How to Check if an Input Has Focus Using jQuery?

Using jQuery to Test if an Input Has Focus

This dilemma arises when using jQuery to replicate CSS :hover behavior for elements other than in IE6. The border surrounding the

disappears when an input within the form gains focus and the mouse cursor hovers in and out.

To address this, jQuery can be used to check if any input within the form has focus. However, as jQuery lacks a :focus selector, alternative methods must be employed.

jQuery 1.6

With jQuery 1.6 and above, a :focus selector is available. The following code can be used to check for focus:

$("..").is(":focus")

jQuery 1.5 and Below

For earlier jQuery versions, the following code can be used to define a new selector and check for focus:

jQuery.expr[':'].focus = function(elem) {
  return elem === document.activeElement && (elem.type || elem.href);
};

Alternatively, you can check which element has focus using:

$(document.activeElement)

For All jQuery Versions

To ensure compatibility with different jQuery versions, you can add the :focus selector as follows:

(function ($) {
  var filters = $.expr[":"];
  if (!filters.focus) {
    filters.focus = function(elem) {
      return elem === document.activeElement && (elem.type || elem.href);
    };
  }
})(jQuery);

By testing for focus, the border can be prevented from disappearing when an input gains focus and the cursor hovers in and out.

The above is the detailed content of How to Check if an Input Has Focus Using jQuery?. For more information, please follow other related articles on the PHP Chinese website!

jquery css define if for using this border input

Statement：

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn