jQuery DocumentFragment - JavaScript

DocumentFragment is a DOM object that represents a lightweight version of a document object. It is created with the createDocumentFragment() method and then can be used to hold DOM nodes temporarily before they are inserted into the actual document.

jQuery also has a documentFragment() method that creates a jQuery-wrapped document fragment. This allows developers to use jQuery methods to manipulate the document fragment.

Creating a Document Fragment

To create a document fragment, use the createDocumentFragment() method:

let fragment = document.createDocumentFragment();

jQuery offers a similar documentFragment() method:

let fragment = $("<div></div>").documentFragment();

Manipulating a Document Fragment

Once you have a document fragment, you can manipulate it just like any other DOM element. For example, to add a new element to the document fragment:

fragment.appendChild(document.createElement("div"));

To use jQuery methods, use the jQuery-wrapped document fragment:

$(fragment).append("<div></div>");

Benefits of Using Document Fragments

Using document fragments can improve code performance by reducing the number of DOM operations required. Instead of adding elements to the DOM one at a time, you can add them to a document fragment and then insert the entire fragment into the DOM all at once.

For example, consider the following code:

let parent = document.getElementById("parent");

for (let i = 0; i < 1000; i++) {
  let child = document.createElement("div");
  parent.appendChild(child);
}

This code adds 1000 child elements to the parent element one at a time, resulting in 1000 DOM operations. This can be slow, especially in older browsers.

With a document fragment, you can add all of the child elements at once:

let parent = document.getElementById("parent");
let fragment = document.createDocumentFragment();

for (let i = 0; i < 1000; i++) {
  let child = document.createElement("div");
  fragment.appendChild(child);
}

parent.appendChild(fragment);

This code creates a document fragment, adds 1000 child elements to it, and then inserts the entire fragment into the parent element. This results in only one DOM operation, which is much faster than the previous example.

Conclusion

Document fragments are a useful tool for manipulating the DOM in JavaScript. jQuery also offers a way to create and manipulate document fragments with its documentFragment() method. Using document fragments can improve code performance by reducing the number of DOM operations required.