Edit:
Thanks #BlackFrog. I think I'm nearer now, but the values are still not get getting through...
The values are set as shown by logs within [progressController updateProgressSummary:...] but are nil when I log them in progressUpdate initWithProgressUpdate:.... as shown below.
I'm slightly confused over which property is used the one set for progressUpdate or the ones set for each of the 3 components of progressUpdate. I have changed the 3 individual properties from assign to retain as suggested and have also tried doing the same with the overall progressUpdate property too (not shown here).
progressController.h
......
#property (nonatomic, assign) ProgressUpdate *progressUpdate;
progressController.m
// Ask delegate to update and display Progress text
-(void) updateProgressSummary:(NSString *)summary detail:(NSString *)detail percentComplete:(NSNumber *)complete {
// These report the proper values
DLog(#"Reporting Summary - %s", [summary UTF8String]);
DLog(#"Reporting Detail - %s", [detail UTF8String]);
DLog(#"Reporting Complete - %i", [complete intValue]);
if (summary != nil)
self.progressUpdate.summaryText = summary;
self.progressUpdate.detailText = detail;
self.progressUpdate.percentComplete = complete;
ProgressUpdate *progressUpdateForIssue = [[ProgressUpdate alloc] initWithProgressUpdate:progressUpdate];
[self.delegate performSelectorOnMainThread:#selector(displayProgress:) withObject:progressUpdateForIssue waitUntilDone:NO];
[progressUpdateForIssue release];
}
But then a few milliseconds later...., inside the object....they're nil.
progressUpdate.h
.....
#property (nonatomic, retain) NSString *summaryText;
#property (nonatomic, retain) NSString *detailText;
#property (nonatomic, retain) NSNumber *percentComplete;
progressUpdate.m
-(id) initWithProgressUpdate:(ProgressUpdate *)update {
if ((self = [super init])) {
summaryText = [update.summaryText copy];
detailText = [update.detailText copy];
percentComplete = [[NSNumber alloc] initWithFloat:[update.percentComplete floatValue]];
}
// These report nil values
DLog(#"Reporting in progUpdate summaryText - %s", [summaryText UTF8String]);
DLog(#"Reporting in progUpdate detailText - %s", [detailText UTF8String]);
DLog(#"Reporting in progUpdate percentComplete - %i", [percentComplete intValue]);
return self;
}
end of update
I need some help with passing data in a custom class from one thread to another. Its there before the pass but then disappears upon arrival. I've tried everything I know, but to no avail.
My background thread calls ProgressController and passes it details of the current progress. That in turn does performSelectorOnMainThread on ProgressController's delegate (the view controller) to display the details.
It was all working fine when I was passing through a single NSString, but I need to pass two strings and a number and as performSelectorOnMainThread can only pass one object, I have encapsulated these in a custom object - ProgressUpdate.
The data gets through to ProgressController correctly but is null by the time that it appears in the View Controller. I know this as I've put NSLogs in various places.
I wonder if its to do with:
multithreading and custom objects
the fact that ProgressController is a singleton, which is why I have then alloc'd a new ProgressUpdate each time its called, but that has not helped.
Any ideas welcome. For clarity, the code is below.
ProgressUpdate.h
#import <Foundation/Foundation.h>
#interface ProgressUpdate : NSObject {
NSString *summaryText;
NSString *detailText;
NSNumber *percentComplete;
}
#property (nonatomic, assign) NSString *summaryText;
#property (nonatomic, assign) NSString *detailText;
#property (nonatomic, assign) NSNumber *percentComplete;
-(id) initWith:(ProgressUpdate *)update;
#end
ProgressUpdate.m
#import "ProgressUpdate.h"
#implementation ProgressUpdate
#synthesize summaryText, detailText, percentComplete;
-(id) initWith:(ProgressUpdate *)update {
self = [super init];
self.summaryText = update.summaryText;
self.detailText = update.detailText;
self.percentComplete = update.percentComplete;
return self;
}
#end
ProgressController.m
static ProgressController *sharedInstance;
+ (ProgressController *)sharedInstance {
#synchronized(self) {
if (!sharedInstance)
[[ProgressController alloc] init];
}
return sharedInstance;
}
+(id)alloc {
#synchronized(self) {
NSAssert(sharedInstance == nil, NSLocalizedString(#"Attempted to allocate a second instance of a singleton ProgressController.", #"Attempted to allocate a second instance of a singleton ProgressController."));
sharedInstance = [super alloc];
}
return sharedInstance;
}
-(id) init {
if (self = [super init]) {
[self open];
}
return self;
}
.........
