How to add responsive class to ckeditor image dialog?

I have website baker that has CK Editor. I want to have images automatically have the class "img-responsive" if no classes are inserted. How? Can i Do that

I cant find a dictionary of this http://docs.cksource.com/CKEditor_3.x/Howto/Default_Field_Values what names are every input and so on? and the html source wont show that.

I had the same problem long time ago. I probably copy-pasted most of the code and I did some minor modification by myself. Its a bit long code, which add img-responsive class to all added images.

 CKEDITOR.replace('editor1');
    CKEDITOR.on('instanceReady', function(ev) {

        //resp. images for bootstrap 3
        ev.editor.dataProcessor.htmlFilter.addRules(
                {
                    elements:
                            {
                                $: function(element) {
                                    // Output dimensions of images as width and height
                                    if (element.name == 'img') {
                                        var style = element.attributes.style;
                                        //responzive images

                                        //declare vars
                                        var tclass = "";
                                        var add_class = false;

                                        tclass = element.attributes.class;

                                        //console.log(tclass);
                                        //console.log(typeof (tclass));

                                        if (tclass === "undefined" || typeof (tclass) === "undefined") {
                                            add_class = true;
                                        } else {
                                            //console.log("I am not undefined");
                                            if (tclass.indexOf("img-responsive") == -1) {
                                                add_class = true;
                                            }
                                        }

                                        if (add_class) {
                                            var rclass = (tclass === undefined || typeof (tclass) === "undefined" ? "img-responsive" : tclass + " " + "img-responsive");
                                            element.attributes.class = rclass;
                                        }

                                        if (style) {
                                            // Get the width from the style.
                                            var match = /(?:^|\s)width\s*:\s*(\d+)px/i.exec(style),
                                                    width = match && match[1];

                                            // Get the height from the style.
                                            match = /(?:^|\s)height\s*:\s*(\d+)px/i.exec(style);
                                            var height = match && match[1];

                                            if (width) {
                                                element.attributes.style = element.attributes.style.replace(/(?:^|\s)width\s*:\s*(\d+)px;?/i, '');
                                                element.attributes.width = width;
                                            }

                                            if (height) {
                                                element.attributes.style = element.attributes.style.replace(/(?:^|\s)height\s*:\s*(\d+)px;?/i, '');
                                                element.attributes.height = height;
                                            }
                                        }
                                    }



                                    if (!element.attributes.style)
                                        delete element.attributes.style;

                                    return element;
                                }
                            }
                });
    });