URLSearchParams not defined error Inside A Function

Question

This is very odd, using DW CC 2018 (in case that is where the problem is), when i use URLSearchParams inside a script tag in my HTML page, it does not get flagged as an "error".

I put URLSearchParams in my external JS file, inside a function, it gets flagged as "not defined". DW flags it as an error, but it still works, so must be more of a "warning" than an error. This has me a bit concerned even if it is a warning, that it could break when going live.

Should I worry, or is it just once of those things to just ignore?

Answer 1

Dreamweaver probably uses an outdated list of "expected globals" in its indexer that isn't updated to include the URLSearchParams API, since it's relatively recent.

If you're not concerned with backwards compatibility *cough* IE *cough*, just add this somewhere in the offending file to get Dreamweaver to shut up:

const URLSearchParams = window.URLSearchParams;

If Dreamweaver doesn't support ES6 syntax (I've never used it), then you must add this somewhere that's not at the top level:

(function () {
  // must be in a closure
  var URLSearchParams = window.URLSearchParams;

  ...
})();

The reason why is because top-level var overwrites the global namespace in some browsers.