// Ask delegate to update and display Progress text
-(void) updateProgressSummary:(NSString *)summary detail:(NSString *)detail percentComplete:(NSNumber *)complete {
if (summary != nil)
self.progressUpdate.summaryText = summary;
self.progressUpdate.detailText = detail;
self.progressUpdate.percentComplete = complete;
ProgressUpdate *progressUpdateForIssue = [[ProgressUpdate alloc] initWith:progressUpdate];
[self.delegate performSelectorOnMainThread:#selector(displayProgress:) withObject:progressUpdateForIssue waitUntilDone:NO];
[progressUpdateForIssue release];
}
RootViewController.m
// Delegate method to display specific text in Progress label
- (void) displayProgress:(ProgressUpdate *)update {
[progressSummaryLabel setText:update.summaryText];
[progressDetailLabel setText:update.detailText];
[progressBar setProgress:[update.percentComplete intValue]];
[progressView setNeedsDisplay];
}
In the init method, you are only assigning the ivars and not retaining them in the new object.
Redo your init method as the following:
-(id) initWithProgressUpdate:(ProgressUpdate *)update {
if ((self = [super init])) {
summaryText = [update.summaryText copy];
detailText = [update.detailText copy];
percentComplete = [[NSNumber alloc] initWithFloat:[update.percentComplete floatValue];
}
return self;
}
Couple of points:
You should not use accessor in the init method
Rename your init method to be a lot clear
In the #property, change the assign to retain
Try removing the statement '[progressUpdateForIssue release];' in the method
'-(void) updateProgressSummary:(NSString *)summary detail:(NSString *)detail percentComplete:(NSNumber *)complete '.
Also change the property attribute from 'assign' to 'retain' in your class ProgressUpdate.
You could release those properties in the dealloc method .
Good luck.
Related
I asked a question yesterday regarding my table view and linking unique detail views to each cell in the table view. I believe I got a good answer to my question here. (Hopefully you can read that post and see what I need). Basically I wanted to know if I am making my singleton correctly. Here is my code:
timerStore.h
#import "Tasks.h"
#interface timerStore : NSObject
{
NSMutableDictionary *allItems;
}
+(timerStore *)sharedStore;
-(NSDictionary *)allItems;
-(NSTimer *)createTimerFor:(Tasks *)t inLocation: (NSIndexPath *)indexPath;
-(void)timerAction;
#end
timerStore.m
#implementation timerStore
+(timerStore *)sharedStore{
static timerStore *sharedStore = nil;
if (!sharedStore)
sharedStore = [[super allocWithZone:nil]init];
return sharedStore;
}
+(id)allocWithZone:(NSZone *)zone{
return [self sharedStore];
}
-(id)init {
self = [super init];
if (self) {
allItems = [[NSMutableDictionary alloc]init];
}
return self;
}
-(NSDictionary *)allItems{
return allItems;
}
-(NSTimer *)createTimerFor:(Tasks *)t inLocation: (NSIndexPath *)indexPath {
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:t.timeInterval target:self selector:#selector(timerAction) userInfo:nil repeats:1.0];
[allItems setObject:timer forKey:indexPath];
return timer;
}
-(void)timerAction{
//custom properties here
}
#end
I'm kind of confused because I was under the impression that a cell's index path gets recycled as you scroll down (dequeue). I may be wrong though. Anyway, am I on the right path to making a singleton as the guy in the link suggested?
