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Re: On Contractor and Luna


Status update!

Victor has designed and (together with Akhay) implemented a more
object-oriented API for Granite:

He has also updated Files to make use of it:

I've already verified that Granite and Files parts work as expected.
I've also the Contractor rewrite for landing to PPA, so the moment the
merge requests are approved we can finally land all this awesome work.

2013/4/14 Sergey "Shnatsel" Davidoff <sergey@xxxxxxxxxxxxxxxx>:
> Thanks! Could you write what you want to see changed in the API to make it
> easier to use on the merge request?
> 2013/4/14 Victor <victoreduardm@xxxxxxxxx>
>> Awesome work on Contractor!
>> As for the Granite wrapper, I don't really see a lot of value in it since
>> it's still a string-based API similar to the one we had before. It doesn't
>> exploit Vala's object capabilities either. Is it really too much to ask to
>> request OO APIs for Granite?
>> Vala is object-oriented. Structured designs will most of the time produce
>> bad client code in such languages.
>> If you are proposing a new API for Granite and breaking an old one, make
>> it worth it. Keep in mind that after Luna is released API breaks will be
>> more difficult to handle, and ABI breaks forbidden.
>> On Sun, Apr 14, 2013 at 1:10 AM, Sergey Shnatsel Davidoff
>> <sergey@xxxxxxxxxxxxxxxx> wrote:
>> Hey guys,
>> We have a lot of progress to report! Thanks to Michael Lazarski, Akshay
>> Shekher and Tom Beckmann we now have a working implementation of Contractor
>> daemon using the new API. It's already much less buggy than the older one.
>> Akshay has also transitioned Granite's wrapper to Contractor D-bus API to
>> the new API, it just needs one final round of review:
>> https://code.launchpad.net/~voldyman/granite/contractor-wid-dep-new-Contractor/+merge/158161
>> As soon as that's merged I'll land the new Contractor to the daily PPA.
>> He has also transitioned the Contractor widgets to the new API, but Dan
>> doesn't want any widgets interfacing with Contractor in Granite, so the
>> merge request deprecates them instead of updating them.
>> All that's left is to document the API (unfortunately the old Contractor
>> API is undocumented too) and to transition applications to the new API. It's
>> easy and will instantly fix multiple bugs (e.g. Scratch printing problems
>> Cassidy complained about).
>> 2013/3/30 Sergey "Shnatsel" Davidoff <sergey@xxxxxxxxxxxxxxxx>
>>> Hey guys,
>>> I have some unpleasant things to bring up. Sorry for the long post, I
>>> hope it will not end up being another "TL;DR". (Come on, this is important!)
>>> As I've already reported, the current Contractor API is flawed. It relies
>>> on the client app calling Process.spawn_command_line_async on the string
>>> Contractor returns, which is bad for a long list of reasons. The most
>>> apparent one is being unable to handle filenames with spaces in them! This
>>> particular bug can be worked around in Contractor in an ugly way, but other
>>> issues remail and the API is not future-proof, so we'll have to break it and
>>> Granite API/ABI sooner or later (because Granite provides widgets and
>>> convenience functions for accessing Contractor API). Obviously it's better
>>> done sooner than later, while we don't have much code to transition and
>>> before the relevant Granite widgets get into a stable release.
>>> The more future-proof approach is to return a contract identifier to the
>>> client app and make the app call Contractor again to execute an action,
>>> passing it the identifier and the filename. This way Contractor can use
>>> proper process-launching functions or use completely different last-mile
>>> data transfer mechanisms, so we'll be able to add support for streaming data
>>> without writing it to disk or invoking D-bus methods, all without breaking
>>> the API in the future.
>>> I've investigated the problems of the current Contractor and wrote a
>>> better specification, detailing its expected behavior and the required API
>>> changes. I've discussed it with the original Python Contractor authors and
>>> got the green light from them. Michael Lazarski (lampe2) has taken a stab at
>>> cleaning up Ammonkey's code and implementing the spec, but he's currently
>>> preoccupied by contracted work (no pun intended). His Contractor branch can
>>> be found at lp:contractor.
>>> Additionally, I've looked into the state of Contractor support in Granite
>>> and elementary applications. In short, it's not glamorous.
>>> None of the apps use the Granite-provided ContractorMenu widget for the
>>> "Export" button; every single app reinvents the wheel and populates regular
>>> GTK menu with items acquired from Granite's Contractor wrapper. Maya (the
>>> least ugly implementation I've seen so far) even has a dedicated widget
>>> that's a clone of ContractorMenu!
>>> The other Contractor widget, ContractorView, is used only by Eidete where
>>> it doesn't seem to work; not sure if that's Contractor's fault or Eidete's.
>>> Finally, I don't understand why Granite has a wrapper for Contractor - it
>>> doesn't seem to reduce complexity or abstract anything. Using the D-bus API
>>> directly requires almost the same amount of code.
>>> So IMO the proper course of action is the following:
>>>  * Rework Contractor's D-bus API according to my specification
>>>  * Deprecate/abolish the Contractor wrapper in Granite
>>>  * Update Granite widgets and Pantheon Files to work with the new D-bus
>>> API
>>>  * Migrate other applications to using the Granite widgets (currently
>>> Maya, Scratch, Midori and elementary-flavored Simple Scan)
>>> However, I'm not sure this course of action is feasible for Luna.
>>> I'm absolutely not OK with releasing Granite with an API so flawed and
>>> which we're going to break in the future, so the alternative is to replace
>>> the current Contractor wrapper functions with stubs, mark them deprecated
>>> and replace Granite functionality in apps with something else.
>>> The options that spring to mind are:
>>>  * Replace Contractor actions with "Open With"
>>>  * Replace Contractor actions with a roughly similar but severely limited
>>> nautilus-sendto. Despite its name it's not actually related to Nautilus.
>>> This way we get sending files by bluetooth, email and IM; the catch is that
>>> Geary is not supported by nautilus-sendto, so we'll have to implement it (it
>>> should be done sooner or later for decent integration with Ubuntu).
>>>  * Remove the "Export" button from apps altogether
>>> Thoughts?
>>> --
>>> Sergey "Shnatsel" Davidoff
>>> OS architect @ elementary
>> --
>> Sergey "Shnatsel" Davidoff
>> OS architect @ elementary
> --
> Sergey "Shnatsel" Davidoff
> OS architect @ elementary

Sergey "Shnatsel" Davidoff
OS architect @ elementary

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