How to pass NSArray from an NSObject class to a UIViewController class? - objective-c

I am new to Objective-C. I am trying to create a weather app where I parsed data from open weather map. I have stored the parsed data to an array. Now want to access the array value from other class but getting null value.
Can anyone help me?
What I have tried:
Here is my NSObject class where I am storing data and trying to send that to view controller:
- (void)getCurrentWeather:(NSString *)query
{
NSString *const BASE_URL_STRING = #"http://api.openweathermap.org/data/2.5/weather?q=";
NSString *const API_KEY = #"&APPID=APIKEYSTRING";
NSString *weatherURLText = [NSString stringWithFormat:#"%#%#%#",
BASE_URL_STRING, query,API_KEY];
NSURL *weatherURL = [NSURL URLWithString:weatherURLText];
dispatch_async(kBgQueue, ^{
NSData* data = [NSData dataWithContentsOfURL:weatherURL];
[self performSelectorOnMainThread:#selector(fetchedDataSmile | :) withObject:data waitUntilDone:YES];
});
}
- (void)fetchedData:(NSData *)responseData {
NSError* error;
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
NSString* cityName = [json objectForKey:#"name"];
int currentTempCelsius = (int)[[[json objectForKey:#"main"] objectForKey:#"temp"] intValue] - ZERO_CELSIUS_IN_KELVIN;
int maxTemp = (int)[[[json objectForKey:#"main"] objectForKey:#"temp_max"] intValue] - ZERO_CELSIUS_IN_KELVIN;
int minTemp = (int)[[[json objectForKey:#"main"] objectForKey:#"temp_min"] intValue] - ZERO_CELSIUS_IN_KELVIN;
NSString *weatherDescription = [[[json objectForKey:#"weather"] objectAtIndexBlush | :O ] objectForKey:#"description"];
weatherArray = [[NSMutableArray alloc] initWithObjects:cityName, weatherDescription,
[NSString stringWithFormat:#"%d", currentTempCelsius],
[NSString stringWithFormat:#"%d", maxTemp],
[NSString stringWithFormat:#"%d", minTemp],nil];
I have NSObject.h file as:
#interface WeatherData : NSObject
#property (nonatomic) NSString *weatherDescription;
#property (strong, nonatomic) NSString *currentTemp;
#property (nonatomic) int maxTempCelsius;
#property (nonatomic) int minTempCelsius;
#property (nonatomic, retain) NSMutableArray *weatherArray;
- (void)getCurrentWeather:(NSString *)query;
#end
In my view controller:
.h file:
#property (nonatomic, retain) NSMutableArray *weatherResultArray;
.m file:
-(void)searchButtonClicked:(UIButton*)sender
{
[self.view endEditing:YES];
WeatherData *weather = [[WeatherData alloc] init];
[weather getCurrentWeather:_textField.text];
self.weatherResultArray = weather.weatherArray;
//temperatureLabel.text = [NSString stringWithFormat:#"%d°",weather.currentTempCelsius];
}
I just want to show the results in UILabel.

Have you tried returning NSMutable array in this method
- (NSMutableArray*)getCurrentWeather:(NSString *)query
instead of this,
- (void)getCurrentWeather:(NSString *)query
This would be the easiest way to verify and also value can be retrieved in single statement as:
self.weatherResultArray = [weather getCurrentWeather:_textField.text];
One more thing, Don't forget to allocate and initialise your weatherResultArray as:
self.weatherResultArray = [[NSMutableArray alloc]init];

In NSObject class, define a weather protocol.
