On: Mozilla and Partners Prepare to Launch First Firef...

[karussell]

Could someone explain me how one can implement offline features like navigation etc for this phone? Is there an API besides HTML+JS?

[Yoric → karussell]

You can find everything here: https://developer.mozilla.org/en-US/docs/Web/Apps

[karussell → Yoric]

Thanks!

Hmmh, but all I see is WebApp, WebGL, JavaScript, HTML, ... I don't see 'native' -> How would I implement an offline navigation? (which is currently really not possible in JavaScript)

Or is it just not possible to create a resource intensive or tricky application in FireFox OS?

[csuwldcat → karussell]

"How would I implement an offline navigation? (which is currently really not possible in JavaScript)" - wow, just wow. Beyond the fact that this is just plain wrong - there are packaged apps that ship all assets on install, as well as great offline JS libraries - you do realize these things (offline, telephony, etc) are _APIs_ right? No _language_ Just Does™ offline or telephony - for instance, C++ is not somehow magically self-aware of internet connectivity, it's simply a language used by developers to code against device hardware/firmware which then provides _APIs_ for these capabilities.

JavaScript is no less capable of supporting these APIs, look at Node.js for instance, it has most of the server _APIs_ you find in other server implementations that use different languages as a base (and the Firefox platform has many of them already, with many more to on the way!)

[karussell → csuwldcat]

Yes, I was wrong: you can create offline navigation with JS! (sorry, for the incorrectness I really like JS, especially on the server!)

But you cannot - please correct me when I'm wrong - create offline navigation on a FireFox OS when using only the provided APIs. At least I don't see a way how it should scale beyond a smallish city.

[Yoric → karussell]

I'm not sure I understand where you see a limitation that could block you. See my other reply for a more elaborate discussion :)

[Yoric → karussell]

You don't need native to develop offline applications.

Perhaps this is what you're looking for: https://developer.mozilla.org/en-US/docs/HTML/Using_the_appl...

If you could provide examples of what you mean by "resource intensive" or "tricky", it might be easier to help you.

[karussell → Yoric]

How would you develop an application to do offline routing like my GraphHopper road routing project?

Such applications have to use the RAM or disc access provided by the OS. A simple cache will not do it. Although I could imagine that JavaScript is fast enough these days you still need access to lots of memory and load several hundred MB from somewhere/disc

[Yoric → karussell]

Interesting question.

Bulk loading/saving big binary data from/to IndexedDB is basically as fast as accessing the file system. Using TypedArray or (upcoming) BinaryData, JavaScript can also manipulate binary data pretty quickly.

I haven't attempted doing any serious graph processing in JavaScript, but these days, JavaScript is extremely fast at tree manipulation (much faster than OCaml, which has long been the fastest high-level language for this kind of thing), so I would imagine that it's quite suited for the task.

If you are serious about this, you should come and chat on irc.mozilla.org, channel #openwebapps for instance. We'll be happy to help you get started, plus that kind of discussion is often how new features and optimizations get started.

[doublec → karussell]

You could download the routing data into IndexedDB and use that for your file system.

[karussell → doublec]

And you know how fast that would be? Using an ordinary DB for graph algorithms is already slowish on a powerful server ...

[doublec → karussell]

IndexedDB allows direct access to the blobs like a file: https://developer.mozilla.org/en-US/docs/Web/API/FileReader

[karussell → doublec]

Intersting! (btw: this is only read only but useful)

[doublec → karussell]

There's a writable interface to IndexedDB files as well: https://developer.mozilla.org/en-US/docs/WebAPI/FileHandle

[wtetzner → karussell]

See here: https://wiki.mozilla.org/WebAPI

[karussell → wtetzner]

What parts are you meaning there? The USB access? How would I solve the graph processing problem I have in a typically navigation app? Loading the full graph from USB into RAM? Or traversing the graph on a slow USB stick?

I'm still not convinced. I can see the potential for games via WebGL + storage. But especially navigation software looks not really possible.