Information on pushing to new DetailView [duplicate]

Question

This question already has answers here:

Passing data between view controllers (44 answers)

Closed 9 years ago.

Does anyone know of any tutorials out there that explains how to push to new details views. Right now I have 2 TableViews, the first TableView holds states and the second TableView holds area names. From the second TableView I want to be able to press an area and display information in the DetailView, but I'm not sure as to how to get that information to the DetailView.

RootTableViewController.h

#import <UIKit/UIKit.h>

@interface RootTableViewController : UITableViewController

@end

RootTableViewController.m

#import "RootTableViewController.h"
#import "SecondTableViewController.h"

@interface RootTableViewController ()

@end

@implementation RootTableViewController
{
NSMutableArray *states;
}

- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
    // Custom initialization
}
return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];

states = [NSMutableArray arrayWithObjects:@"Alabama", @"Georgia", @"Tennessee", nil];

// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;

// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [states count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = @"StatesCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];

if(cell == nil)
{
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}

cell.textLabel.text = [states objectAtIndex:indexPath.row];
return cell;
}

SecondTableViewController.h

#import <UIKit/UIKit.h>

@interface SecondTableViewController : UITableViewController
{
NSMutableArray *listOfStates;
}
@property (retain, atomic) NSMutableArray *listOfStates;
@property (nonatomic, strong) NSString *stateName;

@end

SecondTableViewController.m

#import "SecondTableViewController.h"
#import "RootTableViewController.h"

@interface SecondTableViewController ()

@end

@implementation SecondTableViewController

@synthesize listOfStates = _listOfStates;

- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
    // Custom initialization
}
return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];

_listOfStates = [NSDictionary dictionary];


_listOfStates  =
@{
@"Alabama":@[
        @{@"area":@"albama area 1", @"description":@"Alabama specs 1"},
        @{@"area":@"albama area 2", @"description":@"Alabama specs 2"},
        @{@"area":@"albama area 3", @"description":@"Alabama specs 3"},
        ],
@"Georgia":@[
        @{@"area":@"Georgia area 1", @"description":@"Georgia specs 1"},
        @{@"area":@"Georgia area 2", @"description":@"Georgia specs 2"},
        @{@"area":@"Georgia area 3", @"description":@"Georgia specs 3"}
        ],
@"Tennessee":@[
        @{@"area":@"Tennessee area 1", @"description":@"Tennessee specs 1"},
        @{@"area":@"Tennessee area 2", @"description":@"Tennessee specs 2"},
        @{@"area":@"Tennessee area 3", @"description":@"Tennessee specs 3"}
        ]

};

NSArray *state = [_listOfStates objectForKey:_stateName];

// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;

// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [self.state count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath    *)indexPath
{
static NSString *simpleTableIdentifier = @"Animal2Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
cell.textLabel.text = [[self.state objectAtIndex:indexPath.row] objectForkey:@"area"];

return cell;
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self performSegueWithIdentifier:@"detailSegue" sender:sender];
}

#pragma mark - Navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Make sure your segue name in storyboard is the same as this line
if ([[segue identifier] isEqualToString:@"detailSegue"])
{
    //get the specs
    NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
    NSString *specs = [_informationSpecs objectAtIndex:indexPath.row];

    //set the specs
    DetailViewController *detailVC= (DetailViewController *)segue.destinationViewController;
    detailVC.description= [[self.state objectAtIndex:indexPath.row] objectForkey:@"description"];
}
}

@end

Errors

SecondTableViewController.m:43:10: Expected ':'

SecondTableViewController.m:58:37: No visible @interface for 'NSDictionary' declares the selector 'obejectForKey:'

SecondTableViewController.m:67:9: Use of undeclared identifier 'didReceiveMemoryWarning'

Thanks for any guidance.

Answer 1

Instead of having array for each state you should put data together because they are related.

List of States:

_listOfStates  =
@{
  @"Alabama":@[
            @{@"area":@"albama area 1", @"description":@"Alabama specs 1"},
            @{@"area":@"albama area 2", @"description":@"Alabama specs 2"},
            @{@"area":@"albama area 3", @"description":@"Alabama specs 3"},
            ],
  @"Georgia":@[
            @{@"area":@"Georgia area 1", @"description":@"Georgia specs 1"},
            @{@"area":@"Georgia area 2", @"description":@"Georgia specs 2"},
            @{@"area":@"Georgia area 3", @"description":@"Georgia specs 3"}
            ],
  @"Tennessee":@[
            @{@"area":@"Tennessee area 1", @"description":@"Tennessee specs 1"},
            @{@"area":@"Tennessee area 2", @"description":@"Tennessee specs 2"},
            @{@"area":@"Tennessee area 3", @"description":@"Tennessee specs 3"}
            ]

  };

State Array:

self.state = [_listOfStates objectForKey:_stateName];

numberOfRowsInSection

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self.state count];
}

cellForRowAtIndexPath

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"Animal2Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    cell.textLabel.text = [[self.state objectAtIndex:indexPath.row] objectForkey:@"area"];

    return cell;
}

didSelectRowAtIndexPath

 -(void)tableView:(UITableView *)tableView 
                            didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
   [self performSegueWithIdentifier:@"detailSegue" sender:sender];
 }

prepareForSegue

 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Make sure your segue name in storyboard is the same as this line
    if ([[segue identifier] isEqualToString:@"detailSegue"])
    {  
       //get the specs
       NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
       NSString *description = [[self.state objectAtIndex:indexPath.row] objectForkey:@"description"];

       //set the specs
       DetailViewController *detailVC= (DetailViewController *)segue.destinationViewController;
       detailVC.description= description;
    }
}

DEMO PROJECT

Answer 2

Implement a method in your detail view, that receives the changed data and updates local variables, if any, accordingly and updates the view. Call that method from your master view controller.