Adding a checkbox to Link Dialog for more attributes : attributes not saved when looking at Source

Hello,

I want to add a checkbox in the Link box, when the writer precises an URL (so with the "protocol" list and "url" textbox). What would do the checkbox is simple: add the following attributes to the link:

class: "highslide" onclick="return hs.expand(this)"

So that I could give a highslide effect.

I followed this answer on StackOverFlow that was pretty helpful, so I did the same changes. I click to the Link Button, I add a Link and check my checkbox, I go into Source to check if the attributes are there: yes they are. Then, I go back in normal mode :

• if I click on "Source" again, some of my attributes have been removed;
• if I click on "Link" again, the box isn't checked;

I don't really know what to do at this point. Could somebody help me?

Maybe the StackOverflow reference is too old (one year) and there is a better example to follow?

Here are my changes:

In file plugins/link/dialogs/link.js (the only one modified) : http://pastebin.com/5wELVBAq for colors

around line 153: when loading target:

if ( element ) {
                /* HIGHSLIDE */
                var h = element.getAttribute( 'h' );
                retval.button = h;
                 
                var target = element.getAttribute( 'target' );

I used a "h" attribute, because I already add 2 attributes, and would like to check only 1 unique element.

around line 461: just before the definition of the browse button:

{/* HIGHSLIDE */
                    type: 'checkbox',
                    id: 'highslide',
                    label: 'Effet highslide pour zoomer sur l\'image ?',
                    setup: function(data){
                        this.allowOnChange = false ;
                         
                        if(data.button){
                            this.setValue(data.button);
                        }
                        this.allowOnChange = true;
                    },
                    commit: function(data){
                        data.button = this.getValue()
                        this.allowOnChange = false;
                    }
                
                },
               // block for that you could find using Ctrl+F on: id: 'browse',

around line 1096: inside onOk function:

this.commitContent( data );
            /* HIGHSLIDE */
            if(data.button){
                attributes["h"] = "true";
                attributes["class"] = 'highslide';
                attributes["onClick"] = 'hs.expand(this)';  
            }else{
                attributes["h"] = '';
                attributes["class"] = '';
                attributes["onClick"] = '';  
            }

The important attributes are class and onClick. I use h because I though this would help me get around that problem by checking only 1 attribute instead of the 2 others. Looks like I'm wrong on this one.