- By default, setState triggers a re-renderThe default behavior of React is to re-render on every state change, and most of the time it is okay to rely on this.
- However, re-rendering unnecessarily wastes cycles which is not a good practice.Each component has a method called shouldComponentUpdate and it is called everytime you change state or pass new props from the parent component.
- We can simply divide lifecycle into three parts:Mounting: an instance of the component is being created and inserted into the DOM.Updating: component is being re-rendered, can be caused by changes of props or state.Unmounting: component is being removed from the DOM.It is very important to understand how these methods work….
- Compare this.props with nextProps and if there is a significant change, act on it.Two important notes here:React may call componentWillReceiveProps even if the props have not changed, so comparing this.props and nextProps is is invoked before a mounted component receives new props, this means React doesn’t call componentWillReceiveProps with initial…
- Use React Developer ToolsReact Developer Tools lets you inspect the React component hierarchy, components’ props and state.
At OpsGenie, we had a deep dive into React for our Badges project. I learned many new things & made many mistakes. These are the things that really helped me.
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