Using Xcode 6.2 and CoreData. I needed to rename a couple of entity names and recreate the NSManaged objects and noticed that the New Managed objects did not get named the same as the new entity names - the old name was used.
Here's some output from diff on the data model contents file:
- <entity name="SavedSignSets" representedClassName="SavedSignSets" syncable="YES">
+ <entity name="SavedSignSet" representedClassName="SavedSignSets" syncable="YES">
This a bug or am I doing something wrong?
UPDATE:
Exact problem is this:
I had an existing entity and corresponding managed object generated by Xcode 6.2. Entity and managed object had the same name.
I changed the Entity name.
I trashed the corresponding managed object files.
Using Xcode 6.2 I generate Managed Object for the entity - assuming the new name will be used
Xcode names the managed object using the old entity name.
select the entity and check the entity inspector in the utilities view's data model inspector (the left left menu), each entity has a name field and a class field. When you change the name in the GUI you only change the class name. To correct the error you to change the name as well.
The core data framework is a little finnicky in XCode. It has seemed to get confused in overwriting existing auto-generated files. I can't guarantee this is a fix, but you can try manually trashing your old Managed Object class file(s) from the XCode Navigation window (make sure you delete, and not just remove reference), and then creating the NSManagedObject subclass again under the guise of it being a new file.
In doing this, also manually check that any Relationship references in other files get updated with the new class name as well (sometimes they will load as the generic NSManagedObject class on one side of the relationship). It was taught to me as standard practice to trash the whole set of generated entity files and recreate them as a group.
(Also, I'm running XCode 6.1.1 so I'm not on your exact version)
Related
I'm trying to rename a core data entity (not an attribute) using Swift, iOS 13.0+. I currently have a Core Data Entity named Image, but since SwiftUI has a reserved view under that name, I'm trying to rename the entity to FileImage.
I have followed this post, but the data under that entity no longer remains on the device/mapped to the new entity. Any advice on how to rename a Core Data Entity without losing the data in that entity?
To rename CoreData entity:
Firstly set hash modifier and Renaming ID for your entity. Renaming ID should match the previous name of entity.
Select your .xcdatamodel in file navigator
Select "Add model version"
Expand .xcdatamodel in file navigator:
In file properties select a new version of .xcdatamodel:
Then rename entity name and entity class name:
After this you should rename your entity in all project.
Posting here for anyone else who needs to rename CoreData Entities (in order to avoid conflicts with SwiftUI reserved names).
Change the name of the class name for the entity (under Class in the Data Model Inspector), but do not change the name of the Entity.
You'll now have to change the name of the entity used throughout the code to the new updated class name. (FileImage -> Image), but the CoreData will no longer be in conflict with the SwiftUI reserved keyword, while maintaining all your data.
Using Version 8.1 of Xcode.
Create an entity named "MapRegionObject" in .xcdatamodeld file.
Using auto code generator, click Editor on the navigation bar -> create NSManagedOject Subclass...
Got two files : MapRegionObject+CoreDataClass.swift and MapRegionObject+CoreDataProperties
Errors in two files showing in the screenshot:
MapRegionObject+CoreDataClass.swift
MapRegionObject+CoreDataProperties
Please help me fix this bugs, thank you so much!
In Xcode 8.1, before using the auto code generator, you must select the entity in your data model:
Then go to the Data Model Inspector tab:
Under "Codegen" select "Manual/Node"
After that you could create a NSManagedObject subclass without errors.
Alternatively, if you have already used 'Class Definition', you can go into your existing .xcdatamodeld file and set all current entities to 'Manual/None' under Codegen. Make sure to save your project (File -> Save), delete your existing Derived Data, clean the project, and then build. Resolved it for me without having to re-make my whole model.
I found this whole thing to be very confusing. You really do need to understand what's new in CoreData. Basically, the default is to automatically generate the class and the extensions for you in a place called "DerivedData" that's buried in ~/Library/Developer/Xcode/DerivedData where these classes and their extensions live, outside of your code source. Personally, not being able to open and look at them is weird to me, but something to get used it.