//NSObject.h file
#protocol WeatherDelegate<NSObject>
-(void)getWeatherData:(YourNSObjectClass*)viewController getWeatherData:(NSMutableArray*)array;
#end
//NSObject.m file, in
- (void)fetchedData:(NSData *)responseData {
NSError* error;
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
NSString* cityName = [json objectForKey:#"name"];
int currentTempCelsius = (int)[[[json objectForKey:#"main"] objectForKey:#"temp"] intValue] - ZERO_CELSIUS_IN_KELVIN;
int maxTemp = (int)[[[json objectForKey:#"main"] objectForKey:#"temp_max"] intValue] - ZERO_CELSIUS_IN_KELVIN;
int minTemp = (int)[[[json objectForKey:#"main"] objectForKey:#"temp_min"] intValue] - ZERO_CELSIUS_IN_KELVIN;
NSString *weatherDescription = [[[json objectForKey:#"weather"] objectAtIndexBlush | :O ] objectForKey:#"description"];
weatherArray = [[NSMutableArray alloc] initWithObjects:cityName, weatherDescription,
[NSString stringWithFormat:#"%d", currentTempCelsius],
[NSString stringWithFormat:#"%d", maxTemp],
[NSString stringWithFormat:#"%d", minTemp],nil];
id<WeatherDelegate> strongDelegate = self.delegate;
if ([strongDelegate respondsToSelector:#selector(getWeatherData:getWeatherData:)])
{
[strongDelegate getWeatherData:self getWeatherData:weatherArray];
}
}
In yourViewController class,Add this WeatherData protocol and add the delegate function in .m file to fetch the data.
#interface yourViewControllerClass()<WeatherDelegate>
{
YourNSObjectClass *nsClass;
NSMutableArray *dataArray;
}
-(void)getWeatherData:(YourNSObjectClass*)viewController getWeatherData:(NSMutableArray*)array{
dataArray = [[NSMutableArray alloc]initWithArray:array];
}
-(void)searchButtonClicked:(UIButton*)sender
{
[self.view endEditing:YES];
WeatherData *weather = [[WeatherData alloc] init];
[weather getCurrentWeather:_textField.text];
self.weatherResultArray = dataArray;
//temperatureLabel.text = [NSString stringWithFormat:#"%d°",weather.currentTempCelsius];
}

Related

Converting NSObject to NSDictionary

Hello I a class of type NSObject:
ProductDetails *details = [[ProductDetails alloc] init];
details.name = #"Soap1";
details.color = #"Red";
details.quantity = 4;
I want to pass the "details" object to a dictionary.
I did,
NSDictionary *dict = [NSDictionary dictionaryWithObject:details forKey:#"details"];
I am passing this dict to another method which performs a check on JSONSerialization:
if(![NSJSONSerialization isValidJSONObject:dict])
And I am getting a crash on this check. Am I doing anything wrong here? I know that the details I am getting is a JSON object and I am assigning it to the properties in my ProductDetails class.
Please help me. I am a noob in Objective-C.
I now tried:
NSError* error;
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:(NSData*)details options:kNilOptions error:&error];
All I need here is an easy way to convert details to NSData.
I noticed that I have an array inside my object may be thats why all the ways I tried is throwing an exception. However since this question is becoming to big, I have started an another question thread for it where I have displayed the data I am getting inside the object - https://stackoverflow.com/questions/19081104/convert-nsobject-to-nsdictionary
This may well be the easiest way to achieve it. Do import #import <objc/runtime.h> in your class file.
#import <objc/runtime.h>
ProductDetails *details = [[ProductDetails alloc] init];
details.name = #"Soap1";
details.color = #"Red";
details.quantity = 4;
NSDictionary *dict = [self dictionaryWithPropertiesOfObject: details];
NSLog(#"%#", dict);
//Add this utility method in your class.
