Download media files only over wi-fi (possibly as an option)

[mcepl]

It would be really helpful if it was possible to limit download of potentially large multimedia files just for the wifi connection. Especially for Firefox OS many users will be on the metered Internet connection and downloads of multimegabyte files over 3G could incur substantial costs (and we don't have to go to the third world countries for this; it is so even here in the Czech republic).

[colinfrei]

I agree, last time I checked it wasn't possible to reliably check what type of connection was available. I'll have a look again if anything's changed.

[mcepl]

What about https://developer.mozilla.org/en-US/docs/Web/API/NetworkInformation.connection and https://developer.mozilla.org/en-US/docs/Web/API/Network_Information_API ?
Also http://www.sitepoint.com/use-network-information-api-improve-responsive-websites/