What is connected callback vs. rendered callback in the lightning web component?
Salesforce LWC is a vast topic. That is why I am finding that understanding the LWC component lifecycle methods is crucial and difficult. Can anyone help me understand what connected callback and rendered callback are?
The connected callback vs. rendered callback is essential to understand the Salesforce LWC. You need to understand the difference between the two. Firstly, the connected callback is executed when it is provided to DOM. The connected callback () hook can be executed more than once. For example, when you reorder a list, it gets fired multiple times. Also, if you want it to stop being executed more than once, you need to write to code.
On the other hand, when rendered, callback is invoked when the elements on the component are provided. One of the best examples of rendered callback is that it is used to load static resources.
Answer (1)
In the context of Lightning Web Components (LWC) in Salesforce, both Connected Callback and Rendered Callback are lifecycle hooks that allow you to perform actions at specific points in a component's lifecycle.
Connected Callback: This is invoked when a component is inserted into the DOM (Document Object Model). It runs after the component is connected to the document and after its child elements are connected. This is typically where you perform initialization tasks that require DOM access. For example, you might fetch data from a server or set up event listeners.
Rendered Callback: This is invoked after the component's template has been rendered and after any new child components have been rendered. It's called every time the component is rendered, whether initially or due to re-renders caused by data changes or other reasons. This is useful for performing actions that require access to the component's rendered DOM elements, such as manipulating the DOM directly or interacting with third-party libraries that require rendered elements.
In summary, Connected Callback is called once when the component is inserted into the DOM, while Rendered Callback is called every time the component is rendered, allowing you to perform tasks at different stages of the component lifecycle.