Can I add a custom attribute to an HTML tag?

问题

Can I add a custom attribute to an HTML tag like the following?

<tag myAttri="myVal" />

回答1:

You can amend your !DOCTYPE declaration (i.e. DTD) to allow it, so that the [XML] document will still be valid:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"
[
  <!ATTLIST tag myAttri CDATA #IMPLIED>
]>

#IMPLIED means it is an optional attribute, or you could use #REQUIRED, etc.

More information is in DTD - Attributes.

回答2:

You can add custom attributes to your elements at will. But that will make your document invalid.

In HTML 5 you will have the opportunity to use custom data attributes prefixed with data-.

回答3:

No, this will break validation.

In HTML 5 you can/will be able to add custom attributes. Something like this:

<tag data-myAttri="myVal" />

回答4:

The jQuery data() function allows you to associate arbitrary data with DOM elements. Here's an example.

回答5:

In HTML5: yes: use the data- attribute.

 <ul>
  <li data-animal-type="bird">Owl</li>
  <li data-animal-type="fish">Salmon</li>
  <li data-animal-type="spider">Tarantula</li>
</ul>

回答6:

Yes, you can, you did it in the question itself: <html myAttri="myVal"/>.

回答7:

var demo = document.getElementById("demo")
console.log(demo.dataset.myvar)
// or
alert(demo.dataset.myvar)
//this will show in console the value of myvar

<div id="demo" data-myvar="foo">anything</div>

回答8:

You can set properties from JavaScript.

document.getElementById("foo").myAttri = "myVal"

回答9:

Yes, you can do it!

Having the next HTML tag:

<tag key="value"/>

We can access their attributes with JavaScript:

element.getAttribute('key'); // Getter
element.setAttribute('key', 'value'); // Setter

Element.setAttribute() put the attribute in the HTML tag if not exist. So, you dont need to declare it in the HTML code if you are going to set it with JavaScript.

key: could be any name you desire for the attribute, while is not already used for the current tag. value: it's always a string containing what you need.

回答10:

Here is the example:

document.getElementsByTagName("html").foo="bar"

Here is another example how to set custom attributes into body tag element:

document.getElementsByTagName('body')[0].dataset.attr1 = "foo";
document.getElementsByTagName('body')[0].dataset.attr2 = "bar";

Then read the attribute by:

attr1 = document.getElementsByTagName('body')[0].dataset.attr1
attr2 = document.getElementsByTagName('body')[0].dataset.attr2

You can test above code in Console in DevTools, e.g.

回答11:

use data-any , I use them a lot

<aside data-area="asidetop" data-type="responsive" class="top">

回答12:

Another approach, which is clean and will keep the document valid, is to concatenate the data you want into another tag e.g. id, then use split to take what you want when you want it.

<html>
<script>
  function demonstrate(){
    var x = document.getElementById("example data").querySelectorAll("input");
    console.log(x);
    for(i=0;i<x.length;i++){
      var line_to_illustrate = x[i].id  + ":" + document.getElementById ( x[i].id ).value;
      //concatenated values
      console.log("this is all together: " + line_to_illustrate); 
      //split values
      var split_line_to_illustrate = line_to_illustrate.split(":");
      for(j=0;j<split_line_to_illustrate.length;j++){
        console.log("item " + j+ " is: " + split_line_to_illustrate[j]);
      }      
    }
  }
</script> 

<body>

<div id="example data">
  <!-- consider the id values representing a 'from-to' relationship -->
  <input id="1:2" type="number" name="quantity" min="0" max="9" value="2">
  <input id="1:4" type="number" name="quantity" min="0" max="9" value="1">
  <input id="3:6" type="number" name="quantity" min="0" max="9" value="5">  
</div>

<input type="button" name="" id="?" value="show me" onclick="demonstrate()"/>

</body>
</html>

回答13:

You can add, but then you have to write a line of JavaScript code too,

document.createElement('tag');

to make sure everything fall in place. I mean Internet Explorer :)

回答14:

You can do something like this to extract the value you want from JavaScript instead of an attribute:

<a href='#' class='click'>
    <span style='display:none;'>value for JavaScript</span>some text
</a>

来源：https://stackoverflow.com/questions/1735230/can-i-add-a-custom-attribute-to-an-html-tag

标签

html

custom-attribute