Re: Plugins Utilizing Core Data NSManagedObjectContext

FROM : Marc Blatt
DATE : Thu Nov 29 22:32:37 2007

Thanks for the response and my apologies for the delayed 
acknowledgment. How much of a performance hit does this approach 
involve?  Is the size of the archived NSDictionary with undefined 
keys the reason for this or is it inherent in the architecture of the 
"special kind of managed object" that you provide in the primary app? 
Or is there another reason for this hit? Our app would not only 
require adding functionality and user data entry fields specific to 
the plugin's subject matter, but would also require subject matter 
data from the plugin to populate popup menus with data for quick 
entry (simple ex., popup menu populated with types of indie 
contractors--electrician, plumber, roofer, etc.). However, the data 
provided by the plugin for our app will require substantially more 
subject matter data and fields.

Thanks again,

Marc

On Nov 21, 2007, at 3:59 AM, Mike Abdullah wrote:

> Depending upon the level of performance from the store you require, 
> you might the consider the rough approach we took in Sandvox. There 
> are two parts:
>
> 1.
> So that plugin models don't have to be merged with the main 
> application model we provide a special kind of managed object that 
> can accept values for any key. Basically we implement -
> undefinedValueForKey: and -setValue:forUndefinedKey: such that the 
> values are actually kept in an archived NSDictionary. This allows 
> plugin writers to store whatever data they like without having to 
> worry about Core Data. They don't have to provide their own managed 
> object model.
>
> 2.
> Plugin writers then provide  what is known as a "plugin delegate." 
> This is a non-Core Data object that we automatically hook up to the 
> equivalent plugin object in the model. It receives various delegate 
> messages from the model so that the behaviour can be fully controlled.
>
>
> Mike.
>
> On 18 Nov 2007, at 06:54, Marc Blatt wrote:
>

>> Hello Everyone,
>>
>> I have an app that I want to extend its functionality with plugins 
>> that also provide additional data stored and accessed via Core 
>> Data. The thought is that the app has a standard (primary) 
>> persistent store containing app specific data, besides the user's 
>> data. Each plugin would provide additional functionality, 
>> including more sophisticated app specific data relating to the 
>> added functionality of the specific plugin. Without the specific 
>> plugin loaded, the additional app specific data does not exist. My 
>> thoughts are to create a moc for each plugin that contains the 
>> added specific data and merge it with the primary moc.
>>
>>