- (NSDictionary *) dictionaryWithPropertiesOfObject:(id)obj
{
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
unsigned count;
objc_property_t *properties = class_copyPropertyList([obj class], &count);
for (int i = 0; i < count; i++) {
NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];
[dict setObject:[obj valueForKey:key] forKey:key];
}
free(properties);
return [NSDictionary dictionaryWithDictionary:dict];
}
NSDictionary *details = {#"name":product.name,#"color":product.color,#"quantity":#(product.quantity)};
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:details
options:NSJSONWritingPrettyPrinted // Pass 0 if you don't care about the readability of the generated string
error:&error];
if (! jsonData) {
NSLog(#"Got an error: %#", error);
} else {
NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
}
Second part's source: Generate JSON string from NSDictionary in iOS
As mmackh said, you want to define a custom method for your ProductDetails object that will return a simple NSDictionary of values, e.g.:
#implementation ProductDetails
- (id)jsonObject
{
return #{#"name" : self.name,
#"color" : self.color,
#"quantity" : #(self.quantity)};
}
...
Let's assume that we added manufacturer property to our ProductDetails, which referenced a ManufacturerDetails class. We'd just write a jsonObject for that class, too:
#implementation ManufacturerDetails
- (id)jsonObject
{
return #{#"name" : self.name,
#"address1" : self.address1,
#"address2" : self.address2,
#"city" : self.city,
...
#"phone" : self.phone};
}
...
And then change the jsonObject for ProductDetails to employ that, e.g.:
#implementation ProductDetails
- (id)jsonObject
{
return #{#"name" : self.name,
#"color" : self.color,
#"quantity" : #(self.quantity),
#"manufacturer" : [self.manufacturer jsonObject]};
}
...
If you have potentially nested collection objects (arrays and/or dictionaries) with custom objects that you want to encode, you could write a jsonObject method for each of those, too:
#interface NSDictionary (JsonObject)
- (id)jsonObject;
#end
#implementation NSDictionary (JsonObject)
- (id)jsonObject
{
NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
[self enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
if ([obj respondsToSelector:#selector(jsonObject)])
[dictionary setObject:[obj jsonObject] forKey:key];
else
[dictionary setObject:obj forKey:key];
}];
return [NSDictionary dictionaryWithDictionary:dictionary];
}
#end
#interface NSArray (JsonObject)
- (id)jsonObject;
#end
#implementation NSArray (JsonObject)
- (id)jsonObject
{
NSMutableArray *array = [NSMutableArray array];
[self enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
if ([obj respondsToSelector:#selector(jsonObject)])
[array addObject:[obj jsonObject]];
else
[array addObject:obj];
}];
return [NSArray arrayWithArray:array];
}
#end
If you do something like that, you can now convert arrays or dictionaries of your custom objects object into something that can be used for generating JSON:
NSArray *products = #[[[Product alloc] initWithName:#"Prius" color:#"Green" quantity:3],
[[Product alloc] initWithName:#"Accord" color:#"Black" quantity:1],
[[Product alloc] initWithName:#"Civic" color:#"Blue" quantity:2]];
id productsJsonObject = [products jsonObject];
NSError *error = nil;
NSData *data = [NSJSONSerialization dataWithJSONObject:productsJsonObject options:0 error:&error];
If you're simply trying to save these objects in a file, I'd suggest NSKeyedArchiver and NSKeyedUnarchiver. But if you need to generate JSON objects for your own private classes, you can do something like the above might work.
