importScripts

[tgvashworth]

• Synchronous loading
• Variable assignment

Implementation options:

• Make importScripts do horrible things with Node to get 'sync' network call
• Return result directly from importScripts

or

• Parse/AST the worker, pull out the import URLs and load them at the install phase.
• Then make the importScripts method just key a URL -> result map.

Second one for me.

[jakearchibald]

The first implementation sounds like the best thing. However, importScripts should throw if it's called after the initial execution of worker.

importScripts shouldn't make a network request once the serviceworker has installed, imported scripts should be put in a special cache.

Related: https://github.com/slightlyoff/ServiceWorker/issues/106

[tgvashworth]

Seems like the best method here would be a combination of both:

• Parse the worker to find all importScripts URLs
• Fetch the contents of those files
• Replace importScripts instance with this code before new Function-ing the worker

[tgvashworth]

But, this isn't such a great method if you want to prevent it being called later.

[jakearchibald]

The parsing trick falls over with importScripts(variable).

What's the benefit of calling importScripts later than initial execution?

[tgvashworth]

Not sure what you mean – you can get the variable out no problem.

The problem with not doing an AST parse is that, afaik, there's no way to pause function execution while node does a network request and have the fetched code execute in the same scope as the worker.

[jakearchibald]

Not sure what you mean – you can get the variable out no problem.

var whatever = 'foo';

if (version > 4) {
  whatever = 'bar';
}

importScripts(whatever);

or

importScripts(whatever + Math.random());

The problem with not doing an AST parse is that, afaik, there's no way to pause function execution while node does a network request and have the fetched code execute in the same scope as the worker.

Oh, there isn't a way to make a sync network request? Sheeeeet

[jakearchibald]

You're not going to like it, but here's how the xmlhttprequest lib does sync requests https://github.com/driverdan/node-XMLHttpRequest/blob/master/lib/XMLHttpRequest.js#L454

[tgvashworth]

Eurgh, yeah. Fair enough. @ahume's working on this atm.

[ahume]

Think this is more or less there. Reopen if not.