jquery gets binding method

In front-end development, we often need to use JavaScript frameworks to handle some complex interaction logic. Among them, jQuery is a widely used framework that provides a series of simple and fast APIs to operate DOM elements, handle events and other operations. When using jQuery to bind event handlers, you often need to obtain the bound handler functions. This article will introduce various ways to obtain jQuery event bindings.

1. Use data()

In jQuery, you can use the .data() method to get the data of the element. For example, we can bind an event handler to an element:

$("#myButton").on("click", function() {
  alert("Clicked!");
});

Now, we can use the data() method to get the bound event handler:

var clickHandler = $("#myButton").data("events").click[0].handler;

The above code obtains the first processing function bound to the click event through the data() method, which is the anonymous function defined above. It should be noted that this method is deprecated in jQuery version 3.x and later, and its use is not recommended.

2. Use $._data()

After jQuery version 3.x, we can use the $._data() method to obtain the bound data of the element . For example, we can modify the above code to:

$("#myButton").on("click", function() {
  alert("Clicked!");
});

var clickHandler = $._data($("#myButton")[0], "events").click[0].handler;

The above code obtains the first handler function bound to the click event through the $._data() method , which is the anonymous function defined above.

It should be noted that the $._data() method is an internal method and should not be used in formal projects. If you need to get the bound data of an element, you can use the more standardized data() method.

3. Use the event object

In the event processing function, we can obtain the bound event processing function through the event object. For example:

$("#myButton").on("click", function(event) {
  var clickHandler = event.handleObj.handler;
});

The above code obtains the event binding processing function through the event object. It should be noted that this method can only be used inside the event handler function.

4. Use unbind()

In jQuery, you can use the unbind() method to unbind the event of an element. When we need to obtain the bound event handling function, we can save the function to a variable before unbinding the event. For example:

var clickHandler;

$("#myButton").on("click", clickHandler = function() {
  alert("Clicked!");
});

$("#myButton").unbind("click", clickHandler);

The above code defines a clickHandler variable to save the event binding processing function. Then, we can use the unbind() method to unbind the event and obtain the bound event handling function before unbinding. It should be noted that this method only applies to a single event handling function.

Summary

This article introduces a variety of methods to obtain jQuery event binding processing functions, including using .data(), $._data(), event objects, and unbind() and other methods . It should be noted that after jQuery version 3.x, it is recommended to use the more standardized data() method to obtain the bound data of the element. When you need to unbind an event, you can use the unbind() method to obtain the bound event handler.

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