Dynamically creating a regular expression

[Fmdpa]

I'm stumped on how to create a regex dynamically. I can't use "+" to concatenate a variable onto the regex because "+" is a metacharacter within a regex. And, to my knowledge, I can't terminate a regex like you can with a string by closing a quote. Is it possible?

[jeffman]

Pass a string to the RegExp constructor, and you can do exactly what you're asking: http://www.w3schools.com/jsref/jsref_obj_regexp.asp . It's not very intuitive if you're used to normal regex, so play with it.

[Fmdpa]

Perfect, thanks!

[Fmdpa]

Now I've got another problem with the JS replace() function. I want to replace the matched text (with the regex in the first arg) with the text surrounded by a set of tags. e.g.

regex = new RegExp('(' + whitelist.join('|') + ')', 'ig');thisNode.nodeValue = thisNode.nodeValue.replace(regex, function(replaced) {														   '<b>' + replaced + '</b>'														 });

Of course, this replaces doesn't actually create an element node. How could I do that?

[jeffman]

node.cloneNodedocument.createElement?

[Fmdpa]

Is there a way to surround matched text with tags? If I create the element, I don't know where to append it unless I get the position of the match (in the .replace() call).

[Fmdpa]

JSYK, I'm using this only for a new browser so I don't have to worry about old JS incompatibility issues. I know you are quite familiar with JS methods so if you know of one that might do what I'm needing to do (even if it isn't supported in older browsers), I would love to hear about it. I'm beginning to think the solution might not even include the replace() method...

[jeffman]

Try this:

function func () {	var el = document.getElementById("myElement");	var myClone = el.cloneNode(true);	var b = document.createElement('b');	b.appendChild(myClone);	el.parentNode.replaceChild(b, el);}

[Fmdpa]

I think there was a misunderstanding (not that I don't appreciate your help!). Here's what I want to do:

"<b>the <i>text</i> value of this b element node</b>" // search for 'value' with the regex [b]/value/i[/b]. If it is found, wrap it in <u> tags =>"<b>the <i>text</i> <u>value</u> of this b element node</b>"

I have a feeling the solution may utilize the search(), substr(), match(), cloneNode(), replaceChild(), createElement(), createTextNode() methods and possibly others.

[Fmdpa]

Aha: this may be the solution https://developer.mozilla.org/En/DOM/Text.splitText