code generation objective-c

General
1

When creating the data tables it’s common to have a number of relationships between each table. When generating code this results in references between the generated classes. In languages like Objective-C where the interface is separate from the implementation you can’t have 2 files where each includes the other. i.e. User.h can’t include Business.h if Business.h also includes User.h

For the Objective-C case the .h files should use @class and the import should go in the .m file. Currently this modification needs to be made manually.

2

Additionally, for swift compatibility, relationship properties should be defined with additional type information, such as:

@property (strong, nonatomic) NSArray<User *> * users;

Though this does limit the application to more current version of the Xcode toolchain (though that shouldn’t be an issue in practice).

3

Hi Wain,

Could you provide your code generated project with your data model classes to support@backendless.com - we investigate these problems and will fix it in our next server-side release.

Thank you,
Slava

4

Hi Slava,

This isn’t a problem as such, it’s just some recommendations about how the Objective-C code generation can be improved. In order to get the code to compile initially I needed to make the @class changes and then to use with Swift effectively I made the arrays strongly typed.

For example, a code generated file started as:

#import <Foundation/Foundation.h>


#import "Place.h"


@interface Business : NSObject


@property (strong, nonatomic) Place * location;
@property (strong, nonatomic) NSArray * members;




@end

and I edited it to:









#import <Foundation/Foundation.h>




@class Place;


@class Membership;




@interface Business : NSObject


@property (strong, nonatomic) Place * location;

@property (strong, nonatomic) NSArray<Membership *> * members;




@end
5

I just created the Data/CRUD project with codegen.
My data model classes have 1:1 and 1:N relations:

class Address : NSObject {
 
 var street : NSString?
 var city: NSString?
 var state : NSString?
}

class Contact : NSObject {
 
 var objectId : String?
 var name : String?
 var age : Int = 0
 var phone : String?
 var title : String?
 var homeAddress : Address?
 var weight : Double = 0.0
}

class PhoneBook : NSObject {
 
 var objectId : String?
 var owner : Contact?
 var contacts : [Contact] = []
 var status : Int = 0
}

In code generated project these classes are:

  • Address.h:
#import <Foundation/Foundation.h>

@interface Address : NSObject
@property (nonatomic, strong) NSDate *created;
@property (nonatomic, strong) NSString *state;
@property (nonatomic, strong) NSString *city;
@property (nonatomic, strong) NSString *ownerId;
@property (nonatomic, strong) NSString *street;
@property (nonatomic, strong) NSDate *updated;
@property (nonatomic, strong) NSString *objectId;
@end
  • Contact.h
@class Address;

@interface Contact : NSObject
@property (nonatomic, strong) NSString *ownerId;
@property (nonatomic, strong) NSDate *created;
@property (nonatomic, strong) NSNumber *age;
@property (nonatomic, strong) NSString *name;
@property (nonatomic, strong) NSString *title;
@property (nonatomic, strong) NSDate *updated;
@property (nonatomic, strong) NSString *objectId;
@property (nonatomic, strong) NSString *phone;
@property (nonatomic, strong) Address *homeAddress;
@end
  • PhoneBook.h:
#import <Foundation/Foundation.h>

@class Contact;

@interface PhoneBook : NSObject
@property (nonatomic, strong) NSString *objectId;
@property (nonatomic, strong) NSDate *updated;
@property (nonatomic, strong) NSString *ownerId;
@property (nonatomic, strong) NSDate *created;
@property (nonatomic, strong) Contact *owner;
@property (nonatomic, strong) NSMutableArray *contacts;

-(void)addToContacts:(Contact *)contact;
-(void)removeFromContacts:(Contact *)contact;
-(NSMutableArray *)loadContacts;
-(void)freeContacts;
@end

I didn’t find any #include … directive in .h files, only @class …
Please, provide your classes, which demonstrated this issue, we can’t reproduce it.

6

I just regenerated the model files from code generation and I see the same result as you now with no imports. I previously generated them about 10 days ago.

Thanks

7

Ok, we are going to add the collection generics in a codegen section in our next release. Thank you for your recommendations.

8

To note on this, it seems that the code generation is different between the general code generation section and the code generation when selected from a custom business logic deployment. General code generation uses @class but the custom business logic code generation uses #import

9

Custom business logic code generator cannot produce objective-c, it creates only Java, PHP and JavaScript.

10

I mean from viewing the custom business logic deployed hosted service where you can download the service SDKs:

Download Service SDKs: https://develop.backendless.com/images/ANDROID-sk.png</img> Android/Java https://develop.backendless.com/images/IOS-sk.png</img> Obj-C/Swift https://develop.backendless.com/images/JS-sk.png</img> JavaScript https://develop.backendless.com/images/AS-sk.png</img> ActionScript https://develop.backendless.com/images/WP-sk.png</img> .NET

11

Thanks for clarifying. You’re talking about the generated SDKs for your API Engine service - the option available under the “Hosted Services” menu. I was referring to event handlers and timers.