4
      responseText: "JAVASCRIPT TEMPLATE !"
      setRequestHeader: function ( name, value ) {
      state: function () {
      status: 200
      statusCode: function ( map ) {
      statusText: "OK"
      success: function () {
      then: function ( /* fnDone, fnFail, fnProgress */ ) {
      __proto__: Object
  </code></pre>
  
  <p>So I get the correct response text ??!! Where can be the error then ? :-s</p>