jQuery .closest()

.closest()

.closest( selector )Returns: jQuery

Description: For each element in the set, get the first element that matches the selector by testing the element itself and traversing up through its ancestors in the DOM tree.

• version added: 1.3.closest( selector )

  • selector
    Type: Selector
    A string containing a selector expression to match elements against.

• version added: 1.4.closest( selector [, context ] )

  • selector
    Type: Selector
    A string containing a selector expression to match elements against.
  • context
    Type: Element
    A DOM element within which a matching element may be found.

• version added: 1.6.closest( selection )

  • selection
    Type: jQuery
    A jQuery object to match elements against.

• version added: 1.6.closest( element )

  • element
    Type: Element
    An element to match elements against.

Given a jQuery object that represents a set of DOM elements, the .closest() method searches through these elements and their ancestors in the DOM tree and constructs a new jQuery object from the matching elements.

The .parents() and .closest() methods are similar in that they both traverse up the DOM tree.

The differences between the two, though subtle, are significant:

.closest()

Begins with the current element

Travels up the DOM tree until it finds a match for the supplied selector

The returned jQuery object contains zero or one element for each element in the original set, in document order

.parents()

Begins with the parent element

Travels up the DOM tree to the document's root element, adding each ancestor element to a temporary collection; it then filters that collection based on a selector if one is supplied

The returned jQuery object contains zero or more elements for each element in the original set, in reverse document order

 

<ul id="one" class="level-1">
  <li class="item-i">I</li>
  <li id="ii" class="item-ii">II
    <ul class="level-2">
      <li class="item-a">A</li>
      <li class="item-b">B
        <ul class="level-3">
          <li class="item-1">1</li>
          <li class="item-2">2</li>
          <li class="item-3">3</li>
        </ul>
      </li>
      <li class="item-c">C</li>
    </ul>
  </li>
  <li class="item-iii">III</li>
</ul>

 

Suppose we perform a search for <ul> elements starting at item A:

$( "li.item-a" )
  .closest( "ul" )
  .css( "background-color", "red" );

 

This will change the color of the level-2 <ul>, since it is the first encountered when traveling up the DOM tree.

Suppose we search for an <li> element instead:

$( "li.item-a" )
  .closest( "li" )
  .css( "background-color", "red" );

 

This will change the color of list item A. The .closest() method begins its search with the element itself before progressing up the DOM tree, and stops when item A matches the selector.

We can pass in a DOM element as the context within which to search for the closest element.

var listItemII = document.getElementById( "ii" );
$( "li.item-a" )
  .closest( "ul", listItemII )
  .css( "background-color", "red" );
$( "li.item-a" )
  .closest( "#one", listItemII )
  .css( "background-color", "green" );

 

This will change the color of the level-2 <ul>, because it is both the first <ul> ancestor of list item A and a descendant of list item II. It will not change the color of the level-1 <ul>, however, because it is not a descendant of list item II.

 

 

作者:Chuck Lu    GitHub