XHTML won't validate && and < in a JavaScript function

Question

Here's the snippet of code that won't validate:

if (user_age > 15 && user_age < 91)

It gets the following errors:

XML Parsing Error: StartTag: invalid element name

and

XML Parsing Error: xmlParseEntityRef: no name

The first error is thrown for the "less than" and the second one is thrown twice, once for each ampersand.

Replacing the above signs with & and < validates fine, but of course it completely ruins the function.

You could replace your expression by this one: `!(!(user_age > 15) || !(91 > user_age))`. But that’s just a workaround. — Gumbo, Oct 03 '09 at 14:34
PROBLEM IF Javascript was into a XML and XHTML is generated by XSLT: the CDATA ">", "<" and "&" are converted. alert((2>1)? 'OK1': 'OK2'); // is converted! Use — Peter Krauss, Sep 19 '11 at 10:27

score 40 · Accepted Answer · answered Oct 03 '09 at 14:33

40

Or you can protect the script from the xml validation like this:

<script type="text/javascript"> 
//<![CDATA[
    if (user_age > 15 && user_age < 91) {
        // do soemthing
    }
//]]>
</script>

answered Oct 03 '09 at 14:33

Joel Coehoorn

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protect from xml validation, that sounds like cheating in a test. Literal &<> must be inside CDATA in valid XML, without it, Firefox should refuse rendering the document if Firefox were conformant (but now the document is probably not served as `application/xhtml+xml` so it won't happen.) – u0b34a0f6ae Oct 03 '09 at 14:41

IProblemFactory · Answer 2 · 2009-10-03T14:37:25.627

8

Move script to other file :)

It is standard (and good) habit to separate style (into .css file), data (.html) and of course scripts to .js file.

edited Oct 03 '09 at 14:37

answered Oct 03 '09 at 14:31

IProblemFactory

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css should also be in it's own file – MrChrister Oct 03 '09 at 14:33

score 2 · Answer 3 · answered Oct 03 '09 at 14:33

2

All Javascript should be CDATA in XHTML:

<![CDATA[
if (user_age > 15 && user_age < 91)
]]>

answered Oct 03 '09 at 14:33

Martin

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Don't forget to comment it out as <![CDATA[]]> is an XML literal in JavaScript. – Eli Grey Oct 03 '09 at 20:39
1

Internet Explorer seems to conflict with this. For example, errors out when there are < symbols in Javascript code. – Jose Gómez Oct 25 '14 at 00:35

Xinus · Answer 4 · 2009-10-03T14:41:52.293

1

put javascript in <![CDATA[...]]> section

edited Oct 03 '09 at 14:41

answered Oct 03 '09 at 14:33

Xinus

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As stated in a reply to Martin's answer: Don't forget to comment it out as <![CDATA[]]> is an XML literal in JavaScript. – Eli Grey Oct 03 '09 at 20:40

score 0 · Answer 5 · answered Feb 12 '16 at 16:32

you can try CDATA but some time it wont work, it depends on the setting of the server I guess. I am not a pro, but i tested, and I did not work, but if you put the javascript code in the .js file and then link this file somewhere in your body. it will definitely work. PERSONALLY TESTED.

XHTML won't validate && and < in a JavaScript function

5 Answers5

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