What does save and save! method do?

[kapso]

I am new to RubyMotion/MotionModel and was looking at different persistence options.
I came across this issue #12 and this recommends calling serialize/deserialize explicitly.

If thats the case then what does method save & save! do?

[sxross]

Because the ArrayModelAdapter is moving stuff around in volatile memory, you do have to explicitly call the persistence methods to store the data in nonvolatile memory. This was an implementation decision that may seem jarring if you are used to Rails and discrete saves to NV storage. In our case, I didn't want to presume anything that might negatively impact performance.

Does this help explain?

[kapso]

As a newbie its confusing for sure, it took me a while to realize that save is not actually "saving". May be adding a note to save documentation would help. Also may be a design change where serialization is provided out of the box (but made optional) would help.

[sxross]

There is an example under notifications that should give you a good idea how to make save mean save. But point taken about the README. If you want to take a crack at it and submit a pull request, that would be great.

[kapso]

Ok I will take a look. Also what does MotionModel::ArrayModelAdapter provide? Do I need that?

[sxross]

There are two branches. Master requires you include the ArrayModelAdapter. The SQL branch uses FMDB and the SQLite database. You should look at the example and docs in the SQL branch if you want to use that.

To answer your question, ArrayModelAdapter provides finder, persistence etc. specific to the backing store.

[kapso]

So does that mean delete_all and destroy_all remove the data from memory only? at least thats what I am seeing. This is all very confusing :)