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

[Jeffrey Stedfast <fejj novell com>]

On 10/19/2010 03:52 PM, Matthew Barnes wrote:
> 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.

This isn't actually true... or at least it wasn't at one point. There
used to be (still is?) a CamelService comparer function that decides if
2 CamelURLs are for the same service. Each provider can override this
method. All that needs be done is ignore parts of the url that are
insignificant (like the query, for example).

The one area where this fell flat was if things like the port changed.

One solution to Federico's original query is that you could use the
camel_object_setv() API to set new parameters on an existing
CamelService (sorta like GObject's getv/setv).

I think that currently, a number of options are part of the URL and so
changing the URL might make the CamelService want to
disconnect/reconnect (assuming it works at all, this part of Camel was
never finished).

You could modify the service setv() code to be able to "diff" the URLs
and see what portions changed to decide whether or not the service
needed to reconnect or not and update state.

>   Camel
> needs to have some kind of account object onto which meta-data can be
> added and altered.
>   

Sure, but you still have the same problems you have now, just in a
different object :-)

Jeff