How to implement double-click modification in javascript

JavaScript is a programming language widely used in front-end development. Developers can use it to implement a variety of imaginative functions. One useful feature is to allow users to modify the content of an element on the page when they double-click on it. This feature is used in many applications, such as text editors or task managers. In this article, we will learn how to implement this functionality using JavaScript.

Add a double-click event

First, before we modify the content of the element, we need to add a double-click event to it. We can achieve it in the following way:

element.addEventListener('dblclick', function() {
  // 在这里编写事件处理逻辑
});

In the above code, we use the addEventListener method to add a double-click event, and the function associated with it will be executed when the user double-clicks the element. Now that our element has a double-click event, the next step is to modify its content in the double-click event.

Modify element content

After we determine the element to add the event, the next step is to modify the content of the element in the double-click event. We can use the innerHTML attribute to get and set the content of the element.

element.addEventListener('dblclick', function() {
  var currentContent = element.innerHTML;
  element.innerHTML = '替换内容';
});

In the above code, we first use the innerHTML attribute to get the current content of the element and store it in the variable currentContent. We then set the element's content directly to a new string, thus changing its display text.

Implement double-click modification

Now, we have implemented the basic double-click event and the code to modify the content of the element. However, there are several issues with this implementation that need to be addressed further. For example, we need to ensure that only a single element is editable at any one time, and that elements cannot be double-clicked to select or dragged. In order to solve these problems, we need to extend the code:

var currentEditable = null;

function makeEditable(element) {
  element.setAttribute('contenteditable', 'true');
  element.focus();
  currentEditable = element;
}

function makeNonEditable() {
  if (currentEditable) {
    currentEditable.setAttribute('contenteditable', 'false');
    currentEditable = null;
  }
}

document.addEventListener('click', function(event) {
  if (!event.target.isContentEditable) {
    makeNonEditable();
  }
});

document.addEventListener('keydown', function(event) {
  if (event.keyCode === 13) {
    makeNonEditable();
  }
});

element.addEventListener('dblclick', function(event) {
  event.preventDefault();
  makeNonEditable();

  if (event.target.isContentEditable) {
    return;
  }

  makeEditable(event.target);
});

This implementation includes the following steps:

1. We define a global variable currentEditable To track the element currently in the editing state, if no element is in the editing state, the variable is null.
2. We define two auxiliary functions makeEditable and makeNonEditable, which are used to convert elements to editable state. When the page is not editable, clicking anywhere on the page will stop editing.

3. We added two event listeners:

   • click The listener is used to detect mouse click events. If the target element of the click event is not editable, we transition all elements from editing state to non-editing state.
   • keydown The listener is used to detect key events. If the user presses the Enter key, all elements transition from editing to non-editing state.
4. We added a dblclick listener, which is used to detect the user's double-click event. If the user double-clicks a non-editable element, the element will be converted to an editable state.

Now, we can use the above code to implement double-click editing of text.

Summary

In this article, we used JavaScript to write code that double-clicks to modify the content of an element. We use the addEventListener method to add a double-click event to the element, in which the innerHTML attribute is used to modify the content of the element. Finally, we also added other processing, such as controlling only one element to be editable. These implementations help improve the usability and user experience of your application, and we hope they can be helpful to your development work.

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