React.js what is the "ctx" object and where does it come from?

Question

I have seen the dubious "ctx" object in React sometimes as a parameter, like in this _app.js: https://spectrum.chat/next-js/general/fetch-data-once-in-app-js~d76c5ea2-1a6f-4719-b476-a05765c726d1

and I am wondering what it exactly is and where does it come from, as I have seen no good documentation about what it is... is it the same as props passed to some react component?

Answer 1

ctx is a NextJS artifact. It is not part of standard React.

ctx is a context object containing those properties (Source):

• pathname - path section of URL
• query - query string section of URL parsed as an object
• asPath - String of the actual path (including the query) shows in the browser
• req - HTTP request object (server only)
• res - HTTP response object (server only)
• err - Error object if any error is encountered during the rendering

This may also help you.