The Component Lifecycle - evan-401-advanced-javascript/seattle-javascript-401d31 GitHub Wiki

The component lifecycle tracks the day in the life of a component and can only be at one stage at a time. The first stage is mounting. This is when components are created and the constructor method is called. Once the constructor is completed the component enters the render phase leading to React mounting onto the DOM with the new component.

Stage 2 is updating and is triggered whenever the state or the props of the component are updated. Once updating is triggered the component goes through similar stages as before where it will again render followed by the React updating the DOM with the updated component.

All good things must end and sadly in the final stage of a components life it is unmounted. When our component is unmounted it will be removed from the DOM and any open connections must be cleaned up. This is the end of our component.