如何查看 JavaScript / PHP 中的 2 段代码是否等效？

Question

I have some Ajaxing going on and I have 2 blocks of source code. The first is:

window.lastSavedContents = "<?php echo htmlentities( $contents ); ?>";

The second is whatever the user types into a text editor. The problem is window.lastSavedContents is htmlentities encoded, whereas the second block is not.

How can I check for equivalence?

Answer 1

First, don't use htmlentities , but htmlspecialchars , that only encodes < , > , & and " . That way, you can simply replace those entities using

var decoded = encoded.replace(/&/g, '&')
                     .replace(/&lt;/g, '<')
                     .replace(/&quot;/g, '"')
                     .replace(/&gt;/g, '>');

If you still want to use htmlentities you can simply create a temporary div :

var div = document.createElement('div');
div.innerHTML = encoded;
var decoded = div.firstChild.nodeValue;

Answer 2

You could either find a way around entity encoding the data, or decode window.lastSavedContents in Javascript. Here's a function that will help you do that: http://phpjs.org/functions/html_entity_decode:424