PHP: How to convert single quote to double quote in all HTML tags?

Question

How can I convert all single quotes to double quotes in all HTML tags only? Is there an easier way to do it? Thanks :)

For example: How can I convert this string (actual data from my work):

<TEXTFORMAT LEADING='2'><P ALIGN='LEFT'><FONT FACE='Verdana' style="font-size:10' COLOR='#0B333C'>My name's Mark</FONT></P></TEXTFORMAT>

To this:

<TEXTFORMAT LEADING="2"><P ALIGN="LEFT"><FONT FACE="Verdana" style="font-size:10" COLOR="#0B333C">My name's Mark</FONT></P></TEXTFORMAT>

Answer 1

If you don't care about the JavaScript and CSS issues mentioned elsewhere, try this:

$text = "<TEXTFORMAT LEADING='2'><P ALIGN='LEFT'><FONT FACE='Verdana' style='font-size:10' COLOR='#0B333C'>My name's Mark</FONT></P></TEXTFORMAT>";
echo preg_replace('/<([^<>]+)>/e', '"<" . str_replace("\\\\\'", \'"\', "$1") . ">"', $text);

This is taken from a thread by someone with exactly the same problem as you over at devshed.com.

Answer 2

I'm assuming that when you say in all html tags, that you mean all single quotes that contain an attribute. You wouldn't want <a onclick="alert('hi')"> converted b/c it would break the code.

Any regular expression is going to be fragile. If you know your input will be a particular set of simple cases, you might be ok with a regex. Otherwise, you'll want a DOM parser that understands complex html markup like onmouseover="(function () { document.getElementById(''); alert(\"...\")...})()" (for example). Add to that an attribute can span multiple lines. ;)

I haven't had to tackle this particular problem recently, but maybe there's a good way to do it with HTML Tidy (more here: http://devzone.zend.com/article/761) or a parser like this one http://sourceforge.net/projects/simplehtmldom/