Escape quotes in JavaScript

Matt_Dawdy_232 0
Viewed 547058

I'm outputting values from a database (it isn't really open to public entry, but it is open to entry by a user at the company -- meaning, I'm not worried about XSS).

I'm trying to output a tag like this:

<a href="" onclick="DoEdit('DESCRIPTION');">Click Me</a>

DESCRIPTION is actually a value from the database that is something like this:

Prelim Assess "Mini" Report

I've tried replacing " with \", but no matter what I try, Firefox keeps chopping off my JavaScript call after the space after the word Assess, and it is causing all sorts of issues.

I must bemissing the obvious answer, but for the life of me I can't figure it out.

Anyone care to point out my idiocy?

Here is the entire HTML page (it will be an ASP.NET page eventually, but in order to solve this I took out everything else but the problem code)

<html>
    <body>
        <a href="#" onclick="DoEdit('Preliminary Assessment \"Mini\"'); return false;">edit</a>
    </body>
</html>
quotes escaping javascript
13 Answers

You need to escape the string you are writing out into DoEdit to scrub out the double-quote characters. They are causing the onclick HTML attribute to close prematurely.

Using the JavaScript escape character, \, isn't sufficient in the HTML context. You need to replace the double-quote with the proper XML entity representation, &quot;.

user_1948160 
<html>
    <body>
        <a href="#" onclick="DoEdit('Preliminary Assessment &quot;Mini&quot;'); return false;">edit</a>
    </body>
</html>

Should do the trick.

user_203770

The problem is that HTML doesn't recognize the escape character. You could work around that by using the single quotes for the HTML attribute and the double quotes for the onclick.

<a href="#" onclick='DoEdit("Preliminary Assessment \"Mini\""); return false;'>edit</a>
user_1169820

I have done a sample one using jQuery

var descr = 'test"inside"outside';
$(function(){
   $("#div1").append('<a href="#" onclick="DoEdit(descr);">Click Me</a>');       
});

function DoEdit(desc)
{
    alert ( desc );
}

And this works in Internet Explorer and Firefox.

user_477380

You can copy those two functions (listed below), and use them to escape/unescape all quotes and special characters. You don't have to use jQuery or any other library for this.

function escape(s) {
    return ('' + s)
        .replace(/\\/g, '\\\\')
        .replace(/\t/g, '\\t')
        .replace(/\n/g, '\\n')
        .replace(/\u00A0/g, '\\u00A0')
        .replace(/&/g, '\\x26')
        .replace(/'/g, '\\x27')
        .replace(/"/g, '\\x22')
        .replace(/</g, '\\x3C')
        .replace(/>/g, '\\x3E');
}

function unescape(s) {
    s = ('' + s)
       .replace(/\\x3E/g, '>')
       .replace(/\\x3C/g, '<')
       .replace(/\\x22/g, '"')
       .replace(/\\x27/g, "'")
       .replace(/\\x26/g, '&')
       .replace(/\\u00A0/g, '\u00A0')
       .replace(/\\n/g, '\n')
       .replace(/\\t/g, '\t');

    return s.replace(/\\\\/g, '\\');
}
user_103199880

Escape whitespace as well. It sounds to me like Firefox is assuming three arguments instead of one. &nbsp; is the non-breaking space character. Even if it's not the whole problem, it may still be a good idea.

user_2102450

You can use the escape() and unescape() jQuery methods. Like below,

Use escape(str); to escape the string and recover again using unescape(str_esc);.

user_15708930
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