The best way to implement App Singleton is as follows
Header file
#import <Foundation/Foundation.h>
#interface AppSingleton : NSObject
#property (nonatomic, retain) NSString *username;
+ (AppSingleton *)sharedInstance;
#end
Implementation File
#import "AppSingleton.h"
#implementation AppSingleton
#synthesize username;
+ (AppSingleton *)sharedInstance {
static AppSingleton *sharedInstance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [[self alloc] init];
});
return sharedInstance;
}
// Initializing
- (id)init {
if (self = [super init]) {
username = [[NSString alloc] init];
}
return self;
}
#end
Note:
What this does is it defines a static variable (but only global to this translation unit) called sharedInstance which is then initialised once and only once in sharedInstance Method. The way we ensure that it’s only created once is by using the dispatch_once method from Grand Central Dispatch (GCD). This is thread safe and handled entirely by the OS for you so that you don’t have to worry about it at all.
Using Singleton To set value
[[AppSingleton sharedInstance] setUsername:#"codebuster"];
Using Singleton to get value.
NSString *username = [[AppSingleton sharedInstance] username];
Further Reference and Reading
I'm diving into iOS programming and I'm learning how to use blocks. I have a sucky, over-engineered library that I'm using in my project and it uses a single callback method to handle all data requests...
#protocol SuckyClassDelegate <NSObject>
-(void)returnedSuckyData:(NSMutableDictionary*)data;
#end
#interface SuckyClass: NSObject
#property (nonatomic, weak) id<SuckyClassDelegate> delegate;
-(void)getSuckyData;
#end
#interface MyViewController: UIViewController <SuckyClassDelegate>
-(void)requestDataFromSuckyClass;
#end
I'd like to create a wrapper class for the SuckyClass that allows me to use blocks when I need to access data from the SuckyClass, but I don't know how to do this. I'd like to have something like this...
#interface SuckyClassWrapper
- (void)requestDataWithSuccessBlock:(void(^)((NSMutableDictionary*)data))successBlock;
#end
#implementation MyViewController
-(void)requestDataFromSuckyClass {
SuckyClassWrapper *wrapper = [[SuckyClassWrapper alloc] init];
[wrapper requestDataWithSuccessBlock:^(NSMutableDictionary *data) {
NSLog(#"%#", data);
}
}
#end
...but I can't figure out how to convert the callback process into blocks. Can anyhow give me some direction here?
Thanks in advance for your wisdom!
By the way, I just whipped up the code without testing it, so I apologize if there are any typos.
The trick is to copy the completion block to a class iVar that you can then call later.
#property (nonatomic, copy) void (^errorHandler)(NSError *);
#property (nonatomic, copy) void (^successHandler)(NSString *);
Here is a method that saves two blocks for use later and then calls another class method:
- (void)methodWithErrorHandler:(void(^)(NSError *error))errorBlock successHandler: (void(^)(NSString *data))successBlock
{
// Copy the blocks to use later
self.successHandler = successBlock;
self.errorHandler = errorBlock;
// Run code
[self doOtherThings];
}
Later - when what we want to do has completed, we have another method that we call to run the blocks. In this silly example code we check to see if a class property self.error is nil. If it is not nil, we send that error to our saved error block. If it is nil, we pass self.data to the success block.
- (void)finishThingsUp
{
// Check to see if we should call the error block or the success block
if (self.error) {
self.errorHandler(self.error);
} else {
self.successHandler(self.data);
}
// Clean up the blocks
self.errorHandler = nil;
self.successHandler = nil;
}
We could use like this:
typedef void (^SuccessDataBlock)(NSMutableDictionary *);
#interface SuckyClassWrapper : NSObject <SuckyClassDelegate>
#property (nonatomic, retain) NSData *inputData;
#property (nonatomic, copy) SuccessDataBlock completionHandler;
+ (id)requestData:(NSData *)data successBlock:(SuccessDataBlock)handler;
#end
#implementation SuckyClassWrapper
#synthesize inputData;
#synthesize completionHandler;
- (id)initWithData:(NSData *)data completionHandler:(SuccessDataBlock)handler
{
self = [super init];
if (self != nil)
{
inputData = [data retain];
self.completionHandler = handler;
}
return self;
}
+ (id)requestData:(NSData *)data successBlock:(SuccessDataBlock)handler
{
return [[[self alloc] initWithData:data completionHandler:handler] autorelease];
}
//implement SuckyClass delegate
- (void)returnedSuckyData:(NSMutableDictionary *)data
{
self.completionHandler(data);
}
#end
Usage:
SuckyClassWrapper *wrapper = [SuckyClassWrapper requestData:data successBlock:^(NSMutableDictionary *successData) {
//your code here
}];
I've reviewed (and tried) a bunch of the threads here regarding Singletons and NSMutableArrays. I'm new to Objective-C so please bear with me.
