Embedding XML in HTML

Question

How would one go about embedding XML in a HTML page?

I was thinking using CDDATA would be the best approach but I get errors in the HTML document when the page loads.

<script><![CDATA[ ... ]]></script>

I'm needing to embed a XML document for fetching later with JavaScript. I need to do this since when the user opens it, they might not have internet access.

CDATA is meant for embedding character data into XML, not embedding XML into HTML (HTML doesn't have such delimiters). — BoltClock, Oct 03 '12 at 15:47
As long as the XML doesn't contain `` anywhere, you should be able to just put it inside the script tags (with no CDATA section). Give the script a custom type so it doesn't get interpreted as JavaScript. — Dagg Nabbit, Oct 03 '12 at 15:48
This might be helpful: http://stackoverflow.com/questions/7816500/embed-xml-in-html-firefox-compatible — MikeB, Oct 03 '12 at 15:50
Ya, when I try to just drop it in the script tags I get: Uncaught SyntaxError: Unexpected token — amcdnl, Oct 03 '12 at 15:53
@AustinMcDaniel see my answer, it needs a `type` attribute other than "text/javascript" — Dagg Nabbit, Oct 03 '12 at 15:54
@GGG You are right, thanks. [No escaping is necessary](http://www.whatwg.org/specs/web-apps/current-work/multipage/scripting-1.html#restrictions-for-contents-of-script-elements) despite what these horribly, horribly, annoying Eclipse plugins have been telling me. — Ray Toal, Oct 03 '12 at 16:04
@RayToal not only is it not necessary, it won't work at all... in XML terms, you'd say `script` expects CDATA content, not PCDATA (not sure what the appropriate terminology is in HTML-speak). — Dagg Nabbit, Oct 03 '12 at 16:06
+1 Got it. In HTML 4 and earlier, `script` element bodies are CDATA, not PCDATA. In HTML 5 and up, they don't seem to show this distinction anymore, though they do allow `<![CDATA[` in foreign content (e.g. MathML or SVG). Script body content restrictions are now just described in prose. — Ray Toal, Oct 03 '12 at 16:20
@RayToal: in current HTML, `script` (along with `style`) is [acknowledged to be] a very special beast with syntax quite unlike anything seen in XML or SGML. I mean, the entire content is **allowed to be commented out** while still being used! That's pretty special. — SamB, Mar 18 '19 at 20:54

Dagg Nabbit · Accepted Answer · 2012-10-03T16:16:29.470

37

As long as the XML doesn't contain </script> anywhere, you can put it inside the script tags with a custom type attribute (and no CDATA section). Give the script tag an id attribute so you can fetch the content.

<script id="myxml" type="text/xmldata">
    <x>
        <y z="foo">

        </y>
    </x>
</script>

... 

<script> alert(document.getElementById('myxml').innerHTML); </script>

http://jsfiddle.net/hJuPs/

edited Oct 03 '12 at 16:16

answered Oct 03 '12 at 15:53

Dagg Nabbit

75,346
19
113
141

Setting type="text/xml" was the trick I was missing! Thanks! – amcdnl Oct 03 '12 at 15:58
1

@AustinMcDaniel note that it doesn't have to be "text/xml" ... it just has to *not* be "text/javascript" – Dagg Nabbit Oct 03 '12 at 16:00
3

And also note the type is "text/javascript" by default in HTML5 if omitted. – Kamiel Wanrooij Oct 03 '12 at 16:03
@AustinMcDaniel avoid the type `text/xml`! In the [spec](http://www.whatwg.org/specs/web-apps/current-work/multipage/scripting-1.html#scriptingLanguages) it lists "text/xml" as one of the MIME types that "must not be interpreted as scripting languages". However it also says that the `script` element is designed to store data blocks. Interesting. – Ray Toal Oct 03 '12 at 16:09
1

@RayToal ah, that's good to know. I wonder if `text/xml` gets special treatment in some implementations? I changed it to a custom mime type :) edit - but wait, isn't not being interpreted as a scripting language exactly what we want? I think it means `text/xml` is reserved for the sort of thing we're trying to do, no? – Dagg Nabbit Oct 03 '12 at 16:17

Kamiel Wanrooij · Answer 2 · 2012-10-03T16:00:27.913

0

How about:

<script>
    var xml = '<element> \
                 <childElement attr="value" /> \
               </element>';
</script>

That would enable you to easily embed the XML for later retrieval in javascript.

edited Oct 03 '12 at 16:00

answered Oct 03 '12 at 15:52

Kamiel Wanrooij

12,164
6
37
43

Chong Lip Phang · Answer 3 · 2014-09-17T05:52:30.690

0

According to the tutorial here, you can use the 'xml' tag to embed XML data within an HTML document. However, this implicitly displays the XML data in the browser.

http://www.expertrating.com/courseware/XMLCourse/XML-Embedding-HTML-8.asp

edited Sep 17 '14 at 05:52

answered Sep 17 '14 at 05:41

Chong Lip Phang

8,755
5
65
100

According to the link here, it has been deprecated. However, I have never seen this site before, nor have I had heard about the tag before seeing this stack question. http://www.html-5.com/changes/deprecated/xml-tag.html – jwp Nov 05 '15 at 18:43
1

XML is still widely used all over the world in nearly 9 out of 10 applications whether some web guy "didn't like it" and "json is better" (the actual real reason it was deprecated). I hope an alternative is provided for embeding XML or that's it's precated. – 1.21 gigawatts Dec 01 '18 at 00:50
@1.21gigawatts I doubt if that's the real reason the *element* was dropped. According to archived MDN page [Using XML Data Islands in Mozilla ](https://developer.mozilla.org/en-US/docs/Archive/Misc_top_level/Using_XML_Data_Islands_in_Mozilla), the feature was only ever supported in Internet Explorer, and Internet Explorer 10 *doesn't even support it anymore*. It seems pretty likely it never got used much use compared to the ` – SamB Mar 18 '19 at 21:13

Embedding XML in HTML

3 Answers3

Linked