I have a viewController called "chooseDateViewController" where in the .m file it takes input from the user and puts into a string. I have another viewController called "showTable" where I have a custom made table that takes the dates in the string. the table is generated (in showTable.m) based on the dates (which are strings).
I want to be able to call "showTableViewController" view controller when the user enters the data and presses a button so then they are taken to the showTableViewController with there dates nicely displayed but my problem is I cannot pass the data from the "chooseDate" View controller to a method in "showTable". This is how I did it but it is not working... I tried to NSLog it but its not even entering the function. If anyone knows why, it would be much appreciated.
Thanks
// In chooseDateViewController.m
-(void) sendValue {
NSString *date= #"July 25 2012";
UIViewController *view5 = [[showTableViewController alloc] initWithNibName:#"showTableViewController" bundle:nil];
[self.navigationController pushViewController:view5 animated:YES];
[view5 receiveNumbers:date]; //trigger the method in showTable.m
[view5 release];
}
// showTableViewController.m
-(void) receiveNumbers: (id) sender {
NSLog (#"data received is %#", sender);
}
Perhaps you can initialize the viewController with the information, so for example, you can have a line that is like:
UIViewController *view5 = [[showTableViewController alloc] initWithSomeInfo: (the structure that houses the data)];
Then in the custom init method of the showTableViewController, you can process the data before you are pushing the view controller.
I hope this helps,
Tams
Here is some code that you were looking for:
In the showTableViewController, you have have a variable to hold the passed in information so:
- (id)initWithSomeInfo(NSArray*)info{
self = [super init];
if(self){
myOwnVariable = info;
[self processInfo:myOwnVariable];
}
return self;
}
Related
I'm making a small iPad APP using the SplitViewController and I mainly working with MasterViewController on the DetailViewController. I am trying to Push some data from the DetailViewController to MasterViewController. once the information is pushed to the MasterViewController I want to make use of it so to do this im using a pop method.
The push method populates the array- but for some reason my array is recreated every time i call the pushModuleTitle method and it only hold one object at a time.
In the DetailViewController.m
- (IBAction)buttonAddPressed:(id)sender
{
cw3MasterViewController *master = [[cw3MasterViewController alloc]init];
[moduleTitles addObject:textFieldModuleTitle.text];
[master pushModuleTitle:self.textFieldModuleTitle.text];);
}
In the MasterViewController.m
- (NSMutableArray *)moduleTitleStack//init array
{
if (!_moduleTitleStack){
_moduleTitleStack = [[NSMutableArray alloc] init];
}
return _moduleTitleStack;
}
-(void)pushModuleTitle:(NSString*)moduleTitile
{
NSString * moduleTitileObject = moduleTitile;
[self.moduleTitleStack addObject:moduleTitileObject];
NSLog(#"%#",self.moduleTitleStack);
}
so to use the information pushed I'm using this pop method: - But this alway returns me a null value and when I put a break point it indicates that my moduleTitleStack has 0 objects. I'm not sure why.
-(NSString *)popModuleTitle
{
NSString * moduleTitileObject = [self.moduleTitleStack lastObject];
if (moduleTitileObject)[self.moduleTitleStack removeLastObject];
return moduleTitileObject;
}
calling the popModuleTitle method: Gives a null value
- (IBAction)testButtonPressed:(id)sender {
NSLog(#"%#", [self popModuleTitle]);
}
The reason is the same as the answer to the other question you just asked. You are creating a new instance of cw3MasterViewController every time you click the button. You should get a reference to the master controller like this:
cw3MasterViewController *master = self.splitViewController.viewControllers[0];
This assumes that master is the only controller at index 0 of the split view controller. If it's embedded in a navigation controller (which it often is), then you would need to go a little further to get to master:
cw3MasterViewController *master = (cw3MasterViewController *)[(UINavigationController *) self.splitViewController.viewControllers[0] topViewController];
ere :
w3MasterViewController *master = (cw3MasterViewController *)[(UINavigationController *) self.splitViewController.viewControllers[0] topViewController];
you have a Semantic Issue: Subscript requires size of interface 'NSArray', which is not constant in non-fragile ABI
Use Delegation instead !
This has been bugging me all night, It doesn't make any sense. This function returns whatever it's supposed to. EG, the issueName.
-(id)initWithIssue:(NSString *)string {
self = [super initWithNibName:nil bundle:nil];
if (self) {
NSString *thing = string;
issueName = [[NSString alloc]initWithString:thing];
NSLog(#"The issue name = %#", issueName);
}
return self;
}
However if I try to access 'issueName' in the viewDidLoad: nothing, it's equal to null no matter what I do. I've tried cleaning, setting a custom setter, switching between a property or a Ivar... ect. What's so infuriating is that this string just disappears at this point in the programe.