I simply want to create a few arrays that can be accessed from any view/.m file.
What is the best (or most concise) coding for a Singleton?
Below is what I have now and I get
1 warning at .m '#implementation' - "Incomplete implementation"
1 error at usage in a view .m file - "initializer element is not a compile-time constant"
This is the code I have now - my GlobalData.h file:
#import <Foundation/Foundation.h>
#interface GlobalData : NSObject {
NSMutableArray *listOfHeadings;
NSMutableArray *listOfItems1;
NSMutableArray *listOfItems2;
}
#property(nonatomic,retain)NSMutableArray *listOfHeadings;
#property(nonatomic,retain)NSMutableArray *listOfItems1;
#property(nonatomic,retain)NSMutableArray *listOfItems2;
+(GlobalData*)getInstance;
#end
My GlobalData.m file:
#import "GlobalData.h"
#implementation GlobalData
#synthesize listOfHeadings;
#synthesize listOfItems1;
#synthesize listOfItems2;
static GlobalData *instance=nil;
+(GlobalData *)getInstance
{
#synchronized(self)
{
if(instance==nil)
{
instance= [GlobalData new];
}
}
return instance;
}
#end
And in a view .m file (simplified):
#import GlobalData.h
GlobalData *globDat=[GlobalData getInstance]; //error occurs here
Can someone point out the trouble and if there's better coding, please enlighten me - thanks!
EDIT
Here's a few links I've tried to use:
Can i have a single NSMutableArray in my multiple views application?
iPhone help with singleton class
In this case, you might be doing more than you have to. Granted this certainly isn't always the best solution - but you can put your NSMutableArray as a property in your App Delegate and then easily refer to it from any view. By doing it this way - you aren't locking it in as a 'singleton' but there is a 'singleton instance' of it (this helps a great deal for testability).
I have simplified this process here:
YourAppDelegate.h
#property (nonatomic,retain) NSMutableArray *myArray;
YourAppDelegate.m
#synthesize myArray;
YourViewController.m
YourAppDelegate *appDelegate = (YourAppDelegate *)[[UIApplication sharedApplication] delegate];
NSMutableArray *myArrayFromAppDelegate = appDelegate.myArray;
From this point - you can do any manipulation on this value.
Here's the "modern" version of a single method to turn any class into a Singleton (in this case formatted as a code snippet). It works in iOS4.x or higher:
+(<#SingletonClassName#> *) sharedInstance
{
static <#SingletonClassName#> *_sharedClient = nil;
static dispatch_once_t oncePredicate;
dispatch_once(&oncePredicate, ^{
_sharedClient = [[self alloc] init];
});
return _sharedClient;
}
But, do you really need a singleton of a single NSMutableArray? You could use the built-on singleton - your application delegate, which is got to by calling:
MyAppDelegate * appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate.myMutableArray addObject:...];
The error initializer element is not a compile-time constant is not related to how you create your singleton. The error is how you are accessing your singleton. You are doing this outside of a function:
GlobalData *globDat=[GlobalData getInstance];
This means that you are trying to initialize a global variable (globDat) as the value of the expression [GlobalData getInstance]. You can only initialize global variables to expressions that are "compile-time constants". That means things like 0 or "fred" or 8/2. The value of [GlobalData getInstance] cannot be computed at compile-time, so it cannot be used to initialize the global variable.
Instead, you need to just use [GlobalData getInstance] inside your function bodies wherever you are currently trying to use the globDat variable.
As for the warning, Incomplete implementation, I don't see what's missing. Perhaps you didn't post all of the code from GlobalData.h. Anyway, you should be able to click the warning (where it appears on the right side of the editor window) and have Xcode show you what's missing.
