Core Data: Get Managed Object by unique part of the objectID

etresoft wrote:

DavidMan wrote:
*but I can not figure out how to get these objects using CoreData. I guess I should create the NSPredicate for the fetch request; but I don't know how to write the predicate which will give me the exact object based on the unique part of the objectID*

I think you are supposed to consider the entire ID to be unique. You can retrieve the associated object using "objectWithID:" from NSManagedObjectContext.

The problem is that I am parsing the text from another application and I have only the "unique part" at hand and not the whole objectID. So, I need to cope with that.

What I see is that the IDs of every entity start with the same text, e.g. here are the IDs of two different entities:
<x-coredata://A3EDF6C1-229D-4658-A04E-598ADF1C749A/Person/p317>
<x-coredata://A3EDF6C1-229D-4658-A04E-598ADF1C749A/Department/p5>

As you see, the difference is only in the end, after the entity names "Paper" and "Department". But this is my case and I am not completely sure that this will hold true for EVERY future installation on any system for every entity.

*Question: will the part like <x-coredata://A3EDF6C1-229D-4658-A04E-598ADF1C749A be constant for the particular installation, for every entity/object?*

If YES, then I will:
- after getting any/first object, extract the non-unique part, i.e. <x-coredata...749A which is the same for every object in this particular installation on this particular computer
- get the unique part, i.e. /Person/p317, /Person/p23, /Department/p5 etc.
- synthesize the "real ID" by appending these two strings
- ask managedObjectContext to return the object with this ID
- continue with the acquired object

How does it sound? Will this work on other computers?
P.S. FYI: the coredata of this program has only one store i.e. all the data are stored in single sqlite file.

etresoft wrote:

DavidMan wrote:

What are you actually trying to accomplish here? The big picture? It sure doesn't sound right.

*"The big picture":*
- There is a core data application (not mine, let's call it "foreign") with object in interest
- Foreign app has a tableview
- After drag and drop from the tableview to some text editor (e.g. TextEdit or Ms-Word), it pastes the "tag-like text"
- This tag, along with other info, contains the "unique reference number" to the object in its database. This reference number (the actual primary key in the sqlite3 file) is actually the last part of objectID I was talking about above.

*I need to:*
- catch these "tags" in the text file
- exchange them with additional info from the database of that foreign app.

*What I have managed already:*
- My app can find the tags in text
- Extract the reference numbers.

*Now I want to* use these reference numbers to go back to the database and grab the rest of the info to add it to the text document.

Because the foreign app is proprietary, I must use whatever info it provides (the tag), connect directly to its database and get the rest of the info by myself using the tag.
I admit that the picture is not perfect, but that foreign app does not have SDK/API, so I don't see any other solution.