What the hell is going on, this is infuriating.
Edit
This the the entire code that is relevant. And how I started off.
Dot h file:
#interface BFPaidAreaViewController : UITabBarController <BFNewsTableViewControllerDelegate> {
NSString *issueName;
}
-(id)initWithIssue:(NSString *)string;
Dot m file:
-(id)initWithIssue:(NSString *)string {
self = [super init];
if (self) {
// PLPiper I had it that way before, because I was fiddling out of frustration
issueName = [[NSString alloc] initWithString:string];
NSLog(#"This is Called, the issue name is equal to = %#", issueName);
}
return self;
}
-(void)viewDidLoad {
[super viewDidLoad];
NSLog(#"The issue = %#", issueName);
}
I'm calling the view controller like so:
BFPaidAreaViewController *pavc = [[BFPaidAreaViewController alloc]initWithIssue:#"test"];
This will log:
This is Called, the issue name is equal to = test
The issue = (null)
New Edit
Found the problem. It's a UITableViewController. Strange, when I change it's class to a UIViewController it works. Is this a bug or just normal behaviour? But more pressing, how to I get round this limitation?
(Just to explain what I've done UI wise, the UITabBarController is in a modal View. This works fine with a UIViewController.)
God Awful Fix
-(id)initWithIssue:(NSString *)string {
self = [super initWithNibName:nil bundle:nil];
if (self) {
NSString *thing = string;
issueName = [[NSString alloc]initWithString:thing];
NSLog(#"The issue name = %#", issueName);
}
[self viewDidLoad];
return self;
}
Makes me feel dirty. But it will have to do for now, I can continue. If anyone can think of a solution please tell. Sorry about my feistiness, it was incredibly frustrating listening to people say, 'what the hell is this?? what is issueName?? an ivar??' when it was really implicit in the question.
Okay, first of all, replace:
self = [super initWithNibName:nil bundle:nil]; // Unneeded nil arguments
with:
self = [super init]; // Equivalent method, less processing involved.
Secondly, replace:
NSString *thing = string;
issueName = [[NSString alloc]initWithString:thing];
with just:
_issueName = [[NSString alloc] initWithString:string];
If issueName is a property (and you haven't #sythesized it to anything else) its representation should be _issueName.
The above fixes are more or less just make the code more succinct. The issue is probably with the code in viewDidLoad: (See below).
Now you can initialise your Issue object, and use the following code to display the issue name:
// Init:
Issue *myIssue = [[Issue alloc] initWithIssue:#"Example Issue"];
// Log:
NSLog(#"%#", myIssue.issueName);
And the log should show:
Example Issue
can you try this:
make the issueName a property, like
#property (strong, nonatomic) NSString *issueName;
then use it like this,
-(id)initWithIssue:(NSString *)string {
self = [super initWithNibName:nil bundle:nil];
if (self) {
NSLog(#"The string = %#", string);
self.issueName = string;
NSLog(#"The issue name = %#", issueName);
}
return self;
}
if you are using the automated synthetized property (i.e not declaring the #synthentize manually for the issueName), then your iVar will be called _issueName instead of issueName
what do you get from the above code ?
I find this somewhat curious. You call [super initWithNibName:nil bundle:nil]. This leads me to believe that this might be a subclass of NSViewController. If you init an NSViewController like this, barring some other, pretty non-standard stuff, -viewDidLoad probably won't get called because there's no NIB to be loaded (because you passed nil to super). But clearly you're setting a breakpoint in -viewDidLoad so it's getting called (on something). This makes me think that you have this class specified in a XIB somewhere as a File's Owner or as a NIB-loaded custom object. If that's the case, it leads me to believe that the instance you're init-ing and the instance on which -viewDidLoad is being called aren't the same instance. You can confirm this for yourself by putting NSLog(#"self: %p", self); in each method and seeing whether they are the same or different.
If the instance that is getting a call to -viewDidLoad is NIB-loaded, then your init method won't be called. Instead it will use -initWithCoder
If you can elaborate on the situation here (i.e. how this is getting instantiated, are there any XIBs involved, etc), I will edit my answer to provide more help, but I don't think there's enough information here to be truly helpful.
I feel your frustration. Assuming standard behavior, any of the suggestions here should have worked. This only reinforces my suspicion that these are not the same instance (between -initWithIssue and -viewDidLoad.
