How to know the possible HTML attributes of an element (EG ) in JS?

Question

How can I get to know a list of possible HTML attributes for a particular HTML node?

For example, when writing a userscript, I would like to know the possible HTML attributes of such nodes:

var images = d.getElementsByTagName('img');

something like: images[i].src

there is a way to do so. Look my updated answer ! – Sudarshan Tanwar May 30 '13 at 10:32 — Sudarshan Tanwar, May 30 '13 at 10:32

score 1 · Accepted Answer · answered May 30 '13 at 09:11

Browsers do not expose that information. You would need to get or create a machine readable specification for the markup language you are using.

HTML 4, for example, has DTDs that you could parse:

score 0 · Answer 2 · edited May 23 '17 at 12:23

0

Iterate over the properties of an object with for in like this:

var keys = [];
for (var key in obj) { 
  if (obj.hasOwnProperty(key) {
    keys.push(key);
  }
}

Or use Object.keys(obj) which will return an array of keys, but this will not work in older browsers – see compatibility table.

UPD. Misunderstood the question, for all possible values for DOM element you need to look at HTML DTDs as in Quentin's answer. It would still be possible to set arbitrary attributes though.

edited May 23 '17 at 12:23

Community

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answered May 30 '13 at 09:11

Misha Reyzlin

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possible attributes and set properties are not the same thing. – Quentin May 30 '13 at 09:15
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clearly communicated question and vaguely communicated question are also not the same thing – Misha Reyzlin May 30 '13 at 09:16

Sudarshan Tanwar · Answer 3 · 2013-05-30T10:27:03.477

-2

Try this Demo Here

var images = document.getElementsByTagName('img');
var allAttributes =Object.keys(image[0]);

edited May 30 '13 at 10:27

answered May 30 '13 at 09:20

Sudarshan Tanwar

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How to see a console window there? I also tried with Firebug but with no success. (Sorry but I haven't used it before). – Michał Tajchert May 30 '13 at 11:02
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press f12 in chrome and then see the right most label in the header. just click there.and u r in console. !! – Sudarshan Tanwar May 30 '13 at 12:15
or alternatively : http://stackoverflow.com/questions/66420/how-do-you-launch-the-javascript-debugger-in-google-chrome – Sudarshan Tanwar May 30 '13 at 12:17

How to know the possible HTML attributes of an element (EG ) in JS?

3 Answers3