This is the way I create my Singleton:
Singleton.h
#import <Foundation/Foundation.h>
#interface Singleton : NSObject {
NSMutableArray *firstMutableArray;
NSMutableArray *secondMutableArray;
}
#property (nonatomic, retain) NSMutableArray *firstMutableArray;
#property (nonatomic, retain) NSMutableArray *secondMutableArray;
+ (id)sharedSingleton;
#end
Sigleton.m
#import "Singleton.h"
static Singleton *sharedMySingleton = nil;
#implementation Singleton
#synthesize firstMutableArray;
#synthesize secondMutableArray;
#pragma mark Singleton Methods
+ (id)sharedSingleton {
#synchronized(self) {
if (sharedMySingleton == nil) {
sharedMySingleton = [[super allocWithZone:NULL] init];
}
return sharedMySingleton;
}
+ (id)allocWithZone:(NSZone *)zone {
return [[self sharedSingleton] retain];
}
- (id)copyWithZone:(NSZone *)zone {
return self;
}
- (id)retain {
return self;
}
- (unsigned)retainCount {
return UINT_MAX;
}
- (oneway void)release {
// Never release
}
- (id)autorelease {
return self;
}
- (id)init {
if (self = [super init]) {
firstMutableArray = [[NSMutableArray alloc] initWithObjects:nil];
secondMutableArray = [[NSMutableArray alloc] initWithObjects:nil];
}
return self;
}
- (void)dealloc {
[firstMutableArray release];
[secondMutableArray release];
[super dealloc];
}
#end
Then, when you want to call your Singleton:
#import "Singleton.h"
Singleton *singleton = [Singleton sharedSingleton];
singleton.firstMutableArray = ...
singleton.secondMutableArray = ...
I'm making an app that calculates certain things.
I need it to be able to take the input from the first textfields, for example 4+4 and save the result in a variable.
In the second text fields there could be 8+8 for example, and the result of that will also be saved into a variable (possibly the same).
Third row of textfields could yield more numbers etc, etc..
In the end there will be a button "Calculate" for example. And that will take the results from first, second, third etc textfields and calculate all of those together and output the end result.
The calculations are of course more advanced than this, but I just need the basic/simple idea of how to do this.
There is no need for saving the data to a file just now, it should just be in the app while the other textfields are being filled.
For 0x8badf00d:
Header.
#interface UnitConverterViewController : UIViewController {
NSMutableArray *calculationsArray;
UITextField *m1Text;
UITextField *m2Text;
}
#property (nonatomic, retain) IBOutlet UITextField *m1Text;
#property (nonatomic, retain) IBOutlet UITextField *m2Text;
#property (nonatomic, retain) IBOutlet NSMutableArray *calculationsArray;
#end
Implementation:
#implementation UnitConverterViewController
#synthesize m1Text, m2Text, calculationsArray;
#synthesize resultTotal = _resultTotal;
-(id)init {
if(self = [super init]){
calculationsArray = [[NSMutableArray alloc] init];
}
}
- (void)compute{
NSString* sumString = [NSString stringWithFormat:#"%d",[m1Text.text intValue]+[m2Text.text intValue]];
[calculationsArray addObject:sumString];
}
-(IBAction)calculate{
int total=0;
for(NSString* sumStr in calculationsArray){
total = total+[sumStr intValue];
}
NSLog(#"Total: %d", total);
[calculationsArray release], calculationsArray = nil;
}
I must be doing something wrong, and I know I need a way to output this, a label and such. But for now I need to know if what I've done so far is correct, and what the best way of outputting it would be.
You should declare the variables to store the results in your header file, these are than accessible from anywhere in your .m file, the same goes for your text fields.
For example:
Calculator.h
#interface Calculator: SuperclassName{
UITextField *_fldOne;
UITextField *_fldTwo;
UITextField *_fldThree;
UITextField *_fldFour;
int resultOne;
int resultTwo;
int _resultTotal;
}
#property(nonatomic, readonly) int resultTotal;
- (void) calculate;
#end
Calculator.m
#implementation Calculator
#synthesize resultTotal = _resultTotal;
- (void) calculate{
resultOne = [_fldOne.text intValue] * [_fldTwo.text intValue];
resultTwo = [_fldThree.text intValue] / [_fldFour.text intValue];
totalResult = resultOne + resultTwo;
}
#end
In this example resultOne and Two, and all the textfields are available throughout your class to work with, the totalResult is set as a readonly property and synthesized to create a getter automaticaly (which returns the value stored in _totalResult because of synchronizing like totalResult = _totalResult) as so it is available to read from outside the class.