In .h File
#import <Foundation/Foundation.h>
#interface ContactDetail : NSObject
#property (nonatomic) NSString *firstName;
#property (nonatomic) NSString *lastName;
#property (nonatomic) NSString *fullName;
#property (nonatomic) NSMutableArray *mobileNumbers;
#property (nonatomic) NSMutableArray *Emails;
#property (assign) bool Isopen;
#property (assign) bool IsChecked;
-(NSDictionary *)dictionary;
#end
in .m file
#import "ContactDetail.h"
#import <objc/runtime.h>
#implementation ContactDetail
#synthesize firstName;
#synthesize lastName;
#synthesize fullName;
#synthesize mobileNumbers;
#synthesize Emails;
#synthesize IsChecked,Isopen;
//-(NSDictionary *)dictionary {
// return [NSDictionary dictionaryWithObjectsAndKeys:self.fullName,#"fullname",self.mobileNumbers,#"mobileNumbers",self.Emails,#"emails", nil];
//}
- (NSDictionary *)dictionary {
unsigned int count = 0;
NSMutableDictionary *dictionary = [NSMutableDictionary new];
objc_property_t *properties = class_copyPropertyList([self class], &count);
for (int i = 0; i < count; i++) {
NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];
id value = [self valueForKey:key];
if (value == nil) {
// nothing todo
}
else if ([value isKindOfClass:[NSNumber class]]
|| [value isKindOfClass:[NSString class]]
|| [value isKindOfClass:[NSDictionary class]] || [value isKindOfClass:[NSMutableArray class]]) {
// TODO: extend to other types
[dictionary setObject:value forKey:key];
}
else if ([value isKindOfClass:[NSObject class]]) {
[dictionary setObject:[value dictionary] forKey:key];
}
else {
NSLog(#"Invalid type for %# (%#)", NSStringFromClass([self class]), key);
}
}
free(properties);
return dictionary;
}
#end
if any crash ,You check the property (NSMutableArray,NSString,etc ) in else if condition inside of for.
In Your Controller, in any func...
-(void)addItemViewController:(ConatctViewController *)controller didFinishEnteringItem:(NSMutableArray *)SelectedContact
{
NSLog(#"%#",SelectedContact);
NSMutableArray *myData = [[NSMutableArray alloc] init];
for (ContactDetail *cont in SelectedContact) {
[myData addObject:[cont dictionary]];
}
NSError *error = nil;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:myData options:NSJSONWritingPrettyPrinted error:&error];
if ([jsonData length] > 0 &&
error == nil){
// NSLog(#"Successfully serialized the dictionary into data = %#", jsonData);
NSString *jsonString = [[NSString alloc] initWithData:jsonData
encoding:NSUTF8StringEncoding];
NSLog(#"JSON String = %#", jsonString);
}
else if ([jsonData length] == 0 &&
error == nil){
NSLog(#"No data was returned after serialization.");
}
else if (error != nil){
NSLog(#"An error happened = %#", error);
}
}
Try this:
#import <objc/runtime.h>
+ (NSDictionary *)dictionaryWithPropertiesOfObject:(id)obj {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
unsigned count;
objc_property_t *properties = class_copyPropertyList([obj class], &count);
for (int i = 0; i < count; i++) {
NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];
[dict setObject:[obj valueForKey:key] ? [obj valueForKey:key] : #"" forKey:key];
}
free(properties);
return [NSDictionary dictionaryWithDictionary:dict];
}
The perfect way to do this is by using a library for serialization/deserialization
many libraries are available but one i like is
JagPropertyConverter
https://github.com/jagill/JAGPropertyConverter
it can convert your Custom object into NSDictionary and vice versa
even it support to convert dictionary or array or any custom object within your object (i.e Composition)
JAGPropertyConverter *converter = [[JAGPropertyConverter alloc]init];
converter.classesToConvert = [NSSet setWithObjects:[ProductDetails class], nil];
//For Object to Dictionary
NSDictionary *dictDetail = [converter convertToDictionary:detail];
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:dictDetail options:NSJSONWritingPrettyPrinted error:&error];
You can convert object (say modelObject) to dictionary at runtime with the help of objc/runtime.h class but that has certain limitations and is not recommended.
Considering MVC, mapping logic should be implemented in Model class.
#interface ModelObject : NSObject
#property (nonatomic) NSString *p1;
#property (nonatomic) NSString *p2;
-(NSDictionary *)dictionary;
#end
#import "ModelObject.h"
#implementation ModelObject
-(NSDictionary *)dictionary
{
NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
[dict setValue:self.p1 forKey:#"p1"];// you can give different key name here if you want
[dict setValue:self.p2 forKey:#"p2" ];
return dict;
}
#end
Uses:
NSDictionary *modelObjDict = [modelObj dictionary];
Try using
NSDictionary *dict = [details valuesForAttributes:#[#"name", #"color"]];
And compare what the dictionary contains. Then try to convert it to JSON. And look at the JSON spec - what data types can go into a JSON encoded file?
