ios - Action from UITableView to a UIViewController - ios

Question

I have MainController which is the (UIViewController) main view in the app, and MenuController which is a UITableView.
In the MainController.h
- (void) menu1:(NSInteger ) row;
In the MainController.m
- (void) menu1:(NSInteger ) row{
switch(row){
case 0:
//DO SOMETHING.......
break;
default:
break;
}
}
I want "menu1" to make action when I click a cell in the MenuController.
I made this: (in MenuController.m)
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if(indexPath.section == 0){
[menu1:indexPath.row]; //<=== What should I do to make it work ?
}
}

Answer 1

You can access the method using your UINavigationController.
So in your MainController.h, add this:
- (void) menu1:(NSInteger)row;
Now in your MenuController.m:
#import "MainController.h";
and change didSelectRowAtIndexPathto:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if(indexPath.section == 0){
MainController *mC = [self.navigationController.viewControllers objectAtIndex:0]; // Change the objectAtIndex number to the number of your MainController in the navigationController view hierarchy
[mC menu1:indexPath.row];
}
}

Answer 2

Your menu1 method is an instance method on the MainController, so you'll want to send the message to an instance of that class. Like so:
MainController *mainVC = [[MainController alloc] init];
[mainVC menu1:indexPath.row];
Or, if you were to define your menu1 method as a class method, you could just send the message to the MainController without initializing. Use plusses instead of minuses when defining your menu1 method, then call like this:
[MainController menu1:indexPath.row];
However, this probably isn't the best way for you to pass data back and forth between View Controllers. You'll likely want to at the very least set a property on your MenuController, and then send the message to that (of course, setting the property wherever it makes sense).
[self.mainController menu1:indexPath.row];
But another really good method for calling a method on another View Controller is the delegate pattern, but I'll leave that up to you to research on your own.
https://developer.apple.com/library/ios/documentation/General/Conceptual/DevPedia-CocoaCore/Delegation.html

Answer 3

in your MenuController.h
You get back to your previous view like this.
[[self navigationController] popToViewController:yourController animated:YES];
or
[self.navigationController popToRootViewControllerAnimated:animated];
and use UINotificationCenter or Delegate pattern.
If you have no idea about them UINoitifcation is easier but Delegate pattern is better in this situation. I ll explain how to use UINotificationCenter.
Throw notification from your menuController like this.
[[NSNotificationCenter defaultCenter]
postNotificationName:#"yourNotificationName"
object:nil ];
This code is for catch notification write it down to your viewappear method.
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(yourMethodAboutWhatYouWantToDoAfterCatchNotification:)
name:#"yourNotificationName"
object:nil ];
Do what you want to do after catch it
- (void) yourMethodAboutWhatYouWantToDoAfterCatchNotification:(NSNotification *) notification
{
// do your job.
}
And in viewDidDisappear remove it. Or you can catch it multiple times after time.
[[NSNotificationCenter defaultCenter] removeObserver:self name:#"yourNOtificationName" object:nil];

Answer 4

There are two ways to achieve this.
Implement a protocol, whose implementation should be there in MainController.m
In that implementation, you should call the method which you have in MainController.m.
Set the table views delegate to MainController instead of setting it as self (MenuController)
This will help to implement the delegate methods directly in the MainController.m, from which the menu1 method can be called.
Provided code below for the first way:
Create a protocol file, which will help to make a callback, and create a method.
//
// utilProtocol.h
// tempProject
//
#protocol utilProtocol <NSObject>
#optional
-(void)captureCellSelectForRow:(int)rowNumber;
#end
Now Import this file inside in MenuController.
#import "utilProtocol.h" // Inside MenuController
And create a variable for the protocol.
#property(readwrite,assign)id<utilProtocol>utilDelegate;
In MainController.h, Import the utilProtocol.h and have its delegate into it.
Don't forget to add utilProtocol
#import <UIKit/UIKit.h>
#import "utilProtocol.h"
#interface ViewController : UIViewController <utilProtocol>
#end
Now Implement the method in MainController.m
-(void)captureCellSelectForRow:(int)rowNumber
{
[menu1:rowNumber];
}
Also set the delegate for it when the tableVIew's object is created in MainController.m
[tableViewObject setUtilDelegate:self];
Now when ever didSelectRowAtIndexPath is called in MenuController, just call the method using protocol.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if(indexPath.section == 0){
[utilDelegate captureCellSelectedForRow:indexPath.row];
}
}
Using this, the method inside MainController can be called.