<?php
 
// START WITH THIS TEXT
$string = '<p style="font-size: 1.5em; color: navy;">
 Text With Spaces
<p style="font-size: 1.2em; color: navy;"> ';
 
// LOOK FOR AN OPENING TAG, FOLLOWED BY A SPACE AND
// - STRIP OUT ANY WHITESPACE AFTER IT
$string = preg_replace_callback('~<([A-Z]+) \K(.*?)>~i', function($m) {$replacement = preg_replace('~\s*~', '', $m[0]); return $replacement;}, $string);
 
print $string;
 
 
 
print "\n\n";
 
 
// HERE IS A MORE ADVANCED STRING WITH MULTIPLE SETS OF QUOTES AND OTHER TAGS THAT MAY NOT HAVE QUOTES
$string = '<p style="font-size: 1.5em; color: navy;"><a href="http://www.google.com" style="color: orange;">Google Website</a>
 Text With Spaces
<p style=\'font-size: 1.2em; color: navy;\'> <img src="http://www.google.com/images/logo.gif" width=100 height=100>';
 
// IF WE RUN THE SAME FUNCTION AS BEFORE, WE GET SOME MESSED UP TAGS
$string = preg_replace_callback('~<([A-Z]+) \K(.*?)>~i', function($m) {$replacement = preg_replace('~\s*~', '', $m[0]); return $replacement;}, $string);
 
print $string;
 
 
 
print "\n\n";
 
 
 
// LET'S TRY THIS AGAIN, BUT APPLY A LITTLE MORE LOGIC TO IT
$string = '<p style="font-size: 1.5em; color: navy;"><a href="http://www.google.com" style="color: orange;">Google Website</a>
 Text With Spaces
<p style=\'font-size: 1.2em; color: navy;\'> <img src="http://www.google.com/images/logo.gif" width=100 height=100>';
 
 
$string = preg_replace_callback('~<(.*?)>~i', 
 
    function($m) {
 
        $return_var = preg_replace_callback('~\'|".*?\'|"~', function ($r) {$v = preg_replace('~\s*~', '', $r[0]); return $v;}, $m[0]);
        return $return_var;
    }, 
 
    $string);
 
print $string;
 
 
// THAT SEEMS RIGHT

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