views:

393

answers:

6

Is is possible to use jQuery to select an ancestor of an element?

Markup:

<div id="ancestor-1">
    <div>
        <a href="#" class="click-me">Click me</a>
    </div>
</div>
<div id="ancestor-2">
    <div>
        <a href="#" class="click-me">Click me</a>
    </div>
</div>

Script:

$(".click-me").click(function(){
    // var ancestorId = ???;
    alert(ancestorId)
});
A: 

Are you looking for parent()? jQuery Doc for parent selector. If it is different for your scenario explain what is your expected output.

Teja Kantamneni
+2  A: 

You mean something like this?

$('.click-me').click(function() {
    var $theAncestor = $(this).closest('#ancestor-1');
}

This will search through all ancestors until a match is found.

http://api.jquery.com/closest/

EDIT:

Jerome, your question can be interpreted several ways. This speaks to the power and flexibility of jQuery.

Please consider the following.

First, to answer your question, yes, it is possible to use jQuery to select an ancestor of an element.

I think we can assume that you are aware of jQuery's ability to select any element, whether ancestor or descendant via:

$('#myElement')

Given the click-me example, if you would like to have a set of all of an element's ancestors returned, use:

$(this).parents()

or

$(this).parents(selector)

But be aware that this will traverse through ALL ancestors returning all, or all that match when a selector is given.

If you would like to have the immediate parent returned, use:

$(this).parent()

If you know which ancestor you need, use:

$(this).closest(selector)

But be aware that it will only return the first match, and if the current element (this) is a match, it will return that.

I hope this helps.

patrick dw
The difference between `parents()` and `closest()` is subtle but important. `closest()` will return the current element if it's a match; `parents()` returns _only ancestors_. You many not want the possibility of returning the current element. `closest()` also only returns one element; `parents()` returns all matching elements.
Ryan McGeary
@Ryan - My answer was specific to the question. The question suggests a query for a specific ancestorID, rather than a general query about what the parents are. Given the incrementing nature of the ancestor ids, it seems as though jerome may intend to calculate the ancestor id from the context and request that.
patrick dw
Patrick, If Jerome intended to calculate the ancestor id from the context, **there's absolutely no point** in using `$(this).closest('#ancestor-1')` when `$('#ancestor-1')` would not only suffice but also be faster. Sometimes, it's better to read into the intentions of a question and direct the answer accordingly.
Ryan McGeary
@Ryan - Respectfully, the point is that he appears to be searching for something **specific** that is **expected** to be an ancestor. His exact question was "Is is possible to use jQuery to select an ancestor of an element?". Not "Is is possible to use jQuery to return all ancestors?". You said - "Sometimes, it's better to read into the intentions of a question and direct the answer accordingly." And yet your quibble with 'closest()' is that it can return one element including the current element. Reading into Jerome's intention tells us that he is selecting a **unique and specific ancestor**.
patrick dw
-1 He wants the closest ancestor’s ID and not the ancestor with a specific ID.
Gumbo
@Ryan - Regarding using $('#ancestor-1'), that is obvious. I was merely using his example criteria. In that case, neither closest() nor parents() is appropriate. The question was a little vague and the example not perfectly formed, hence the friction.
patrick dw
@Gumbo, his code example somewhat appears that way, but his question suggests that he want's the element. His var ancestorID makes me think that he was simply storing that ID, then using ancestorID to grab the element. I may be wrong. It's just not entirely clear.
patrick dw
@patrick: Sorry, but selecting the element with the ID *ancestor-1* is absolutely trivial. I don’t think he’s really asking for that.
Gumbo
@Gumbo, you're right. It is trivial. See my previous comment. He doesn't state that he wants the ID, but he does state that he wants to select the ancestor. He just doesn't clarify exactly how he will specify which ancestor he wants. If he does indeed want the closest ancestor that has an id, then closest() is still best. See tvanfosson's answer. The intention of the question seems clear. The code obfuscates that intention.
patrick dw
By the way, as far as we know, he may have just been curious about jQuery's ability to grab an ancestor. The code example may have just been a quick mockup to illustrate his question. Either way, we know he wants to grab an ancestor, and obviously he's looking for a way other than the expected $(selector) method.
patrick dw
Just to clarify, my original "quibble" about the different between parents and closest wasn't a quibble. It was meant to be educational to future readers of this thread. Depending on the intention of the reader, `closest()` may not have the desired effect. It is a viable way to achieve the result though. `parents()` might not have the desired effect either; hence the clarification.
Ryan McGeary
With respect, please read your first comment from this thread. You said *"closest() will return the current element if it's a match"*. I called this a quibble because it is not relevant to a question regarding selection of **a unique ancestor**. It is a worthy educational point, but not a valid criticism of my solution *considering the question*. Were it not explicit that what was being selected was very definitely an ancestor of the current object, then I would be in agreement with your criticism. My apologies if I offended you.
patrick dw
A: 

Try parent() for the immediate parent element.

$(".click-me").click(function() {
  var ancestor = $(this).parent();
  alert(ancestor)
});

Or parents() for all matching ancestor elements.

$(".click-me").click(function() {
  var ancestors = $(this).parents(".some-ancestor");
  alert(ancestors)
});

Or closest() for the first closest matching element (either an ancestor or self).

$(".click-me").click(function() {
  var ancestor = $(this).closest(".some-ancestor");
  alert(ancestor)
});

The difference between parents() and closest() is subtle but important. closest() will return the current element if it's a match; parents() returns only ancestors. You many not want the possibility of returning the current element. closest() also only returns one element; parents() returns all matching elements.

Ryan McGeary
A: 

http://api.jquery.com/parent/ and http://api.jquery.com/parents/

$(".click-me").click(function(){
    var ancestorId = $(this).parent().parent();
    alert(ancestorId)
});

would return the divs with the ids

harpax
+1  A: 

Try using parents() or closest() in combination, perhaps, with a selector to determine which ancestor should match. For example, find the closest ancestor div with an id.

$('.click-me').click( function() {
      var ancestorId = $(this).closest('div[id]');
      alert(ancestorId);
});
tvanfosson
A: 

It really depends what you want to achieve. Do you want to search for all ancestors regardless of class used? Or do you want to search for all elements that are ancestors and have certain class (ancestor-x in your case)?

If you want to cycle through any ancestors, simply use .parent() (there's an excellent example how to cycle through all elements) or .parents() which can you use like:

$(".click-me").click(function(){
    var parentElements = $(this).parents().map(function () {
        return this.tagName;
    })
    // whatever else you want to do with it
});

Probably the best approach would be to use .parents() until you get to element with certain id or class. It really depends on what you want to do.

Ondrej Slinták