javascript - get custom attribute based on an id

Question

How can I find the seq number given the id in this example?

<table>
<tr class="row_header thin_border"> 
    </tr><tr id="id33192010101533333"  seq="2">
    <td>20101015</td>
    <td>600</td>
    <td>730</td>        
    <td><a href="#" onclick="deleteActivity(3319,20101015,1);">Click</a></td>
    <td><a href="#" onclick='selectEditActivity("id3319201010153333");'>Click</a></td>
    </tr>

    <tr id="id3319201010151111"  seq="3">
    <td>20101015</td>
    <td>600</td>
    <td>730</td>        
    <td><a href="#" onclick="deleteActivity(3319,20101015,1);"> <img src="/bbhtml/img/deleteAction.png"></a></td>
    <td><a href="#" onclick='selectEditActivity("id3319201010151111");'><img src="/bbhtml/img/editAction.png"></a></td>
    </tr>
<table>


<script>
    function selectEditActivity(pass_id){
        alert("seq# =:" + ???)
    }
</script>

Answer 1

try this

var id = document.getElementById("divId").getAttribute("attributeId");

Answer 2

How to get an attribute based on an id

With jQuery :

var seq = $('#id33192010101533333').attr("seq");

Without jQuery :

vvar seq = document.getElementById("id3319201010151111").getAttribute("seq");

You can try both of them at this Fiddle.

Both options should work in any browser!

---

What you really want

First of all, it's better to name your custom attribute data-seq instead of seq. The HTML5 standard allows custom elements but only considers them valid when their name starts with data-.

Also, it's not a good idea to put your click handlers directly in your CSS. It's better to use the class property or some custom data-action property with a value like edit or delete and then attach an event handler when you finish loading your page. Then, look at the first ancestor that has a data-seq property and get that property.

As one demo says more than a thousand words, here's a demo :

var list = document.querySelectorAll('[data-action="delete"]');
for (var i = 0; i < list.length; ++i) {
    list[i].addEventListener("click", function(e){
        alert('delete ' + e.target.closest('[data-seq]').getAttribute('data-seq'));
    });
}

var list = document.querySelectorAll('[data-action="edit"]');
for (var i = 0; i < list.length; ++i) {
    list[i].addEventListener("click", function(e){
        alert('edit ' + e.target.closest('[data-seq]').getAttribute('data-seq'));
    });
}

table, td {
    border : 1px solid #333;
}

td {
    padding : 10px;
}

<table>
    <tr class="row_header thin_border"></tr>
    <tr id="id33192010101533333" data-seq="2">
        <td>20101015</td>
        <td>600</td>
        <td>730</td>        
        <td><a href="#" data-action="delete">Click</a></td>
        <td><a href="#" data-action='edit'>Click</a></td>
    </tr>
    <tr id="id3319201010151111" data-seq="3">
        <td>20101015</td>
        <td>600</td>
        <td>730</td>        
        <td><a href="#" data-action="delete"> <img src="https://i.stack.imgur.com/mRsBv.png?s=64&g=1"></a></td>
        <td><a href="#" data-action='edit'><img src="https://i.stack.imgur.com/mRsBv.png?s=64&g=1"></a></td>
    </tr>
<table>

Or, if you prefer the jQuery way, you can replace the JavaScript code with the following (much simpler) code :

$('[data-action="delete"]').click(function(e){
    alert('delete ' + $(this).closest('[data-seq]').data('seq'));
});

$('[data-action="edit"]').click(function(e){
    alert('edit ' + $(this).closest('[data-seq]').data('seq'));
});

See also this Fiddle and this Fiddle for the same demo on JSFiddle, respectively without and with jQuery.

Answer 3

Retrieve the DOM element and then get the seq attribute:

document.getElementById(id).getAttribute('seq'); // note: this will return a string, and getElementById might return null in case there is no element with the given id.

Answer 4

You want to use objRef.getAttribute('seq') or plan old dot notation objRef.seq