Benjamin Li Benjamin Li - 1 month ago 22
React JSX Question

PropTypes in react + redux

in the redux examples, I can see something like this:

Footer.propTypes = {
completedCount: PropTypes.number.isRequired,
activeCount: PropTypes.number.isRequired,
filter: PropTypes.string.isRequired,
onClearCompleted: PropTypes.func.isRequired,
onShow: PropTypes.func.isRequired
}


so what are these PropTypes really doing? are they nice-to-have or must-have?

thanks

Answer

Great question! As pointed out by finalFreq I stand corrected! "the example provided will work perfectly fine in future versions of react. React deprecated calling the proptypes function directly but annotating a component will work just fine in current and future versions."

I suggest flowtypes (way more fun to use), (unlike typescript or proptypes), works at build time instead of run-time. This works in the editor! The editor extensions also use strong inference to alert you when a less obvious type is missing, null, or of a different type. The main benefit is that it speeds up development and reduces bugs without slowing run-time. You can easily strip the flow from your js before production.

FlowType: https://flowtype.org/docs/getting-started.html#_

To answer your question proptypes were never a must have and were at one point considered experimental. I loved them, but flowtype is more pragmatic IMHO.The main use is to prevent the misuse of a component by warning early on in development and offer coded documentation for better understanding(posterity).

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