Re: [Evolution-hackers] If an account changes, who regenerates the services?

[Matthew Barnes <mbarnes redhat com>]

On Tue, 2010-10-19 at 14:10 -0500, Federico Mena Quintero wrote:
> I'm trying to unwind some code in Camel and in Evolution.
> 
> The problem I have is that if you change an email account's extra
> options (e.g. imapx's "apply filters to new messages"), then those
> changes don't take effect until you restart Evolution.
> 
> That option is a "filter" parameter in a CamelURL - the URL for the
> IMAPX service.
> 
> As far as I can tell, the only place where an IMAPX service gets this
> URL is at construction time.  However, a breakpoint at imapx_construct()
> only gets hit when I start up Evolution, not afterward (e.g. after
> changing the account's options in the account editor).
> 
> There is a lot of code around the account editor to apparently propagate
> changes.  But I'm rather lost in the structure.
> 
> em-account-editor changes the EAccount in emae_commit(), by calling
> e_acount_import().  Then it does e_account_list_change().  Both of those
> functions emit signals about something changing.
> 
> That's where I'm lost.
> 
> Does anyone know what links both parts of the code - the account editor
> and the actual construction of Camel services?

The 100,000 ft. answer is that trying to represent an account and its
various options as a URL string is a broken concept and another deep
design flaw in Camel.  Change any option that results in a different URL
string and Camel treats it as a completely new account, sets up all new
cache storage for it, and doesn't even clean up the old cache.  Camel
needs to have some kind of account object onto which meta-data can be
added and altered.

But to actually answer your questions, CamelStores are loaded from
EAccounts at startup in mail/e-mail-store.c:mail_store_load_accounts().
Once loaded, the CamelStore object is added to the EMFolderTreeStore,
which serves as the model for the folder tree view in the side bar.

EMFolderTreeStore responds to the "account-changed" signal by removing
the CamelStore object associated with the changed EAccount, and loading
a new one.  I'm not exactly sure how that's handled within Camel, but my
guess is this is the source of the problem.

That's the only place I'm aware of that anything meaningful happens.
The other "account-changed" handlers are for custom widgets that just
list the accounts, like EAccountComboBox which appears in the composer.

Hope this helps.