gtg-user team mailing list archive

[Luca Invernizzi <invernizzi.l@xxxxxxxxx>]

On Tue, Nov 15, 2011 at 3:49 PM, Germán Gutiérrez <germang@xxxxxxxxx> wrote:
> Thanks! It served me as a model to get started with it, I have a very
> early draft, add only, jira backend, I'm slowly progressing with this
> since I'm doing it on my spare time, which is too little  :)
>
> I started with the twitter backend as a model that seems very
> simple... in fact it is batantly based on it
>
> BTW, Can you explain what SyncMeme is about?

Hello German,
the SyncMeme holds the relationship between the local GTG task, and
the remote Jira task.
In particular:
 - it knows which GTG task is the local copy of which Jira task
 - it knows what was the state of both tasks last time a sync happened.
When a sync happens, the SyncEngine looks at the current status of
local and remote tasks, and comparing that to the data in the
SyncMeme, it decides which task should be updated/deleted/added.
>
>
> Regards,
>
> Germán.
>
> On Thu, Nov 10, 2011 at 7:40 PM, Izidor Matušov
> <izidor.matusov@xxxxxxxxx> wrote:
>> Hi Germán,
>>
>> Am 10.11.2011 01:44, schrieb Germán Gutiérrez:
>>>
>>> Izidor, looks like you are the master in this, any helloworld.py
>>> equivalent in backend world?
>>
>> Unfortunately, there is no well-written documentation or any helloworld.
>> (The feature was still not released).
>>
>> I recommend you to get
>>
>> bzr branch lp:~gtg-contributors/gtg/google_tasks
>>
>> and look at backends for launchpad and google tasks. They are in general
>> very similar although they do different things. (Google Tasks synchronize
>> your tasks, launchpad only imports tasks)
>>
>> Luca: I was thinking about lowering the barrier for writing a new backend.
>> There is a lot of redundant code for every backend (they are pretty much the
>> same). What about making more high level interface so "user programmer" just
>> provides the minimum of information (authenticate yourself, this is list of
>> remote tasks, add to GTG tasks which you do not have, give me tasks, that
>> has changed or were deleted so I can update them on server) I think it is
>> sufficient to specify only those 3 things and details can be solved by
>> internal, high-level interface. The goal might be to write a brand new,
>> simple backend under 99 lines of code. What do you say? Do you want to work
>> on it at the hackathon on 26th?
>>
>> A try to make a simple tutorial:
>>
>> 1, create file GTG/backends/backend_yourname.py
>> 2, (optional) put icon of for your backend as
>> data/icons/hicolor/scalable/apps/backend_yourname.png
>> 3, open GTG/backends/backend_yourname.py and some other backend for
>> inspiration
>> 4,  You have to include a lot of GTG import statements to get all things you
>> need.
>> 5, Put external library you need. (There might be already python bindings
>> for your service or protocol)
>> 6, Create a new class called Backend, extend PeriodicImportBackend
>> 7, Put description for your backend, e.g.:
>>    _general_description = {
>>        GenericBackend.BACKEND_NAME: "backend_gtask",
>>        GenericBackend.BACKEND_HUMAN_NAME: _("Google Tasks"),
>>        GenericBackend.BACKEND_AUTHORS: ["Madhumitha Viswanathan", "Izidor
>> Matušov"],
>>        GenericBackend.BACKEND_TYPE: GenericBackend.TYPE_READWRITE,
>>        GenericBackend.BACKEND_DESCRIPTION:
>>            _("This backend synchronizes your tasks with the web service "
>>              "Google Tasks\n\n"
>>              "Note: This product uses the Google Tasks API but is not "
>>              "endorsed or certified by Google Tasks"),\
>>        }
>>
>> 8, Put parameters for your backend (e.g. username, other parameters):
>>    _static_parameters = {
>>        "username": { \
>>            GenericBackend.PARAM_TYPE: GenericBackend.TYPE_STRING, \
>>            GenericBackend.PARAM_DEFAULT_VALUE: "insert your username here"},
>> \
>>        "period": { \
>>            GenericBackend.PARAM_TYPE: GenericBackend.TYPE_INT, \
>>            GenericBackend.PARAM_DEFAULT_VALUE: 2, },
>>        "import-bug-tags": { \
>>            GenericBackend.PARAM_TYPE: GenericBackend.TYPE_BOOL, \
>>            GenericBackend.PARAM_DEFAULT_VALUE: False}, \
>>        "tag-with-project-name": { \
>>            GenericBackend.PARAM_TYPE: GenericBackend.TYPE_BOOL, \
>>            GenericBackend.PARAM_DEFAULT_VALUE: True}, \
>>        }
>>
>> 9, in the constructor, call parent's constructor, initilialize pickle file
>> (pickle is used for serialization of data) for sync_engine which keeps
>> relation between local and remote tasks. Initialize internal variables:
>>
>>    def __init__(self, parameters):
>>        '''
>>        See GenericBackend for an explanation of this function.
>>        Re-loads the saved state of the synchronization
>>        '''
>>        super(Backend, self).__init__(parameters)
>>        #loading the saved state of the synchronization, if any
>>        self.data_path = os.path.join('backends/launchpad/', \
>>                                      "sync_engine-" + self.get_id())
>>        self.sync_engine = self._load_pickled_file(self.data_path, \
>>                                                   SyncEngine())
>>
>> 10, When an instance of your backend is created and enabled (the user has
>> added new backend, set parameters like username and clicked on "Enable
>> syncing"), initialize() method is called. You can use it to start your
>> authentication.
>>
>> There is code for storing password in GNOME keyring (if it is not
>> accessible, GTG will forget password after restart) or use authentication
>> procedure of your webservice. (Look at other backends for inspiration)
>>
>>
>> (hardcore begins)
>> 11, do_periodic_import(): once in while is this function called. Firstly,
>> you fetch all tasks on the remote side. Then you put that task into
>> sync_engine. It automagicaly tells youwhether you should add this task to
>> local GTG, remove it or update it.
>>
>> Later you ask for a difference between list of your local tasks and list of
>> your remote tasks, and those tasks should be deleted..
>>
>> 12, Test it and polish it :-)
>>
>> Around this state, you should have about 500 lines of code and a prototype
>> of your backend.
>>
>> If you want, you can join us on Saturday, November 26 at online hackathon
>> and your questions will be answered in the real time :-)
>>
>> Please, write down questions you have. We can from our communication put
>> together very first version of how to write your first backend in 13 steps
>> :-)
>>
>> Izidor
>>
>
>
>
> --
> Saludos,
>                          Germán
>
> Delivering common sense since 1969 <Epoch Fail!>.
>
> The Nature is not amiable; It treats impartially to all the things.
> The wise person is not amiable; He treats all people impartially.
>