Objective-C How to add objects to NSMutableArray from other place? - ios

Question

Hello I'm junior in Objective-C and Swift programming.
I have NSMutableArray in ExampleMenuViewController.m or(and) SomeClass.m declared as vcTabs.
NSMutableArray *vcTabs;
When I have two declares 'vcTabs' Xcode returns duplicate symbol '_vcTabs' (...)
How to add objects to an existing NSMutableArray init in other class (ExampleMenuViewController.m)?
I need append new objects from another class (SomeClass.m) to vcTabs (NSMutableArray).
I wrote in SomeClass.m this code:
if ([Tools isNonullValueForKey:[dictionary valueForKey:#"additional_tabs"]]) {
additional_tabs = [dictionary valueForKey:#"additional_tabs"];
NSLog(#"additionalTabs count: %lu", [additional_tabs count]);
for (int i = 0; i < [additional_tabs count]; i++) {
if ([Tools isNonullValueForKey:[additional_tabs valueForKey:#"_id"]]) {
additional_tab_id = [[additional_tabs valueForKey:#"_id"] objectAtIndex:i];
}
if ([Tools isNonullValueForKey:[additional_tabs valueForKey:#"names"]]) {
NSDictionary *dic = [[additional_tabs valueForKey:#"names"] objectAtIndex:i];
_en_additional_tab_name = [dic valueForKey:#"en"];
_pl_additional_tab_name = [dic valueForKey:#"pl"];
}
if ([Tools isNonullValueForKey:[additional_tabs valueForKey:#"url"]]) {
additional_tab_url = [[additional_tabs valueForKey:#"url"] objectAtIndex:i];
//NSLog(#"additional_tab_url: %#", _additional_tab_url);
}
[vcTabs addObject:[[VCTab alloc] initWithIdAndTypeAndUrl:additional_tab_id :VCTabAdditional :additional_tab_url]];
NSLog(#"%# %d %# %# %# %#", #"pos", i, #"id: ", additional_tab_id, #"url: ", additional_tab_url);
}
}
ExampleMenuViewController method with initVCTabs
- (void)initVCTabs {
vcTabs = [[NSMutableArray alloc] init];
[vcTabs removeAllObjects];
if ([Tools getBooleanUserDefault:#"example_visible_tab_attendees" :YES]) {
[vcTabs addObject:[[VCTab alloc] initWithType:VCTabAttendees]];
}
(...)
if ([Tools getBooleanUserDefault:#"example_visible_tab_user_info" :YES]) {
[vcTabs addObject:[[VCTab alloc] initWithType:VCTabUserInfo]];
}
if ([Tools getStringUserDefault:#"example_additional_tab_id" :#""]) {
NSString *additionalTabId = [Tools getStringUserDefault:#"conference_additional_tab_id" :#""];
NSString *additionalTabUrl = [Tools getStringUserDefault:#"conference_additional_tab_url" :#""];
NSLog(#"additionalTabId %#", additionalTabId);
NSLog(#"additionalTabUrl %#", additionalTabUrl);
[vcTabs addObject:[[VCTab alloc] initWithIdAndTypeAndUrl:additionalTabId :VCTabAdditional :additionalTabUrl]];
}
}
PS. If I use from ExampleMenuViewController I have only one tab with last object properties... but additional_tabs array have 17 objects.
Do you have any ideas or advices?
All the best for you everyone!

Answer 1

When are you calling initVCTabs?
When / how is the code in SomeClass.m running?
For being a "junior in Objective-C and Swift programming" you seem to have a lot going on that you don't understand yet. Try creating a new project and learn how things work -- then implement that in your full project.
Here is a very, very simple example. With the information you provided in your question, this may or may not relate directly - but it should give you an idea of where to go:
SomeClass.h
// SomeClass.h
// Created by Don Mag on 8/30/20.
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
#interface SomeClass : NSObject
- (void)moreTabs:(NSMutableArray *)a;
#end
NS_ASSUME_NONNULL_END
SomeClass.m
// SomeClass.m
// Created by Don Mag on 8/30/20.
#import "SomeClass.h"
#interface SomeClass()
#end
#implementation SomeClass
- (void)moreTabs:(NSMutableArray *)a {
[a addObject:#"B"];
[a addObject:#"C"];
[a addObject:#"D"];
[a addObject:#"E"];
}
#end
ExampleMenuViewController.h
// ExampleMenuViewController.h
// Created by Don Mag on 8/30/20.
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
#interface ExampleMenuViewController : UIViewController
#end
NS_ASSUME_NONNULL_END
ExampleMenuViewController.m
// ExampleMenuViewController.m
// Created by Don Mag on 8/30/20.
#import "ExampleMenuViewController.h"
#import "SomeClass.h"
#interface ExampleMenuViewController ()
{
NSMutableArray *vcTabs;
}
#end
#implementation ExampleMenuViewController
- (void)viewDidLoad {
[super viewDidLoad];
// add a button to the view
//UIButton *b = [UIButton new];
UIButton *b = [UIButton buttonWithType:UIButtonTypeSystem];
[b setTitle:#"Tap Me" forState:UIControlStateNormal];
b.frame = CGRectMake(0, 0, 200, 50);
b.center = self.view.center;
[self.view addSubview:b];
[b addTarget:self action:#selector(btnTapped) forControlEvents:UIControlEventTouchUpInside];
[self initVCTabs];
[self logArray];
}
- (void)initVCTabs {
// instantiate NSMutableArray
vcTabs = [NSMutableArray new];
// add one object
[vcTabs addObject:#"A"];
}
- (void)btnTapped {
SomeClass *sc = [SomeClass new];
[sc moreTabs:vcTabs];
[self logArray];
}
- (void)logArray {
NSLog(#"vcTabs has %ld objects", [vcTabs count]);
for (NSString *s in vcTabs) {
NSLog(#"%#", s);
}
}
#end
When ExampleMenuViewController loads, it will add a button to the center of the view, then instantiate the vcTabs array and add one object - #"A".
We log the array to the debug console and see:
vcTabs has 1 objects
A
When you tap the button, an instance of SomeClass will be created, we call the moreTabs method in that class, passing a reference to vcTabs. That method will add 4 objects to the array - #"B" #"C" #"D" #"E".
We then log the array to the debug console and see:
vcTabs has 5 objects
A
B
C
D
E

Answer 2

#DonMag
It's working but I have one question to you. I added for loop to increment. When I add [additional_tabs count] is return nil. Why this method adds the same objects? My code in addMore function:
- (void)moreTabs:(NSMutableArray *)a {
for (int i = 1; i < additional_tab_count; i++) {
NSString *additionalTabId = [Tools getStringUserDefault:#"conference_additional_tab_id" :#""];
NSString *additionalTabUrl = [Tools getStringUserDefault:#"conference_additional_tab_url" :#""];
[a addObject:[[VCTab alloc] initWithIdAndTypeAndUrl:additionalTabId :VCTabAdditional :additionalTabUrl]];
}
}
Do you know how to get THIS "dictionary" or "additional_tabs". I tried but always return nil (looks like a new other instance and is not this dictionary or additional_tabs from initFromJSON). I only managed to make variable additional_tab_count and it's return 17 (correct count), but I'd rather have access to array from additional_tabs declared in if statements.