As long as it all happens on one screen it should be more than enough, but of course you could make an NSDictionary or NSArray but that seems unnecessary here.
Hope this helps
Save the result to array. Lets say you have NSMutableArray* calculationsArray;//iVar
//initialize calculationsArray in init method
-(id)init
{
if(self = [super init])
{
calculationsArray = [[NSMutableArray alloc] init];
}
}
- (void)compute
{
NSString* sumString = [NSString stringWithFormat:#"%d",[textField1.text intValue]+[textField2.text intValue]);
[calculationsArray addObject:sumString];
}
- (IBAction)calculate
{
int total=0;
for(NSString* sumStr in calculationsArray)
{
total = total+[sumStr intValue];
}
NSLog(#"Total: %d",total);
[calculationsArray release],calculationsArray = nil;
}
Bear with me on this one.
I have an iphone application. It is a questionnaire application. There are several types of question, some have a slider, some have text input etc. I have developed a view controller for each type of question.
Two example types of question controllers are: TextInputQuestionViewController and SliderQuestionViewController.
I have a rootViewcontroller named QuestionnaireViewController. This is defined as follows:
#import <UIKit/UIKit.h>
#import "JSONKit.h";
#import "dbConnector.h"
#import "SliderQuestionViewController.h";
#import "TextInputQuestionViewController.h";
#import "MainMenuProtocol.h";
#interface QuestionnaireViewController : UIViewController {
NSDictionary* questions;
NSMutableArray* questionArray;
NSMutableArray* answerArray;
dbConnector* db;
SliderQuestionViewController* currQ; //need to create a generic var
TextInputQuestionViewController* currQ;
NSInteger currQNum;
NSString* qaTitle;
NSString* secId;
id<MainMenuProtocol>delegate;
}
#property(nonatomic, retain) NSDictionary* questions;
#property(nonatomic, retain) NSMutableArray* questionArray;
#property(nonatomic, retain) NSMutableArray* answerArray;
#property(nonatomic, retain) dbConnector* db;
#property(nonatomic, retain) SliderQuestionViewController* currQ;
#property(nonatomic, retain) TextInputQuestionViewController* currTI;
#property(nonatomic) NSInteger currQNum;
#property(nonatomic, retain) NSString* qaTitle;
#property(nonatomic, retain) NSString* secId;
#property(nonatomic, retain) id <MainMenuProtocol> delegate;
-(void) setQuestions;
-(void) startQuestion:(NSInteger)index isLast:(BOOL)last;
-(void) loadQuestions;
-(void) initialise;
-(void) finishQuestionnaire:(id)sender;
-(void) switchViews:(id)sender;
#end
#import "QuestionnaireViewController.h"
#import "dbConnector.h"
#import "ASIHTTPRequest.h"
#import "JSONKit.h";
#import "Answer.h";
#implementation QuestionnaireViewController
#synthesize questions, questionArray, db, currQ, currQNum, answerArray, qaTitle, secId, delegate;
-(void)viewDidLoad{
[self initialise];
answerArray = [[NSMutableArray alloc]init];
[super viewDidLoad];
self.title = qaTitle; //set to whatever section is
}
-(void) initialise {
currQNum = 0;
[self loadQuestions];
UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:#"Start" style:UIBarButtonItemStylePlain target:self action:#selector(switchViews:)];
self.navigationItem.rightBarButtonItem = anotherButton;
}
-(void) loadQuestions {
db = [[dbConnector alloc]init];
//code to initialise view
[db getQuestions:secId from:#"http://dev.speechlink.co.uk/David/get_questions.php" respondToDelegate:self];
}
//called when questions finished loading
//stores dictionary of questions
- (void)requestFinished:(ASIHTTPRequest *)request
{
NSData *responseData = [request responseData];
NSString *json = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSDictionary *qs = [json objectFromJSONString];
self.questions = qs;
[json release];
[qs release];
[self setQuestions];
}
//assigns JSON to question objects
-(void) setQuestions {
questionArray = [[NSMutableArray alloc] init];
for (NSDictionary *q in self.questions) {
/* Create Question object and populate it */
id question;
if([[q objectForKey:#"type"] isEqualToString:#"Slider"]){
question = [[SliderQuestionViewController alloc]init];
//set min max values
}else if([[q objectForKey:#"type"] isEqualToString:#"Option"]){
