Support saving files to the server

[TheBizzle]

I believe that this will also require user accounts and permissioning (since many people seem hesitant about making their work-in-progress models available to the public). Or maybe the initial draft of this should just upload all files into one central pool...?

We should also think about restrictions for what can and can't be uploaded. We don't really want people uploading any old thing they feel like putting on the server. What should the size limit be? Do we need to check that the file is a valid '.nlogo' file? Should we verify that the model passes the compiler before accepting it? (Probably not.)

[mrerrormessage]

Would it be acceptable to use localStorage instead? That would allow users to keep the file on their computer so that they didn't have to reopen it every time without making us liable for storage (and backup and security and authorization) of user data. We could even make something that shows users all the Tortoise files they've used up to this point, making switching between them really easy.

[qiemem]

I think localStorage plus "upload" and "download" buttons (that really just puts the file in the browser/takes it out of) to allow transferring files between computers would be sufficient, especially in the short term. localStorage is super easy to work with.

[TheBizzle]

That works for me.

[hirokiterashima]

Sounds great. Are you thinking about adding versioning support (undo, revert to point X, etc) at some point, or do you see this as something separate from the tool?

[TheBizzle]

It would definitely be good to have user file versioning at some point, but I think that can wait. And, fortunately, the Code tab that currently exists for Tortoise authoring already supports "undo" operations.

[SethTisue]

how about working with @reuven to keep the models on the Modeling Commons?

[qiemem]

Good idea @SethTisue.

I think we should have the localStorage thing in place no matter what, just as a convenience. It lets you do "starts up where left off" and such things easily.

[TheBizzle]

There are a lot of good long-term ideas here. I think that we would be wise to keep them in mind going forward, but, for now, what we need the most is a basic solution that allows people to save and open code that they wrote in Tortoise. Consequently, I've split the local storage stuff off into a separate ticket (#193) that should be given priority.