You also can use the NSObject+APObjectMapping category which is available on GitHub: https://github.com/aperechnev/APObjectMapping
It's a quit easy. Just describe the mapping rules in your class:
#import <Foundation/Foundation.h>
#import "NSObject+APObjectMapping.h"
#interface MyCustomClass : NSObject
#property (nonatomic, strong) NSNumber * someNumber;
#property (nonatomic, strong) NSString * someString;
#end
#implementation MyCustomClass
+ (NSMutableDictionary *)objectMapping {
NSMutableDictionary * mapping = [super objectMapping];
if (mapping) {
NSDictionary * objectMapping = #{ #"someNumber": #"some_number",
#"someString": #"some_string" };
}
return mapping
}
#end
And then you can easily map your object to dictionary:
MyCustomClass * myObj = [[MyCustomClass alloc] init];
myObj.someNumber = #1;
myObj.someString = #"some string";
NSDictionary * myDict = [myObj mapToDictionary];
Also you can parse your object from dictionary:
NSDictionary * myDict = #{ #"some_number": #123,
#"some_string": #"some string" };
MyCustomClass * myObj = [[MyCustomClass alloc] initWithDictionary:myDict];
Swift
Now the swift is very popular and most of the SDK's are written in Objective C, we need to convert NSObject to NSDictionary, With the Help of #thatzprem Answer, I wrote an extension for Swift which will convert our NSObject into NSDictionary, then we can use that NSDictionary to simple Dictionary or JSON Object or other purpose. I hope so this will help out the Swift User.
extension NSObject {
func convertNSObjectToNSDictionary() -> [AnyHashable : Any]? {
var dict: [AnyHashable : Any] = [:]
var count: UInt32 = 0
let properties = class_copyPropertyList(type(of: self), UnsafeMutablePointer<UInt32>(mutating: &count)) //as? objc_property_t
for i in 0..<Int(count) {
var key: String? = nil
if let property = properties?[i] as? objc_property_t {
key = String(utf8String: property_getName(property))
}
//dict[key] = (obj as? NSObject)?.value(forKey: key ?? "")
dict[key] = (self).value(forKey: key ?? "")
}
free(properties)
return dict
}
}

Objective C assigning a dictionary to a variable and accessing it

I'm sorry to ask this question again, but I'm still stuck.
I have a city object trying to fetch weather from a weather fetcher object
#interface WeatherFetcher : NSObject {
}
#property (nonatomic, strong) NSMutableDictionary *weatherData;
- (void)fetchWeather:(NSString *)cityName;
- (void)handleNetworkErorr:(NSError *)error;
- (void)handleNetworkResponse:(NSData *)myData;
#end
This is were I assign the value to weatherData
#import "WeatherFetcher.h"
#implementation WeatherFetcher
- (void)fetchWeather:(NSString *)cityName
{
NSString *urlString = #"http://api.openweathermap.org/data/2.5/weather?q=";
urlString = [urlString stringByAppendingString:cityName];
urlString = [urlString stringByAppendingString:#",Aus"];
NSURL *url = [NSURL URLWithString:urlString];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
if (connectionError)
{
[self handleNetworkErorr:connectionError];
}
else
{
[self handleNetworkResponse:data];
}
}];
}
#pragma mark - Private Failure Methods
- (void)handleNetworkErorr:(NSError *)error
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Network Error" message:#"Please try again later" delegate:nil cancelButtonTitle:nil otherButtonTitles:#"OK", nil];
[alert show];
}
#pragma mark - Private Success Methods
- (void)handleNetworkResponse:(NSData *)myData
{
//NSMutableDictionary *data = [NSMutableDictionary dictionary];
NSMutableDictionary *data = [[NSMutableDictionary alloc] init];
// now we'll parse our data using NSJSONSerialization
id myJSON = [NSJSONSerialization JSONObjectWithData:myData options:NSJSONReadingMutableContainers error:nil];
