html - how to get custom attribute of option tag in dropdown?

Question

If I have this code:

 <select onchange="alert('?');" name="myname" class="myclass"> 
    <option isred="-1" value="hi">click</option>
 </select>

How can I get the value '-1' from the custom attribute isred ? I don't want to use the value property. And I dont want to target the option tag by a name or id.

I want something like onchange="alert(this.getselectedoptionID.getAttribute('isred'));"

Can anyone help?

Also I don't want to use jquery.

Answer 1

You need to figure out what the selectedIndex is, then getAttribute from that options[] Array.

<select onchange="alert(this.options[this.selectedIndex].getAttribute('isred'));" name="myname" class="myclass"> 
    <option isred="-1" value="hi">click</option>
    <option isred="-5" value="hi">click</option>
</select>​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

jsFiddle DEMO

As a side note:

Don't use inline javascript in your HTML . You want to separate your business logic from your UI. Create a javascript event handlers instead to handle this. (jQuery / Angular / etc)

Answer 2

在jquery中，你可以写：

$("#myname").find(':selected').attr('isred');

Answer 3

Use something like this:

document.getElementById("x").onchange = function () {
    console.log(this.options[this.selectedIndex].getAttribute("isred"));
};

Answer 4

Assuming we have a HTML markup as below:

<form id="frm_">
    <select name="Veh">
        <option value='-1' selected='selected'>Select</option>
        <option value='0' ren='x'>xxx</option>
        <option value='1' ren='y'>yyy</option>
    </select>
</form>

The attr "ren" can be accessed like this:

function getRep() {
    var ren = document.forms['frm_'].elements['Veh'].options[document.forms['frm_']
                 .elements['Veh'].selectedIndex].getAttribute('ren');
    console.log("Val of ren " + ren); //x or y
}

Demo

Answer 5

You use: .getAttribute('isred')

You want:

<select onchange="alert(this.options[this.selectedIndex].getAttribute('isred'));" name="myname" class="myclass">
    <option isred="-1" value="hi">click</option>
    <option isred="-1" value="ho">click</option>
</select>

Answer 6

 //Pure Javascript solution, and elegant one check if you really want to leverage the power of javascript. // Listening to a onchange event by ID attached with the select tag. document.getElementById("name_your_id").onchange = function(event) { //event.target.selectedOptions[0] have that option. as this is single selection by dropdown. this will always be 0th index :) let get_val = event.target.selectedOptions[0].getAttribute("isred"); console.log("Value from the Attribute: ", get_val) } 

  <select id="name_your_id" name="myname" class="myclass"> <option isred="423423" value="hi">One</option> <option isred="-1" value="hi">Two</option> </select> 

Answer 7

您可以

$(".myclass").val(function(){alert($("option",this).attr("isred"));})