multiple view controllers involved, how to send a value back to starting view controller?

Question

I am very new to iOS and overwhelmed with resources I find online. My use case is simple

a.) ViewController parent has label called categoryLabel. A tap on label category opens a new view View 1
b.) View 1, shows all groups. Lets says A, B, C. This will be shown on table
c.) when user click on any group A, B or C, a new view View 2 appears with all categories in that group. For example, user clicks on A and on View 2 user sees categories A1, A2, A3. d.) Now when user clicks on any specific category, how does that goes back to ViewController parent and assigns to categoryLabel?

I do not know what is the best way to approach this design. Any guidance is very much appreciated

Answer 1

hope this will help

let take an example , your are going from A -> B and want send some data from B to A , there are many technique to do that but using delegate method and block are nicer way.

delegate way :-

in your B.h file

@protocol yourDelegate <NSObject>

-(void)whichCategoryClicked:(NSString *)categoryName;

@end

@interface B : UIView
@property(nonatomic, assign)id<yourDelegate> delegate;

in your B.m

just call this delegate method after Clicking particular category.

[self.delegate whichCategoryClicked :@"Category_name"];

in your A.h

assign it as delegate and import the above class

@interface A.h : UIViewController<yourDelegate>

and in Implement this method in A.m

first in your viewdidload

{

---

 B *objB = [[B alloc]init];
    objB.delegate = self;

---

}

-(void)whichCategoryClicked:(NSString *)categoryName
{
categoryLabel.text = categoryName;
}