The ability to track DOM tree modifications is provided via the MutationObserver interface. It is intended to take the place of the previous Mutation Events functionality, which was included in the DOM3 Events definition.
The DOM can often change in complex web projects. Because of this, there are times when your app may need to react to a particular modification to the DOM. Listening to DOM changes is possible via the MutationObserver interface.
Config is an object with parameters defining the changes to respond to and is returned by the function.
The callback follows any modifications. The observer becomes the second object, and the modifications are passed on to the first argument as a list of MutationRecord objects.
To use the MutationObserver API, you must first:
let observer = new MutationObserver(callback);
There are two parameters in the observe() function. The target is the root of the node subtree that needs to be watched for changes. What DOM changes should be communicated to the observer's callback are specified by the parameters in the observerOptions parameter.
Insert the characters in the input field
After inserting the characters
You can define options to characterize the MutationObserver by passing them as the second argument to the observe() method:
Not every choice has to be chosen. However, at minimum, one childList, attributes, or characterData must be set to true for the MutationObserver to function; otherwise, the observer() method will return an error.
The following properties are included in the MutationRecord object:
Observe the changes in a child element
The mutation method can show the child element start, stop, add, and remove functionality. The following steps help to show changes in the child element of the function.
Use the mutation function and callback with the variable
The following examples show the child list and its data with different operations.
The example shows the basic changes in the child element of the parent element.
Click start button
Click stop button
The example shows the insert data in the child element of the parent element.
Before inserting the last element
After inserting the last element
The example shows the deleted data in the child element of the parent element.
The given image shows the output of the deleted last value of the list.
Before removing the last element
After removing the last element
Keep in mind the mutationObserver crucial details.