Basically, if you have an entity called "AppSettings" in your CoreData model, you can just use it without needing to generate the code yourself. If you want the code in your project, then set the Codegen property on the entity to Manual/None. Then do what you did before: Editor->Create NSManagedObject classes, etc. The files will wind up in your project.
The good news is that if you want to make custom extensions, just do that in your project. Xcode will blend the generated files, from their other place outside your project directory, with the files in your project directory.
1) clean the project (cmd + shift + K)
2) In the "data model inspector" for every created Entity set attributes for Class just as in the screenshot below
3) Generate code again (Editor -> create NSManagedObject Subclasses)
After that everything should work fine.
The problem is that you don't need to generate NSManagedObjectModel subclasses manually anymore.
ref: https://forums.developer.apple.com/thread/48988
Xcode automatically generates classes or class extensions for the
entities and properties in a Core Data data model. Automatic code
generation is enabled and disabled on an entity by entity basis, and
is enabled for all entities in new models using the Xcode 8 file
format. This feature is available for any data model that has been
upgraded to the Xcode 8 format. You specify whether Xcode generates
Swift or Objective-C code for a data model using the data model’s file
inspector. When automatic code generation is enabled for an entity,
Xcode creates either a class or class extension for the entity as
specified in the entity's inspector: the specified class name is used
and the sources are placed in the project’s Derived Data. For both
Swift and Objective-C, these classes are directly usable from the
project’s code. For Objective-C, an additional header file is created
for all generated entities in your model: The file name conforms to
the naming convention 'DataModelName+CoreDataModel.h'.
Close the project and follow the following instructions:
Reveal in finder your database .xcdatamodeld file.
on .xcdatamodeld file right click -> Show Package Contents, if(.xcdatamodel) is find again in the package again right click and 'Show Package Contents'. you should get 'contents' file.
Open 'contents' in text edit.
Command-F (codeGenerationType="class") and replace all matchings string with blank string.
Save and open Xcode project again.Everything should work well.
In Xcode 8.2.1 , Menu-Product-Clean，And every is ok, it's so verid.
Don't fight the with Xcode on this unless you really need to alter your generated properties, doing so will just leave you frustrated.
Think of the auto-generated class as any other class in your application. If you need to add functionality to your managed object class, simply change your class definition into an extension and extend your object.
change your class:
class MyManagedObject : NSManagedObject { /* implementation*/ }
to an extension:
extension MyManagedObject { /* implementation */ }
This isn't an answer. It's just explanation of what's going on with the selections
Make sure you see this moment for the Core Data Stanford course
Below is a transcript I wrote myself (It's not 100% accurate):
The default is class definition, if you choose this one. It will
generate that subclass and it will just work. You'll be able to access
your tweets as a class called Tweet. This sounds good. Btw if you do
this it will NOT show up in your file navigator.
The one we choose the most often is the category/extension what this
will do it will only generate an extension of the Tweet class. You
have to actually write the tweet class itself. The extension will take
care of making all the vars. Even when I switch to category/extension
again I don't get that extension showing up in the navigator. It's
kind of hidden from you.
And why do we like this one? Because a lot of times we want to add our
own code. Like in a Tweet, imagine you want to add a static method
that took data from Twitter and turned it into a tweet in the
database. Where would we put code? Well a great place to put that code
would be in the Tweet class...if there was such a thing...and the
extension is going to handle all the var business for you.
If you did choose manual/none for codegen. meaning don't do any
codegen, then you would be doing value/setValue(forKey:)...good luck
with that You're code is going to be a mess. [ie there is no
.propertyName = value ...you'd had to do setValue(value, forKey:
propertyName)].
Long story short, I'm not sure why but for some reason if you don't select the create NSManagedObject subclass then it seems to still work, but without showing what's happening under the hood. Very counter intuitive!
Then also watch this live demo of the Core Data Stanford course:
Now we know we want to access all this stuff not using
value/set(value:forKey:)...we want to have to subclasses of
Users/Tweets. And we want to have vars [ dot notation] for all these
relationships so we need that code to be generate. The way we do that
we just select the entity... and we go down here to CodeGen. This says
by default class definition. That means it's done it. It has generate
a class called Tweet. and It's going to work with var and all
relationships. That's not actually what we want. We want to select
this one [Category/Extension]. Where only create an extension to Tweet
and add the var stuff. That's because we want to write the class
Tweet and put our own code in there. It's very common to write our
own class. But you still want the var magic.
