adds setText to text api.

[CrypticSwarm]

Closes issue #35
(#35)

Uses existing del and insert ops.

[josephg]

Ok to merge, @nornagon ?

[nornagon]

I'm happy with @CrypticSwarm's reasoning :)

[wmertens]

looks like this cannot be merged automatically any more?

[CrypticSwarm]

Most likely due to the generated compressed code. I should probably not have included those in the PR.

The fix would be to rebuild and accept the rebuilt version.

[wmertens]

Well, it still needs the unit test that Joseph wants too :-)

[wmertens]

I gave it a try with a test, and I had to add the same function to all the text APIs. That works for most but not for text-tp2.

Take a look at wmertens@6e84dc7

Any way to implement it better for text-tp2?

[wmertens]

@CrypticSwarm ping?

[CrypticSwarm]

Eeep. Not sure off hand. It is probably related to how tp2 works. I think tp2 leaves tombstones in place of deletes instead of deleting them. Perhaps that is making it fail.

[wmertens]

Escalating to @josephg :-) What do you think Joseph?

On Feb 28, 2013, at 21:08 , CrypticSwarm [email protected] wrote:

Eeep. Not sure off hand. It is probably related to how tp2 works. I think tp2 leaves tombstones in place of deletes instead of deleting them. Perhaps that is making it fail.

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[josephg]

This is a really roundabout way to replace the text contents, and it still has the bug @nornagon was talking about --- if the first submit fails, the error is discarded.

Why not just submit a single operation that deletes the entire document and inserts the string you want?

For the non composable text type, make an op that deletes everything then inserts text:

  setText: (text, callback) ->
    op = [{p:0, d:@snapshot.length}, {p:0, i:text}]
    @submitOp op, callback
    op

For composable text, do the same thing:

  setText: (text, callback) ->
    op = [{d:@snapshot.length}, text]
    @submitOp op, callback
    op

For TP2 its a little more complicated, because you need to delete all the characters, which have tombstones between them. Luckily, deleting a tombstone is a no-op so we can just delete everything.

  setText: (text, callback) ->
    op = [{d:@snapshot.totalLength}, {i:text}]
    @submitOp op, callback
    op

Interestingly, in the TP2 case you could swap the insert & delete and submit [{i:text}, {d:@snapshot.totalLength}] instead. The difference is that in the first case, everyone's cursors would teleport to the start of the document and in the second case they'd all float to the end.

There's a comment at the top of each OT type that tells you what operations look like. Take a look at the comment describing the TP2 type to understand a bit of whats going on there.

[josephg]

Also, this is missing tests.