System hooks to insert raw sql.
References on django-developers google group:
* https://groups.google.com/forum/?fromgroups#!topic/django-developers/xN0aMzrmA1Y
* https://groups.google.com/forum/?fromgroups#!topic/django-developers/KhsGj1b6rnU- All methods / hook-handlers should return a list of sql or raise NotImplementedError.
- I did not want to base all work in django signals, so I tried the sql generation for these hooks is quite simple and can be used both as sqlall syncdb. Additionally, the signals were implemented, will not be recommended, but will be available. All that is done in the signals will not be available at the output of sqlall.
- It is proposed to use the existing signal "post_syncdb" to model, app, and project. In my opinion is the signal used for more things you should. I will respect the decision, but I think it should have different signals for each case.
Add new parameter "type" to post_syncdb signal and add pre_syncdb signal without created_models parameter. type parameter identifies the context. Contexts: migrate, sync, flush.
Signals: TODO
The addition of two new settings to explicitly specify two handlers: pre and post syncdb at the project level. If these handlers are run with "connection" as a parameter.
pre_sync runs before anything, and post_sync runs at the end of everything.
Settings:
- settings.PROJECT_PRE_SYNCDB_HOOK
- settings.PROJECT_POST_SYNCDB_HOOK
By default, you will find two functions: "post_sync" and "pre_sync" in the models of the app. If they exist, are executed with "connection" as a parameter. The sql obtained from "pre_sync" runs just before starting to create tables, and sql obtained from "post_sync" runs after creating all the tables.
Signals
post_syncdb signal is sended on all models are created. pre_syncdb signal is sended for all apps before tables creation.
This is managed by two methods at model level, "get_post_sync_sql" and "get_pre_sync_sql". They should be decorated as "classmethod".
"get_post_sync_sql" are executed after all tables are created and are custom sql fixtures are loaded.
"get_pre_sync_sql" at the moment are not implemented. Not very clear to me when to run:
- For each model just before creating the tables?
- Before creating any table, run all sql pre_sync?
- project level signal on pre and post syncdb.
- post_flush hook for model.
- pre_sync hook for model.