I am working with CoreData, on an entity called "RoleName".
The problem is: I click on "Create NSManagedObject subclass" from within my model, and so it automatically creates the classes for my entity.
However, on the declaration of the class, I get this error:
Invalid redeclaration of "RoleName"
even though I don't have any other class with the same name.
This is because Xcode handles all that by itself. I felt it like a bit of trouble as the auto generated classes don't have all my properties.
So follow these steps to get this as it used to be:
Delete what ever classes you already made for core data.
Set class.Module as Current Product module
Set Class.codegen as Manual/None
Now select your entity and create NSmanagedobject subclass
You are all set
From Apple : Whats new in Core Data
Xcode automatic subclass generation
Xcode now supports automatic generation of NSManagedObject subclasses in the modeling tool. In the entity inspector:
Manual/None is the default, and previous behavior; in this case you should implement your own subclass or use NSManagedObject.
Category/Extension generates a class extension in a file named like ClassName+CoreDataGeneratedProperties. You need to
declare/implement the main class (if in Obj-C, via a header the
extension can import named ClassName.h).
Class Definition generates subclass files named like ClassName+CoreDataClass as well as the files generated for
Category/Extension.
The generated files are placed in DerivedData and rebuilt on the first build after the model is saved. They are also indexed by Xcode,
so command-clicking on references and fast-opening by filename works.
You don't need to manually create subclasses for NSManagedObjects.
I would suggest that you delete the files that you created with NSManagedObjects (Move them to Trash) and go to every entity in the DataModel Inspector under Codegen select : Manual / None and create than the Subclasses.
Using Version 8.1 of Xcode.
Create an entity named "MapRegionObject" in .xcdatamodeld file.
Using auto code generator, click Editor on the navigation bar -> create NSManagedOject Subclass...
Got two files : MapRegionObject+CoreDataClass.swift and MapRegionObject+CoreDataProperties
Errors in two files showing in the screenshot:
MapRegionObject+CoreDataClass.swift
MapRegionObject+CoreDataProperties
Please help me fix this bugs, thank you so much!
In Xcode 8.1, before using the auto code generator, you must select the entity in your data model:
Then go to the Data Model Inspector tab:
Under "Codegen" select "Manual/Node"
After that you could create a NSManagedObject subclass without errors.
Alternatively, if you have already used 'Class Definition', you can go into your existing .xcdatamodeld file and set all current entities to 'Manual/None' under Codegen. Make sure to save your project (File -> Save), delete your existing Derived Data, clean the project, and then build. Resolved it for me without having to re-make my whole model.
I found this whole thing to be very confusing. You really do need to understand what's new in CoreData. Basically, the default is to automatically generate the class and the extensions for you in a place called "DerivedData" that's buried in ~/Library/Developer/Xcode/DerivedData where these classes and their extensions live, outside of your code source. Personally, not being able to open and look at them is weird to me, but something to get used it.
Basically, if you have an entity called "AppSettings" in your CoreData model, you can just use it without needing to generate the code yourself. If you want the code in your project, then set the Codegen property on the entity to Manual/None. Then do what you did before: Editor->Create NSManagedObject classes, etc. The files will wind up in your project.
The good news is that if you want to make custom extensions, just do that in your project. Xcode will blend the generated files, from their other place outside your project directory, with the files in your project directory.
1) clean the project (cmd + shift + K)
2) In the "data model inspector" for every created Entity set attributes for Class just as in the screenshot below
3) Generate code again (Editor -> create NSManagedObject Subclasses)
After that everything should work fine.
