Contents
What is renderer in lightning component?
Renderer service in lightning component bundle modify the DOM elements which is created by framework for a component. We use custom renderer to change or override the default rendering behaviour of the component.
What is rendering in Salesforce lightning?
Each Lightning event triggers one or more actions that can update data. The updated data can fire more events. The rendering service tracks the stack of events that are fired. The framework rerenders all the components that own modified data by calling each component’s rerender() method.
What is renderer in Salesforce?
Render: – Is used to show/hide the particular block, output panel or input/output fields based on the condition. Example: – You have 2 fields one is visible and second is hidden, you want the second field to be visible when the first field is filled then use render.
How do you render in lightning component?
When a component is rendered or rerendered, the aura:valueRender event, also known as the render event, is fired. Handle this event to perform post-processing on the DOM or react to component rendering or rerendering. The event is preferred and easier to use than the alternative of creating a custom renderer.
What is LWC DOM?
Shadow DOM is a standard that encapsulates the internal document object model (DOM) structure of a web component. Since not all browsers that Salesforce supports implement Shadow DOM, LWC uses a shadow DOM polyfill. A polyfill is code that allows a feature to work in a web browser.
Why do we use shadow DOM?
Shadow DOM allows hidden DOM trees to be attached to elements in the regular DOM tree — this shadow DOM tree starts with a shadow root, underneath which can be attached to any elements you want, in the same way as the normal DOM. Shadow boundary: the place where the shadow DOM ends, and the regular DOM begins.
How does renderer service in Lightning component bundle work?
Renderer service in lightning component bundle modify the DOM elements which is created by framework for a component. We use custom renderer to change or override the default rendering behaviour of the component.
Do you need to create custom renderer for lightning aura?
The framework automatically renders your components so you don’t have to know anything more about rendering unless you need to customize the default rendering behavior for a component. It’s preferred and easier to handle the render event rather than the alternative of creating a custom renderer.
How does the unrender function work in Lightning?
It is triggered if anything is changed to the components just like button disable after clicked the button to show some results. If any component is not displayed due to aura:if condition is not satisfied or component is not displayed conditionally, at that point unrender () function of this component will be fired.
Can a lightning component update the DOM structure?
Yes, we can manage and update the pre-defined DOM Structure by Custom Rendering functionality provided by Lightning Component Framework in Salesforce. Salesforce Lightning Component Framework has provided us four phases of Rendering. To override the base render () function after component initialization.