}else if([[q objectForKey:#"type"] isEqualToString:#"TextInput"]){
question = [[TextInputQuestionViewController alloc]init];
}else if([[q objectForKey:#"type"] isEqualToString:#"ImagePicker"]){
}else{
//comments
}
//if else to create appropriate view controller - NEED to identify question type
[question setQuestionId:[q objectForKey:#"questionId"] withTitle:[q objectForKey:#"question"] number:[q objectForKey:#"questionNumber"] section:[q objectForKey:#"sectionId"] questionType: [q objectForKey:#"type"]];
/* Add it to question (mutable) array */
[questionArray addObject:question];
[question release];
}
}
-(void) startQuestion:(NSInteger)index isLast:(BOOL)last{
//currQ = [[QuestionViewController alloc]init];
currQ = [questionArray objectAtIndex:index];
//push currQ onto navigationcontroller stack
[self.navigationController pushViewController:currQ animated:YES];
[currQ addButton:self isLast: last];
}
//pushes new view onto navigation controller stack
-(void) switchViews:(id)sender{
Answer* ans = currQ.question.answer;
ans.questionId = currQ.question.qId;
ans.entryId = #"1";//temporary;
if(currQNum < [questionArray count] - 1){
if(currQNum > 0){
//if else for different input types
NSString* qt = currQ.question.qType;
if([qt isEqualToString:#"Slider"]){
ans.answer = currQ.sliderLabel.text;
}else if([qt isEqualToString:#"Option"]){
}else if([qt isEqualToString:#"TextInput"]){
//NSLog(#"%#", currQ.inputAnswer);
ans.answer = currQ.inputAnswer.text;
}else if([qt isEqualToString:#"ImagePicker"]){
}else{
}
[answerArray addObject: ans];
[ans release];
}
[self startQuestion:currQNum isLast:FALSE];
currQNum++;
}else{
ans.answer = currQ.sliderLabel.text;
[answerArray addObject: ans];
//store data temporarily - section finished
[self startQuestion:currQNum isLast:TRUE];
currQNum++;
}
[ans release];
}
-(void) finishQuestionnaire:(id)sender{
//go back to main manual
//if else statement for answers
NSString* answ = currQ.sliderLabel.text;
[answerArray addObject: answ];
[delegate finishedSection:answerArray section:secId];
[answ release];
[self.navigationController popToRootViewControllerAnimated:YES];
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
self.questions = nil;
self.currQ = nil;
[super viewDidUnload];
}
//hide back button in navigation bar
- (void) viewWillAppear:(BOOL)animated{
self.navigationItem.hidesBackButton = YES;
}
- (void)dealloc {
[currQ release];
[db release];
[questionArray release];
[questions release];
[super dealloc];
}
#end
the problematic lines with the above are in the switchViews function. I need to make the answer equal to the specific input component in that question view (slider value, text input value). So I need to make currQ a type that can be instantiated using any view controller.
I therefore need a generic variable to hold the current question. currQ holds the current question, but at the moment is of type SliderQuestionViewController. I tried to change this to id, but it throws a load of "Request For member...not a structure of union" and also a load of misassigned pointer issues.
Let me know if you need more code.
This reads like you want a pointer for a UIViewController, so just use that as the type. Then you can cast it down to whatever subclass you like later. For example:
-(void)myAction:(UIViewController *)vc {
SpecialViewController *svc = (SpecialViewController *)vc;
...
}
In your case, declare
UIViewController* currQ;
and then cast it as needed in the implementation to access the different properties and methods of your two subclasses.
If you're looking for a 'generic' variable, you should be able to use id. Make sure you don't define the type as id*, the asterisk should not be present.
A better idea, though, is to create a superclass for your question viewcontrollers. Create a superclass called QuestionViewController that inherits from UIViewController and have the Slider and TextInput (and any others) inherit from QuestionViewController. Then you can define your variable as: QuestionViewController* currQ; You can put any common functionality in that superclass as well and eliminate duplication.