Rails render partial Ajax Error BUT correct response shown in Debugger

Question

I'm trying to trigger an additionnal ajax query on an existing link using unobstrusive Javascript. The Query is going to the server and processed, returning for the test the string "javascript template ok". But, the ajax "success" function is never called. In place, it is the "error" function that is triggered... 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... :-( My call is ``` jQuery.ajax({ type: 'POST', success: function(response) { $("#details").html(response); console.log(response); }, error: function(){ alert("Error
Data could not be retrieve from the server"); }, url: '/treeview/show/1538.js', cache: false, }); ``` (url is harcoded in this example). The same Url in the browser gets the correct data with no layout :-) Removing the ".js" in the url returns the html template with layout and the update of the "details" div is achieved correctly... The controller is ``` respond_to do |format| f…

Accepted Answer

You do not explicitly specify the `dataType` option for `jQuery.ajax` so jQuery infers it to be `script` (relying on MIME type served by Rails). Since `JAVASCRIPT TEMPLATE !` is not a valid Javascript statement, parser error is thrown. There are two options to get `success` callback called instead of `error`:

Explicitly specify `dataType` as `text`:

```
jQuery.ajax({
    type: 'POST',
    dataType: 'text',
    // ...
});
```

Or return valid Javascript from controller:

```
respond_to do |format|
  format.html # show.html.erb
  format.js { render :inline => "{}" }
end
```

Rails render partial Ajax Error BUT correct response shown in Debugger

Solution

Problem