React Server Side rendering is rerendered in frontend?

Question

in this isomorphic example https://github.com/DavidWells/isomorphic-react-example he shows Server Side Rendering by disabling Javascript. But if javascript IS enabled in frontend, is it rendered again?

I did a small test by putting a console.log in the render function and it logs in the NodeJS console but also in the browser's console.

Is react intelligent enough to not rerender if the HTML comes from the server?

Answer 1

It will render again in the sense that all of the React Component render functions will run again. It will not necessarily change the DOM at all however because React's diffing algorithm will not do anything if the correct DOM nodes are already in the page.