AAA.m:
- (void)keepCurrentArray:(id)object
{
_currentTest=[[NSMutableArray alloc]init];
[_currentTest addObject:#"one"];
[_currentTest addObject:#"two"];
[_currentTest addObject:object];
NSLog(#"My Array is:%#",_currentTest);
}
Class BBB.m is passing objects to class AAA.
Right now if i'm passing X to the above method so the array will be: one,two,X . Then i'll send it Y and the array will be one,two,Y instead of what i want to accomplish: one,two,x,one,two,y.
Is that because I'm alloc and init _currentTest every time? How can I solve it?
Update:
I had a few suggestions on how to solve this and none of them worked for me. I've created a new project with just the code in the answers and i'm still getting the same result when I try to add the second object i get: one, two, test instead of one,two,test,one,two,test
Yes, it's because that you're alloc and init-ing every time you run that method. Instead, put _currentTest = [[NSMutableArray alloc] init]; in AAA.m's init method.
AAA.m
-(id)init
{
if ((self = [super init]))
_currentTest = [[NSMutableArray alloc] init];
return self;
}
- (void)keepCurrentArray:(id)object
{
[_currentTest addObject:#"one"];
[_currentTest addObject:#"two"];
[_currentTest addObject:object];
NSLog(#"My Array is:%#",_currentTest);
}
_currentTest=[[NSMutableArray alloc]init]; in a method is never a good thing!!!
As per naming convention it seems to be a property to the AAA Class. So for property, the alloc+init should be either in init or awakeFromNib. So that if is initialized just once.
However in some situations init is called more than once then your previous values are lost and new set are added.
So what you can do is make another class and put this _currentTest Array there and make it static and use it here. I hope this will work fine. And make sure in the init method of that class it is initialized just once, as :
//**this is not compiled and checked may contains typo and errors**
#implementation Storage
static NSMutableArray *yourStaticArray;
-(id)init{
self = [super init];
if (self) {
if (!yourStaticArray) {
yourStaticArray=[NSMutableArray new];
}
}
return self;
}
-(void)addYourStaticArray:(NSString *)val{
[yourStaticArray addObject:val];
}
-(NSArray *)yourStaticArray {
return yourStaticArray ;
}
#end
Well you need to have a property for that _currentTest if you want to be able to keep it around between method call.
Put this in your .h file
#property (nonatomic, copy) NSMutableArray * currentTest;
And this in hour .m file
- (NSMutableArray *)currentTest
{
if (!_currentTest)
_currentTest = [[NSMutableArray alloc] initWithCapacity:11];
return _currentTest;
}
- (void)keepCurrentArray:(id)object
{
[self.currentTest addObject:#"one"];
[self.currentTest addObject:#"two"];
[self.currentTest addObject:object];
NSLog(#"My Array is:%#", self.currentTest);
}
I Just try the code you've put on drop box and it's working exactly as it is suppose to, the array keeps it's value and everything,
BUT
Exactly as it is suppose to is not what you are trying to achieve
Your problem is not in AAA.m, your problem is in BBB.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
ViewController *kios = [ViewController new];
[kios keepCurrentArray:#"Test"];
[kios keepCurrentArray:#"Test2"];
}
I took the liberty of adding the #"test2" to the code you've send. If you run it you will see that your array still exist when the second call is made.
The REAL problem here is that you are creating a NEW ViewController each time. A brand new one, it is normal that it is empty (clean), it's a new one.
If I buy a note pad monday and fill it up, I don't expect when I'm buying an other one on friday to be already fill with the stuff I've wrote on monday in the previous one.
But this is exactly that behaviour that you are expecting from your ViewController.
You need to store your NSMutableArray in an other object that doesn't
get destroy and created over and over again.
This is happening because you are creating a new array every time that your method is called. Basically, you need to see if it has already been created, and only create it if needed. You can change your method to:
- (void)keepCurrentArray:(id)object
{
if (!_currentTest)
{
_currentTest=[[NSMutableArray alloc]init];
}
[_currentTest addObject:#"one"];
[_currentTest addObject:#"two"];
[_currentTest addObject:object];
NSLog(#"My Array is:%#",_currentTest);
}
EDIT:
In addition to the above problem, you also have this code which needs to be corrected (comments removed):
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
ViewController *kios = [ViewController new];
[kios keepCurrentArray:#"Test"];
}
This code creates a new instance of ViewController every time that you click on a row in the table. Because you are creating a new instance instead of reusing the old one, you start with an empty array each time. In order to keep adding to the same array, you need to keep using the same view controller.
