Lifecycle Methods

The componentDidMount() method runs after the component output has been rendered to the DOM.

componentDidUpdate() is invoked immediately after updating occurs. This method is not called for the initial render.

componentWillUnmount() will be used if we need to 'cleanup' our page after something occurs.

Why we use lifecycle methods

render()

• we are ONLY going to return some JSX.
• will not be..
  • making a network request
  • making API request

componentDidMount()

• good for initial data loading
• getting something ONE TIME
• only gets invoked one time.
• is very similar to the constructor, however the docs do not support this. It is possible, but not recommended to do this in the constructor.
  • any initial loading should be done in the ComponentDidMount().

componentDidUpdate()

• called when any changes occur
  • state changes
• good for multiple data request

componentWillUnmount()

• used anytime we are about to remove a component after no longer need it on a screen.