Fail more gracefully on unsupported browsers

[jkomoros]

Polymer only works on modern browsers. Currently if you use a browser that's not supported, the app will fail in various, sometimes non-obvious ways.

In an ideal world we'd do something more reasonable like detect if you're on an unsupported browser and show a dialog that says something like "Polymer only works on modern browsers. Your browser is not fully supported and this application might not work." There should also be a button to "try anyway". It's not ideal, but it's better than what we have now.

I consider this a blocker to hosting Sandbox for people to play around without a checkout.

[jkomoros]

Feature detecting all of the things we rely on is probably too hard to do reliably. I see this as a temporary feature. Even just having some kind of (gasp!) whitelist for supported browsers, early in the bootsrapping process.

The text can say something like "Polymer is a pre-alpha framework that targets modern browsers. We haven't tested in your browser yet, so things might not work." With a "Try Anyway" button.

[Garbee]

Could we work with the modernizr project to build feature detection for what Polymer requires into their code? If so then we could build detection there and just use that for displaying whatever we want.

@paulirish Do you think this is something inside of Modernizr's scope?

[jkomoros]

It'll probably be very hard to even know what features to detect, let alone to figure out the way to detect them. Ideally we'd get to that at some point, but probably not for a long time.

The idea behind this issue was more a quick-and-dirty stopgap.

[Garbee]

Yea, if we aren't interested in doing a long-term solution at the moment, then a quick whitelist is the most efficient way I'd think.

[dfreedm]

Related: Polymer/platform#25

[singhalpriyank]

The issue has been resolved by @azakus using a quick and dirty whitelist for supported browsers. Other clients will get a dialog box with a message that some things may not work.

Feature should be available at next stable push.

[oleersoy]

Is there an API we can use to augment this feature? More specifically:
http://stackoverflow.com/questions/30666587/detect-browser-support-fo-polymer

TIA,

• Ole

[gusdecool]

@singhalpriyank how @azakus resolve this issue? any example?