In order to do this, you need to add a declared property to your .h file, similar to your currentTest declared property:
#property (strong,nonatomic) ViewController *kios;
Then, change your action so that you only create a new view controller if needed (the first time) and then reuses it after that:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (!_kios)
{
_kios = [ViewController new];
}
[_kios keepCurrentArray:#"Test"];
}
I am writing an app which is a sort of dictionary - it presents the user with a list of terms, and when clicked on, pops up a dialog box containing the definition. The definition itself may also contain terms, which in turn the user can click on to launch another definition popup.
My main app is stored in 'myViewController.m'. It calls a custom UIView class, 'CustomUIView.m' to display the definition (this is the dialog box that pops up). This all works fine.
The text links from the CustomUIView then should be able to launch more definitions. When text is tapped in my CustomUIView, it launches another CustomUIView. The problem is, that this new CustomUIView doesn't have access to the hash map which contains all my dictionary's terms and definitions; this is only available to my main app, 'myViewController.m'.
Somehow, I need to make my hash map, dictionaryHashMap, visible to every instance of the CustomUIView class. dictionaryHashMap is created in myViewController.m when the app opens and doesn't change thereafter.
I don't wish to limit the number of CustomUIViews that can be opened at the same time (I have my reasons for doing this!), so it would be a little resource intensive to send a copy of the dictionaryHashMap to every instance of the CustomUIView. Presumably, the solution is to make dictionaryHashMap a global variable.
Some of my code:
From myViewController.m:
- (void)viewDidLoad
{
self.dictionaryHashMap = [[NSMutableDictionary alloc] init]; // initialise the dictionary hash map
//... {Code to populate dictionaryHashMap}
}
// Method to pop up a definition dialog
- (void)displayDefinition:(NSString *) term
{
NSArray* definition = [self.dictionaryHashMap objectForKey:term]; // get the definition that corresponds to the term
CustomUIView* definitionPopup = [[[CustomUIView alloc] init] autorelease]; // initialise a custom popup
[definitionPopup setTitle: term];
[definitionPopup setMessage: definition];
[definitionPopup show];
}
// Delegation for sending URL presses in CustomUIView to popupDefinition
#pragma mark - CustomUIViewDelegate
+ (void)termTextClickedOn:(CustomUIView *)customView didSelectTerm:(NSString *)term
{
myViewController *t = [[myViewController alloc] init]; // TODO: This instance has no idea what the NSDictionary is
[t displayDefinition:term];
}
From CustomUIView.m:
// Intercept clicks on links in UIWebView object
- (BOOL)webView: (UIWebView*)webView shouldStartLoadWithRequest: (NSURLRequest*)request navigationType: (UIWebViewNavigationType)navigationType {
if ( navigationType == UIWebViewNavigationTypeLinkClicked ) {
[myViewController termTextClickedOn:self didSelectTerm:request];
return NO;
}
return YES;
}
Any tips on how to make the dictionaryHashMap visible to CustomUIView would be much appreciated.
I have tried making the dictionaryHashMap global by doing the following:
Changing all instances of 'self.dictionaryHashMap' to 'dictionaryHashMap'
Adding the line 'extern NSMutableDictionary *dictionaryHashMap;' to CustomUIView.h
Adding the following outside of my implementation in myViewController.m: 'NSMutableDictionary *dictionaryHashMap = nil;'
However, the dictionaryHashMap remains invisible to CustomUIView. As far as I can tell, it actually remains a variable which is local to myViewController...
It's not resource-intensive to pass around the reference (pointer) to dictionaryHashMap. A pointer to an object is only 4 bytes. You could just pass it from your view controller to your view.
But I don't know why you even need to do that. Your view is sending a message (termTextClickedOn:didSelectTerm:) to the view controller when a term is clicked. And the view controller already has a reference to the dictionary, so it can handle the lookup. Why does the view also need a reference to the dictionary?
Anyway, if you want to make the dictionary a global, it would be more appropriate to initialize it in your app delegate, in application:didFinishLaunchingWithOptions:. You could even make the dictionary be a property of your app delegate and initialize it lazily.
UPDATE
I didn't notice until your comment that termTextClickedOn:didSelectTerm: is a class method. I assumed it was an instance method because myViewController starts with a lower-case letter, and the convention in iOS programming is that classes start with capital letters. (You make it easier to get good help when you follow the conventions!)
Here's what I'd recommend. First, rename myViewController to MyViewController (or better, DefinitionViewController).
Give it a property that references the dictionary. Whatever code creates a new instance of MyViewController is responsible for setting this property.
