Passing data to textView from another class - objective-c

Question

I know this is just a fundamental question but still somewhere I am missing something, I am playing with passing data to a textView from another class. For this I have created two classes one with xib file (ViewController) and another without(secondVC).
What I am trying to do is that I have a textview in ViewController class and wanted to pass the data to this textView from secondVC. This is how I am doing.
//ViewController.h
#import <UIKit/UIKit.h>
#import "secondVC.h"
#interface ViewController : UIViewController{
IBOutlet UITextView *textView;
}
#property (nonatomic, retain) UITextView *textView;
- (IBAction)go:(id)sender;
#end
//ViewController.m
- (IBAction)go:(id)sender{
secondVC *sec = [[secondVC alloc] init];
[sec print];
}
//secondVC.h
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface secondVC : UIViewController
- (void)print;
#end
//secondVC.m
- (void)print{
NSString *printThis = #"This works";
ViewController *vc = [[ViewController alloc] init];
[vc.textView setText:printThis];
//vc.textView.text = printThis //Tried both
}
Any suggestions would be appreciated.
Thanks

Answer 1

you can do like this :
//ViewController.h
#import <UIKit/UIKit.h>
#import "secondVC.h"
#interface ViewController : UIViewController{
IBOutlet UITextView *textView;
}
#property (nonatomic, retain) UITextView *textView;
- (IBAction)go:(id)sender;
#end
//ViewController.m
- (IBAction)go:(id)sender{
secondVC *sec = [[secondVC alloc] init];
sec.viewController = self;
[sec print];
}
//secondVC.h
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface secondVC : UIViewController {
ViewController *viewController;
}
#property(nonatomic, retain)ViewController *viewController;
- (void)print;
#end
//secondVC.m
#synthesize viewController;
- (void)print{
NSString *printThis = #"This works";
self.viewController.textView.text = printThis ;
}

Answer 2

Try with protocol... if you want to send string from textView(child) to other ViewController(parent)

Answer 3

You need a delegate method that is fired from the SecondVC and handled in the first one (ViewController).

Answer 4

There are a few issues here:
You've got a ViewController creating a new secondVC and sending it a print message. That's okay, but the implementation of -print creates a different instance of ViewController and tries to set the text of it's textView property. That's clearly not what you want -- you should instead be sending the text back to the original instance of ViewController.
That second instance of ViewController very likely has its textView property set to nil since textView is an outlet, but you haven't loaded its view from the .xib.
It's really not nice for one view controller to mess with the views of another view controller. The secondVC should be giving the text to the original ViewController object, not trying to set the text of one of its views.
To facilitate communication from secondVC to ViewController, give secondVC a property to keep track of the original ViewController. The usual thing to do here is to define a delegate protocol for secondVC and implement that protocol in ViewController. When ViewController creates secondVC, it sets the delegate of secondVC to itself. That gives secondVC a pointer to its delegate (it shouldn't care whether its a ViewController or some other kind of object, as long as the delegate implements the right methods).

Answer 5

.h file:
#import <UIKit/UIKit.h>
#protocol StringDelegate <NSObject>
-(void)getArrayOfStrings:(NSMutableArray*)strArray;
#end
#interface WWSettings : UIViewController{
}
#property(nonatomic,assign)id<StringDelegate>delegate;
#end
.m file:
#import "WWSettings.h"
#implementation WWSettings
#synthesize delegate;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
-(void)blablablaFunction{
[delegate getArrayOfStrings:yourArray];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}
#end
if you dont understand how it works .. ask ! i'll make my best to help you )
your secondVC
#import <UIKit/UIKit.h>
#import "WWSettings.h"
#interface secondVC : UIViewController<StringDelegate>{
WWSettings *obj;
}
#end
and .m file :
#import "secondVC.h"
#implementation secondVC
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
-(void)getArrayOfStrings:(NSMutableArray *)strArray{
// here you get your array !!! it's a delegate function made by you in child viewController;
}
- (void)viewDidLoad
{
obj = [[WWSettings alloc]init];
[obj setDelegate:self];
[super viewDidLoad];
// Do any additional setup after loading the view.
}

Answer 6

first VC .h file :
#import <UIKit/UIKit.h>
#protocol textViewChildDelegate <NSObject>
-(void)getStrings:(NSString*)string;
#end
#interface textViewChild : UIViewController<UITextViewDelegate>{
UITextView *textView;
}
#property(nonatomic,assign)id<textViewChildDelegate>delegate;
#end
.m file:
#import "textViewChild.h"
#implementation textViewChild
#synthesize delegate;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
-(void)myWorkingMethod{
// get string from textView
[delegate getStrings:textView.text];
}
- (void)viewDidLoad
{
textView = [[UITextView alloc]initWithFrame:CGRectMake(0, 240, 320, 240)];
[super viewDidLoad];
// Do any additional setup after loading the view.
}
Now go to secondVC .h:
#import <UIKit/UIKit.h>
#import "textViewChild.h"
#interface TextViewViewController : UIViewController<textViewChildDelegate>{
UITextView * myfirstTextView;
}
#end
and to .m file:
#import "TextViewViewController.h"
#implementation TextViewViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)getStrings:(NSString *)string{
myfirstTextView.text = string; // finally we get string from child view controller
}
- (void)viewDidUnload
{
myfirstTextView = [[UITextView alloc]init];
[super viewDidUnload];
// Release any retained subviews of the main view.
}