Call method from another view, I think? - objective-c

Question

I have a simple utility app, with a MainViewController.m & h and a FlipsideViewController.m & h. Within my storyboard I have a button on MainViewController. I want to be able to click the button and run a method in FlipsideViewController.m is this possible? this is my first app and I am a total novice. all comments / suggestion welcome.
enter code here
i have this in my FlipsideViewController.m this is what i want to call when i click the button.
- (void)SaveFPQData
{
NSLog(#"Data Saved");
}
and this is what i have in MainViewController.m
- (IBAction)saveButton:(id)sender
{
}
This is the code I have so far;
MainViewController.h
#import "FlipsideViewController.h"
#import "sqlite3.h"
#import "FPQCheck.h"
#interface MainViewController : UIViewController <FlipsideViewControllerDelegate>
#property (weak, nonatomic) IBOutlet UITextField *nameField;
#property (weak, nonatomic) IBOutlet UITextField *checkField;
#property (weak, nonatomic) IBOutlet UITextField *commentsField;
#property (weak, nonatomic) FlipsideViewController *flipsidecontroller;
- (IBAction)saveButton:(id)sender;
- (IBAction)showHistoryButton:(id)sender;
#end
MainViewController.m
#import "MainViewController.h"
#import "FlipsideViewController.h"
#import "sqlite3.h"
#interface MainViewController ()
#end
#implementation MainViewController
- (void)viewDidLoad
{
[super viewDidLoad];
}
// Do any additional setup after loading the view, typically from a nib.
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Flipside View
- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller
{
[self dismissViewControllerAnimated:YES completion:nil];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showAlternate"]) {
[[segue destinationViewController] setDelegate:self];
}
}
- (IBAction)saveButton:(id)sender
{
[self.flipsidecontroller SaveFPQData];
//[[NSNotificationCenter defaultCenter] postNotificationName:#"SaveFPQData" object:nil];
}
- (IBAction)showHistoryButton:(id)sender
{
}
#end
FlipSideViewController.h
#import <UIKit/UIKit.h>
#import "FPQCheck.h"
#class FlipsideViewController;
#protocol FlipsideViewControllerDelegate
- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller;
#end
#interface FlipsideViewController : UIViewController <UITableViewDelegate, UITableViewDataSource>
#property (weak, nonatomic) IBOutlet UITableView *myTableView;
#property (weak, nonatomic) id <FlipsideViewControllerDelegate> delegate;
-(void)SaveFPQData;
- (IBAction)done:(id)sender;
- (IBAction)deleteEntry:(id)sender;
#end
FlipSideViewController.m
#import "FlipsideViewController.h"
#import "MainViewController.h"
#interface FlipsideViewController ()
{
NSMutableArray *arrayOfCheck;
sqlite3 *fpqDB;
NSString *dbPathString;
}
#end
#implementation FlipsideViewController
- (void)viewDidLoad
{
/*
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(SaveFPQData)
name:#"SaveFPQData"
object:nil];
*/
[super viewDidLoad];
arrayOfCheck = [[NSMutableArray alloc]init];
[self creatOrOpenDB];
[[self myTableView]setDelegate:self];
[[self myTableView]setDataSource:self];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)SaveFPQData
{
NSLog(#"Data Saved");
}
-(void)creatOrOpenDB
{
NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
NSString *docPath = [path objectAtIndex:0];
dbPathString = [docPath stringByAppendingPathComponent:#"FPQ.db"];
char *error;
NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:dbPathString]) {
const char *dbPath = [dbPathString UTF8String];
//create db
if (sqlite3_open(dbPath, &fpqDB)==SQLITE_OK) {
const char *sql_stmt = "CREATE TABLE IF NOT EXISTS FPQ (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, CHECK INTEGER, COMMENTS TEXT)";
sqlite3_exec(fpqDB, sql_stmt, NULL, NULL, &error);
sqlite3_close(fpqDB);
}
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Actions
- (IBAction)done:(id)sender
{
[self.delegate flipsideViewControllerDidFinish:self];}
- (IBAction)deleteEntry:(id)sender {
}
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [arrayOfCheck count];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell){
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
FPQCheck *fpqCheck = [arrayOfCheck objectAtIndex:indexPath.row];
NSString *nameANDcheck = [NSString stringWithFormat:#"%#%d", fpqCheck.name, fpqCheck.check];
cell.textLabel.text = nameANDcheck;
cell.detailTextLabel.text = fpqCheck.comments;
return cell;
}
#end

Answer 1

You have mainly two ways:
add a property (eg. self.flipSideController) to your MainViewController to store a reference to the FlipsideViewController; then call SaveFPQData though it (eg. [self.flipSideController SaveFPQData]; or
use notification center to post a notification from saveButton: that triggers SaveFPQData; this would go like this:
//-- in flipsidecontroller `viewDidLoad`:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(SaveFPQData)
name:#"SaveFPQData"
object:nil];
//-- in saveButton:
[[NSNotificationCenter defaultCenter] postNotificationName:#"SaveFPQData" object:nil];
The second method is the simplest to implement, IMO, and it allows for the loosest coupling, at the expense of some clock cycles.
EDIT:
It is not entirely clear to me what you are trying to do (specifically, I don't understand fully how you can push the button in MainViewController once you FlipsideViewController is displayed; on the other hand, if you do not segue to the FlipsideViewController, then it is not there, so you cannot send a message to it), anyway you could try and initialise your self.flipsideViewController property in prepareForSegue:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showAlternate"]) {
UIViewController* controller = [segue destinationViewController];
[controller setDelegate:self];
if ([controller isKindOfClass:[FlipsideViewController class]])
self.flipsideViewController = (id)controller;
}
}
after doing that, your MainViewController will be able to send the saveFPQ message to the FlipsideViewController.
If you mean you would like to send the saveFPQ message before segue-ing to the FlipsideViewController, you should make the saveButton segue to it and the call the saveFPQ method.
What I suspect is you need some kind of "model" object accessible both from the main view and the flipside view controller.
Hope this helps.