Javascript context menu click event/detection - filter paste content

I ran into this last year. In short, no.

I ended up using an onchange handler and filtering the content after it's already been pasted into the text box.

I would like to point out DOJO menu widget that is creating context menus perfectly in different browsers. http://www.dojotoolkit.org/reference-guide/dijit/Menu.html#dijit-menu

What you can do is that detect paste event in browsers that are supporting it and override context menu in browsers that are not supporting this event like opera.

Once you create your own context menu then you can add copy paste menu item or create context menu similar to the default using css.

Edited Some browsers might not allow us to fetch clipboard content, in this case we can always revert back to flash for borrowing some of its features that are cross browser. See couple of links I posted in comments.

Its complete implementation might have more issues than anticipated but it is possible and we can always give it a try (I will for sure).

You can intercept the paste with jQuery using the bind('paste', function() {});, compare string before and after pasting and apply your formatting.

The following was tested in IE7/FF3.6/Chrome/Safari 5

$("#textarea").bind('paste', function(e){ 
    // Do whatever you needed to do with the code here.
});

Live Example http://jsfiddle.net/VSrTg/2/

Edit An approach would be something like this:

$("#textarea").bind('paste', function(e){ 
    var oldText = this.value;
    setTimeout(function() { 
        // Compare oldText to $("#textarea").val() and format accordingly.
    }, 1000);
});

​Edit 2 Given your revisions to your original post, if you're worried about the giant market share that is Opera, you're going to have to monitor the value of your textbox with a setInterval() and compare it against itself for changes.

Ultimately there will always be a way around your script, even the above example is susceptible to simply dragging text from another text box (or the address bar) into it without triggering the paste event defined above.