Back in April '06 I talked about the bug in Domino whereby it inserts "random paragraph breaks". When using one of the many WYSIWYG HTML editors to edit documents there was a potential problem in that Domino could insert its own carriage returns at any point in your HTML. If this happens to be inside an HTML tag then you're likely to get some garbled, badly-formatted output.

The solution at the time seemed to be an upgrade to 6.5.5. It worked for me and I've not suffered the same problem since. Until yesterday that is. This time the server was 7.0.2 and the same "regression bug" appears to be back. Although I'm not 100% certain it's the exact same bug it's still a problem and so a solution is needed regardless of what the actual cause is.

In my case the editor in question was TinyMCE and the problem was Domino breaking the HTML in the wrong place. The trouble seems to be that TinyMCE sends the whole of the HTML you've written to the server as one long unbroken string. Domino doesn't like this and so breaks it in to chunks after every 16,000th character or so.

To stop this happening we need to stop TinyMCE sending one long line of text and break it up in a sensible manner before Domino gets the chance to.

The solution was suggested in the comments to that original post by, amongst others, Patrick Niland. His idea was to use the save_callback method of the editor to alter the HTML before it gets posted. The solution is worthy of its own posting instead of being hidden in the comments back there.

Here's an example of the JavaScript needed on a form that uses the editor and demonstrates how you can use regular expressions to split the HTML:

tinyMCE.init({
        mode: "exact",
        elements: "Body",
        //Lots of other options here
        save_callback: "addNewLinesForDomino"
})

function addNewLinesForDomino(element_id, html, body){
        return html.replace(/(\<\/(div|h[1-6]{1}|p|ol|ul|pre)\>)/gi, "$1\n");
}

What this does is tell the TinyMCE editor to call the function "addNewLinesForDomino" before the form is submitted to the server. When the function runs it adds a new line after all the common block-level elements that might appear in the HTML. Not only does this prevent problems at the server it also lends itself to much tidier looking code in the source.

If nothing else it's a nice example of the power of Regular Expressions. Does that part make sense? Hands up if not and I'll explain.

If you use TinyMCE with Domino add this fix now.