Give CustomUIView properties for a target and an action:
#property (nonatomic, weak) id target;
#property (nonatomic) SEL action;
Set those properties when you create the view:
- (void)displayDefinition:(NSString *)term {
NSArray* definition = [self.dictionaryHashMap objectForKey:term];
CustomUIView* definitionPopup = [[[CustomUIView alloc] init] autorelease]; // initialise a custom popup
definitionPopup.target = self;
definitionPopup.action = #selector(termWasClicked:);
...
In the view's webView:shouldStartLoadWithRequest: method, extract the term from the URL request and send it to the target/action:
- (BOOL)webView: (UIWebView*)webView shouldStartLoadWithRequest: (NSURLRequest*)request navigationType: (UIWebViewNavigationType)navigationType {
if ( navigationType == UIWebViewNavigationTypeLinkClicked ) {
NSString *term = termForURLRequest(request);
[self.target performSelector:self.action withObject:term];
return NO;
}
return YES;
}
In the view controller's termWasClicked: method, create the new view controller and set its dictionary property:
- (void)termWasClicked:(NSString *)term {
MyViewController *t = [[MyViewController alloc] init];
t.dictionary = self.dictionary;
[t displayDefinition:term];
}
Create a class that will be used as singleton. Example.
You Should always keep your data in separate class as the mvc pattern suggest and that could be achieved by using a singleton class for all your dictionary terms and accesing them from every custom view when needed.
The NSMutableArray detailsDataSource and int detailIndex is passed on to next View Controller from
MainDetailViewController.m:
#import "UsersDetailViewController.h"
...
- (void)swipeDetectedUp:(UISwipeGestureRecognizer *)sender
{
UsersDetailViewController *usersController = [[self storyboard] instantiateViewControllerWithIdentifier:#"UsersController"];
[self.navigationController pushViewController:usersController animated:NO];
usersController.usersDataSource = [[NSMutableArray alloc] initWithArray:detailsDataSource];
usersController.userDetailIndex = detailIndex;
}
Swipe through the index in UserDetailViewController.m:
- (void)swipeDetectedRight:(UISwipeGestureRecognizer *)sender
{
if (userDetailIndex != 0)
userDetailIndex--;
}
When swipeDetectedDown to pop back, MainDataViewController needs to know which object at index to display:
- (void)swipeDetectedDown:(UISwipeGestureRecognizer *)sender
{
//jump to correct object at index, same as current object at index in this view
[self.navigationController popViewControllerAnimated:NO];
}
Code suggestions?
Use NSNotificationCenter to send an object back to the MainDataViewController...
Example:
In UsersDetailViewController populate an NSDictionary with a key=>value pair then send it over to where you want it to go.
NSArray *key = [NSArray arrayWithObject:#"myIndex"];
NSArray *object = [NSArray arrayWithObject:detailIndex];
NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:object forKeys:key];
[[NSNotificationCenter defaultCenter] postNotificationName:#"MainDataViewController" object:self userInfo:dictionary];
Note: You need to setup an identifier on MainDataViewController called MainDataViewController or whatever you want to call it. Using the VC name keeps it simpler.
Then on MainDataViewController do this in the viewDidLoad() method.
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(receiveNotification:) name:#"MainDataViewController" object:nil];
And then receive the notification by using the following method:
- (void)receiveNotification:(NSNotification *) notification
{
if([[notification name] isEqualToString:#"MainDataViewController"])
{
NSDictionary *dictionary = [NSDictionary dictionaryWithDictionary:[notification userInfo]];
if([dictionary valueForKey:#"myIndex"])
{
// do whatever you need to do with the passed object here. In your case grab the detailIndex and use it for something...
}
}
}
The easy part is to put the UsersDetailViewController pointer into a property of MainDetailViewController so it can access self.usersController.usersDataSource & self.usersController.userDetailIndex later. Then the only trick is to have it know when the UsersDetailViewController was popped.
In code I used to write, I often tried something like making MainDetailViewController be a delegate of UsersDetailViewController, and having a delegate method in MainDetailViewController be called when the UsersDetailViewController want to close programmatically, and in that do both the popViewControllerAnimated: and update the MainDetailViewController's state. In other words, always have the parent's code pop the child off. This works, but not in the case where you have the child view controller pop automatically via the navigation controller's back button say, so overall I'd argue against that technique.
I think there's better solutions for having the parent's code get called when its child is popped. Perhaps implement a viewWillAppear method and if self.usersController is set there, then you know you're coming back from the UsersDetailViewController, at that point access the other controller's properties and finally clear self.usersController.