The problem is that you don't need to generate NSManagedObjectModel subclasses manually anymore.
ref: https://forums.developer.apple.com/thread/48988
Xcode automatically generates classes or class extensions for the
entities and properties in a Core Data data model. Automatic code
generation is enabled and disabled on an entity by entity basis, and
is enabled for all entities in new models using the Xcode 8 file
format. This feature is available for any data model that has been
upgraded to the Xcode 8 format. You specify whether Xcode generates
Swift or Objective-C code for a data model using the data model’s file
inspector. When automatic code generation is enabled for an entity,
Xcode creates either a class or class extension for the entity as
specified in the entity's inspector: the specified class name is used
and the sources are placed in the project’s Derived Data. For both
Swift and Objective-C, these classes are directly usable from the
project’s code. For Objective-C, an additional header file is created
for all generated entities in your model: The file name conforms to
the naming convention 'DataModelName+CoreDataModel.h'.
Close the project and follow the following instructions:
Reveal in finder your database .xcdatamodeld file.
on .xcdatamodeld file right click -> Show Package Contents, if(.xcdatamodel) is find again in the package again right click and 'Show Package Contents'. you should get 'contents' file.
Open 'contents' in text edit.
Command-F (codeGenerationType="class") and replace all matchings string with blank string.
Save and open Xcode project again.Everything should work well.
In Xcode 8.2.1 , Menu-Product-Clean，And every is ok, it's so verid.
Don't fight the with Xcode on this unless you really need to alter your generated properties, doing so will just leave you frustrated.
Think of the auto-generated class as any other class in your application. If you need to add functionality to your managed object class, simply change your class definition into an extension and extend your object.
change your class:
class MyManagedObject : NSManagedObject { /* implementation*/ }
to an extension:
extension MyManagedObject { /* implementation */ }
This isn't an answer. It's just explanation of what's going on with the selections
Make sure you see this moment for the Core Data Stanford course
Below is a transcript I wrote myself (It's not 100% accurate):
The default is class definition, if you choose this one. It will
generate that subclass and it will just work. You'll be able to access
your tweets as a class called Tweet. This sounds good. Btw if you do
this it will NOT show up in your file navigator.
The one we choose the most often is the category/extension what this
will do it will only generate an extension of the Tweet class. You
have to actually write the tweet class itself. The extension will take
care of making all the vars. Even when I switch to category/extension
again I don't get that extension showing up in the navigator. It's
kind of hidden from you.
And why do we like this one? Because a lot of times we want to add our
own code. Like in a Tweet, imagine you want to add a static method
that took data from Twitter and turned it into a tweet in the
database. Where would we put code? Well a great place to put that code
would be in the Tweet class...if there was such a thing...and the
extension is going to handle all the var business for you.
If you did choose manual/none for codegen. meaning don't do any
codegen, then you would be doing value/setValue(forKey:)...good luck
with that You're code is going to be a mess. [ie there is no
.propertyName = value ...you'd had to do setValue(value, forKey:
propertyName)].
Long story short, I'm not sure why but for some reason if you don't select the create NSManagedObject subclass then it seems to still work, but without showing what's happening under the hood. Very counter intuitive!
Then also watch this live demo of the Core Data Stanford course:
Now we know we want to access all this stuff not using
value/set(value:forKey:)...we want to have to subclasses of
Users/Tweets. And we want to have vars [ dot notation] for all these
relationships so we need that code to be generate. The way we do that
we just select the entity... and we go down here to CodeGen. This says
by default class definition. That means it's done it. It has generate
a class called Tweet. and It's going to work with var and all
relationships. That's not actually what we want. We want to select
this one [Category/Extension]. Where only create an extension to Tweet
and add the var stuff. That's because we want to write the class
Tweet and put our own code in there. It's very common to write our
own class. But you still want the var magic.
I am having an issue using Core Data modeler. I had an issue where I needed to change the names of entities in the modeler. When I did so, I deleted the associated managed object subclasses, did a clean, then went back the modeler, highlighted the entities with the new names, then generated subclasses using
Editor > Create NSManagedObject Subclass
When I did so, the newly generated subclasses still have the original names. Am I missing something?
In the model editor, you set the class name separately from the entity name. They don't have to be the same. If you only change the entity name name, what you're seeing is normal.
Select the ENTITY you want to change
Select Data Model from right hand top corner as shown below, and change as u want. Entity name and Class no need to be the same.
Finally Clean and Build the project.