How to push from a UITableViewController to a UIViewController using NSDictionary? - ios

Question

I have tried to push to a UIViewController using an Array:
self.cities=#[#"New York", #"Chicago", #"Los Angeles", #"Miami"];
and then in my didSelectRowAtIndexPath:
[self.navigationController pushViewController:NewYorkViewController animated:YES];
but now all the items in the array push to NewYorkViewController. I believe an NSDictionary would work
NSDictionary *cities=#[#{#"city":#"NewYork",#"viewController":NewYorkViewController}, #{#"city":#"Chicago",#"viewController":ChicagoViewController}, #{#"city":#"LosAngeles",#"viewController":LosAngelesViewController}, #{#"city":#"Miami",#"viewController":MiamiViewController}];
However I'm a noob and have never worked with NSDictionary. If you would be so kind to explain how i would go about doing this. If you know a way using array's that would work too.
ps.
I don't use storyboards and could you also explain what I would do in my cellForRowAtIndexPath: and numberOfRowsInSection:
Thanks

Answer 1

I am guessing you want to transfer your data from the UITableViewController to NewYorkViewController. The usual way to do this is having a property in your NewYorkViewController say an array or whatver you want.
#property (nonatomic,retain) NSMutableArray *itemsArray;
and in didSelectRowAtIndexPath while creating NewYorkViewController's object
NewYorkViewController *newyorkObject = [NewYorkViewController alloc]init];
newyorkObject.itemsArray = self.cities;
[self.navigationController pushViewController:newyorkObject animated:YES];
and in viewDidLoad of NewYorkViewController add this:
NSLog(#"items array: %#",self.itemsArray); //to check whether you got what you passed from the previous class.

Answer 2

I am using the Windows System now, so the following code may contain errors.
Use reflection to get the IOS Class
And then use this to alloc an object and operate it
You can use [Object class] or NSClassFromString ("Class Name") to get type of class
like this:
NSString * ClassName = # "yourClassName";
Class * tempClass = NSClassFromString (ClassName);
//if your class is subclass of UIViewController
UIViewController * tempObj = [[tempClass alloc] init];
//operating it
[self.navigationController pushViewController: tempObj animated:YES];
[tempObj release];
For your code you can change it like this:
//NSDictionary =#{#"key",#"value",....}
NSDictionary *citieone=#{#"NewYork",[NewYorkViewController Class]}
NSDictionary *citietwo = #{#"Chicago",NSClassFromString(#"ChicagoViewController")};
//other citys
NSArray* cities = #{citieone,citietwo,...};
//in UITableView
NSString* cityName = [[[citis objectForIndex:index] allKeys] objectAtIndex:0];
Class* controllerClass = [[[citis objectForIndex:index] allValues] objectAtIndex:0];
// operating it
UIViewController * controller= [[controllerClass alloc] init];
[self.navigationController pushViewController: controller animated:YES];
[controller release];

Answer 3

I did something similar with my app, but I was using NSArray instead of NSDictionary, but the logic is similar IMHO.
I created a NSArray with my objects, and a method to return their count and also the name at index. This is so that when I want to get a particular object from the array I can access it quicky. I have changed my code to accept the NSDictionary so that you can use.
In order to create the number of rows in the UITableView, I created a method that returns the number of rows when called.
-(NSInteger) numberOfCities
{
NSArray * allKeys = [mutableDictionary allKeys];
return [allKeys count];
}
This will be called in the
- (NSInteger) tableView: (UITableView*) tableView numberOfRowsInSection: (NSInteger) section
{
return [self numberOfCities];
}
so that the UITableView will have the exact number of rows as the NSDictionary
In order to return the name at a particular index so that you can display that name in the UITableViewCell, I created this method
-(NSString*) cityNameAtIndex: (NSInteger) index
{
return NSString* cityName = [[[mutableDictionary objectForIndex:index] allKeys] objectAtIndex:index]; ;
}
This method can be called in the
- (UITableViewCell*) tableView: (UITableView*) tableView cellForRowAtIndexPath: (NSIndexPath*) indexPath
to assign the different city names to different cells in the table.
Then in the delegate
- (void) tableView: (UITableView*) tableView didSelectRowAtIndexPath: (NSIndexPath*) indexPath
you can call this method and push to the different viewControllers
UIViewController* selectedController = nil ;
NSString* nameOfCity = [self cityNameAtIndex: indexPath.row] ;
if( [nameOfCity isEqualToString:#"New York"] )
selectedController = [[NewYorkViewController alloc] init];
else if( [nameOfCity isEqualToString:#"Chicago"] )
selectedController = [[ChicagoViewController alloc] init];
else if( [nameOfCity isEqualToString:#"Miami"] )
selectedController = [[MiamiViewController alloc] init];
else if( [nameOfCity isEqualToString:#"Los Angeles"] )
selectedController = [[LosAngelesViewController alloc] init];
To do this, you will have to create the different viewControllers (Chicago, New York, Los Angeles, Miami) beforehand, but if you have already created them and left them as an object in the NSDictionary, you can use the nameOfCity to grab the viewController object within the NSDictionary that belongs to that city, and then assign the selectedController to that viewController.
But if you are only using the NSDictionary to store the names of the cities, I think that NSArray will be a better option. I created mine in the appDelegate and the names within the NSArray are #define in my class called global.h as I needed the NSArray and names in many different viewControllers, so if you need that as well, you can do the same.
Hope this helps! :)