class and extending interface in objective c

Question

I know bit of ts and I am new to Objective C.

I have a meeting param which I want to extend in meeting obj (MeetingConfig.h) file

@interface MeetingParams : NSObject
  @property (nonatomic, assign) NSString* roomName;
  @property (nonatomic, assign) NSString* authToken;
  @property (nonatomic, assign)Boolean autoTune;
  @property (nonatomic, assign)NSString* apiBase;
  @property (nonatomic, assign)Boolean showSetupScreen;
@end

@interface MeetingConfig : NSObject
@property (nonatomic, assign) NSString* roomName;
@property (nonatomic, assign) NSString* authToken;
@property (nonatomic, assign)Boolean autoTune;
@property (nonatomic, assign)NSString* apiBase;
@property (nonatomic, assign)Boolean showSetupScreen;

- (void) setAuthToken:(NSString *)authToken;
- (void) setApiBase:(NSString *)apiBase;
- (void) setShowSetupScreen:(Boolean)showSetupScreen;
- (void) setAutoTuneEnabled:(Boolean)autoTune;
- (id) init;
@end

How can I do that? (right now I know there is redundant code)

Also, I know I am mixing language but can someone tell me what would be the equivalence of this code from Java in objective C?

 MeetingConfig config = new MeetingConfig();
        config.setRoomName("abc");

For now, I have made this as MeetingConfig.m file

#import "MeetingConfig.h"

@implementation MeetingConfig

- (id) init
{
  if (self = [super init]) {
    self.apiBase = @"https://api.xyz.in";
    self.showSetupScreen = false;
    self.autoTune = true;
  }
  return self;
}

- (void) setAuthToken:(NSString *)authToken
{
  self.authToken = authToken;
}
- (void) setApiBase:(NSString *)apiBase
{
  self.apiBase = apiBase;
}
- (void) setShowSetupScreen:(Boolean)showSetupScreen
{
  self.showSetupScreen = showSetupScreen;
}
- (void) setAutoTuneEnabled:(Boolean)autoTune
{
  self.autoTune = autoTune;
}

@end

Which I am hoping is equivalent to my this file

package com.dyteclientmobile;

public class MeetingConfig {
    public String roomName;
    public String authToken;
    public boolean autoTune;
    public String apiBase;
    public boolean showSetupScreen;

    public MeetingConfig() {
        this.apiBase = "https://api.xyz.in";
        this.showSetupScreen = false;
        this.autoTune = true;
    }

    public MeetingConfig setRoomName(String roomName) {
        this.roomName = roomName;
        return this;
    }

    public MeetingConfig setAuthToken(String authToken) {
        this.roomName = roomName;
        return this;
    }

    public MeetingConfig setApiBase(String apiBase) {
        this.apiBase = apiBase;
        return this;
    }

    public MeetingConfig setShowSetupScreen(boolean showSetupScreen) {
        this.showSetupScreen = showSetupScreen;
        return this;
    }

    public MeetingConfig setAutoTuneEnabled(boolean autoTune) {
        this.autoTune = autoTune;
        return this;
    }
}

MeetingConfig and MeetingParams seems the same, it look like one will do the job. and, the setter method will be created by default if no special usage.so I guess just keep MeetingConfig, and remove the setter method, it seems more clear. — childrenOurFuture, Jun 16 '21 at 06:46

score 1 · Accepted Answer · answered Jun 12 '21 at 07:11

Just for the MeetingConfig definition, you can do something like, in MeetingConfig.h:

#import <Foundation/Foundation.h>

@interface MeetingConfig : NSObject

@property(nonatomic, assign, readonly) NSString *roomName;
@property(nonatomic, assign, readonly) NSString *authToken;
@property(nonatomic, assign, readonly) BOOL autoTune;
@property(nonatomic, assign, readonly) NSString *apiBase;
@property(nonatomic, assign, readonly) BOOL showSetupScreen;

- (id)init;
- (MeetingConfig *)setAuthToken:(NSString *)authToken;
- (MeetingConfig *)setRoomName:(NSString *)roomName;
- (MeetingConfig *)setApiBase:(NSString *)apiBase;
- (MeetingConfig *)setShowSetupScreen:(BOOL)showSetupScreen;
- (MeetingConfig *)setAutoTuneEnabled:(BOOL)autoTune;

@end

and, in MeetingConfig.m:

#import "MeetingConfig.h"

@implementation MeetingConfig

- (id)init {
  if (self = [super init]) {
    _apiBase = @"https://api.xyz.in";
    _showSetupScreen = false;
    _autoTune = true;
  }
  return self;
}

- (MeetingConfig *)setAuthToken:(NSString *)authToken {
  _authToken = authToken;
  return self;
}

- (MeetingConfig *)setRoomName:(NSString *)roomName {
  _roomName = roomName;
  return self;
}

- (MeetingConfig *)setApiBase:(NSString *)apiBase {
  _apiBase = apiBase;
  return self;
}

- (MeetingConfig *)setShowSetupScreen:(BOOL)showSetupScreen {
  _showSetupScreen = showSetupScreen;
  return self;
}

- (MeetingConfig *)setAutoTuneEnabled:(BOOL)autoTune {
  _autoTune = autoTune;
  return self;
}

@end

Finally, an example of using this:

#import "MeetingConfig.h"

void printConfig(MeetingConfig *);

int main(int argc, char **argv) {
  MeetingConfig *config = [[MeetingConfig alloc] init];
  printConfig(config);
  [[[config setRoomName:@"abc"] setAuthToken:@"def"] setApiBase:@"http://localhost:8080"];
  printConfig(config);
}

void printConfig(MeetingConfig *config) {
  printf("roomName:         %s\n", [config.roomName UTF8String]);
  printf("authToken:        %s\n", [config.authToken UTF8String]);
  printf("autoTone:         %d\n", config.autoTune);
  printf("apiBase:          %s\n", [config.apiBase UTF8String]);
  printf("showSetupScreen:  %d\n", config.showSetupScreen);
}

The important differences between this and what you had put together:

Addition of the readonly attribute to each property, to ensure the corresponding set* methods weren't synthesised, as they would conflict with the fluent versions
Modification to init and setters to update the instance variables directly
Changing the signature and implementation of each setter method to return a pointer to self, making them fluent

You'll need to take a look a the documentation for @property, and other sources to get a sense of which attributes need to be set, I don't have enough experience to be absolutely sure on that front.

class and extending interface in objective c

1 Answers1