javascript - Pasting into contentedittable results in random tag insertion

Question

I am using a contentedittable field as user input so that I can exploit text formatting. Unfortunately I have found that when a user pastes into the field a massive amound of unnessessary html comes with it. I only want the plain text from the clipboard.

Why is this happening?!

A Truncated Example:

<div><br></div><div><span class="Apple-style-span" style="font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 13px; line-height: 12px; color: rgb(0, 0, 0); "><table style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 13px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; border-collapse: collapse; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; background-position: initial initial; background-repeat: initial initial; "><tbody style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 13px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; background-position: initial initial; background-repeat: initial initial; "><tr style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 13px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; background-position: initial initial; background-repeat: initial initial; "><td class="votecell" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 13px; vertical-align: top; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; width: 60px; background-position: initial initial; background-repeat: initial initial; "><div class="vote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 13px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; text-align: center; background-position: initial initial; background-repeat: initial initial; "><span class="vote-count-post" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 31px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; display: block; color: rgb(128, 129, 133); font-weight: bold; background-position: initial initial; background-repeat: initial initial; ">1</span><a class="vote-down-off" title="This question does not show any research effort; it is unclear or not useful (click again to undo)" style="margin-top: 0px; margin-right: auto; margin-bottom: 0px; margin-left: auto; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 1px; vertical-align: baseline; background-image: url(http://sstatic.net/stackoverflow/img/sprites.png?v=3); background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; color: rgb(0, 119, 204); text-decoration: none; cursor: pointer; overflow-x: hidden; overflow-y: hidden; display: block; width: 41px; height: 25px; text-indent: -9999em; background-position: 0px -300px; background-repeat: no-repeat no-repeat; ">...

Answer 1

You can only get the plain text using a hack. Recent versions of both TinyMCE and CKEditor use this technique on their iframe-based editors:

1. Detect a Ctrl-v / Shift-Insert event using a keypress event handler
2. In that handler, save the current user selection, add a textarea element off-screen (say at left -1000px) to the document, turn contentEditable off and call focus() on the textarea, thus moving the caret and effectively redirecting the paste
3. Set a very brief timer (say 1 millisecond) in the event handler to call another function that stores the textarea value, removes the textarea from the document, turns contentEditable back on, restores the user selection and pastes the text in.

Note that this will only work for keyboard paste events and not pastes from the context or edit menus. The paste event would be better but by the time it fires, it's too late to redirect the caret into the textarea in most browsers.