id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
12952	[FileLoader] Customization of the communication with the server should be simpler	Artur Delura	Piotr Jasiun	"Working on ticket:12612 we found out that we need to allow user to add flag `withCredentials` and some extra headers to XHR object in filetools plugins. Use case for this is to allow cross domain requests.

Following [https://github.com/ckeditor/ckeditor-dev/blob/major/plugins/filetools/plugin.js#L463-L471 this] example I tried to customize a bit my request object. I end up with:

{{{
CKEDITOR.replace( 'editor', function() {
  CKEDITOR.fileTools.fileLoader.prototype.sendRequest = function() {
	  var formData = new FormData(),
			xhr = this.xhr;

		formData.append( 'upload', this.file, this.fileName );
		xhr.withCredentials = true; // Extra lines
		xhr.setRequestHeader( 'X-PINGOTHER', 'pingpong' ); // Extra lines
		xhr.open( 'POST', this.uploadUrl, true );
		xhr.send( formData );
	};
} );
}}}

Shortcomings of this solution are:
* We overwrite global function `sendRequest` which influence all editor instances while option`imageUploadUrl` is unique for all editor isntances.
* We have to wait for plugin to be loaded and editor instance as well to overwrite this method. If user have got a few editors he have to impelement special mechanism to overwrite this function when first editor instance is loaded. Or maybe there is a global event which fire when plugin is loaded?

We got at least two sulutions for this:
* We can add extra config option like:
{{{
xhrData =  {
    withCredentials: true,
    headers: {
        'X-HEADER-NAME': ""X-HEADER VALUE""
    }
};
}}}

And function send request will take into consideration {{{xhrData}}} config options and set flag and headers. This is simples solution but don't allow user whole freedom.

* Second option is to fire events like `prerequest` which will have an xhr object as a property and user would make whatever he wants with this."	New Feature	closed	Normal	CKEditor 4.5.0 Beta	General		fixed