// typecast an array and list its contents
NSDictionary *jsonArray = (NSDictionary *)myJSON;
//NSLog([jsonArray description]);
// take a look at all elements in the array
for (id element in jsonArray) {
id key = [element description];
id innerArr = [jsonArray objectForKey:key];
NSDictionary *inner = (NSDictionary *)innerArr;
if ([inner conformsToProtocol:#protocol(NSFastEnumeration)]) {
for(id ele in inner) {
if ([ele conformsToProtocol:#protocol(NSFastEnumeration)]) {
NSDictionary *innerInner = (NSDictionary *)ele;
for(id eleEle in innerInner) {
id innerInnerKey = [eleEle description];
[data setObject:[[inner valueForKey:innerInnerKey] description] forKey:[eleEle description]];
}
}
else {
id innerKey = [ele description];
[data setObject:[[inner valueForKey:innerKey] description] forKey:[ele description]];
}
}
}
else {
[data setObject:[inner description] forKey:[element description]];
}
}
self.weatherData = data;
NSLog([self.weatherData description]) **//there is data**
}
#end
However every time I call this from by city object I get nothing back at all.
#import <Foundation/Foundation.h>
#import "WeatherFetcher.h"
#interface City : NSObject {
}
#property (nonatomic, strong) NSString *cityName;
#property (nonatomic, strong) NSString *stateName;
#property (nonatomic, strong) UIImage *cityPicture;
#property (nonatomic, strong) NSString *weather;
#property (nonatomic, strong) NSMutableDictionary *weatherData;
-(NSString *)getWeather;
#end
UI calls getWeather by a button press to get the string value to be displayed on screen
#implementation City {
}
-(NSString *)getWeather {
//return self.weather;
NSString *info = #"";
WeatherFetcher *weatherFetcher = [[WeatherFetcher alloc] init];
[weatherFetcher fetchWeather:self.cityName];
self.weatherData = [weatherFetcher weatherData];
for (id element in self.weatherData) {
info = [info stringByAppendingString:[element description]];
info = [info stringByAppendingString:#"-->"];
info = [info stringByAppendingString:[self.weatherData valueForKey:[element description]]];
info = [info stringByAppendingString:#"\n"];
}
return info;
}
#end
What am I doing wrong here?
getWeather method in the city class gets called when a button is pressed and I'm trying to display this string in a text area. I don't have much experience with Objective C and this is my first app other than Hello World app.
Thank you!
Your WeatherFetcher is asynchronous (sendAsynchronousRequest:) - it sets a task to obtain the data and then returns (usually) before that data has been obtained. So when you try to access the weatherData immediately after the call to fetchWeather: it is not there yet.
You need to redesign your model to handle asynchronicity - getWeather cannot be synchronous. For example you could make fetchWeather: take a completion block to invoke when the data is available and have getWeather pass in a suitable block.

CoreData, transient attribute and EXC_BAD_ACCESS.

I'm trying to build simple file browser and i'm stuck.
I defined classes, build window, add controllers, views.. Everything works but only ONE time.
Selecting again Folder in NSTableView or trying to get data from Folder.files causing silent EXC_BAD_ACCESS (code=13, address0x0) from main.
Info about files i keep outside of CoreData, in simple class, I don't want to save them:
#import <Foundation/Foundation.h>
#interface TPDrawersFileInfo : NSObject
#property (nonatomic, retain) NSString * filename;
#property (nonatomic, retain) NSString * extension;
#property (nonatomic, retain) NSDate * creation;
#property (nonatomic, retain) NSDate * modified;
#property (nonatomic, retain) NSNumber * isFile;
#property (nonatomic, retain) NSNumber * size;
#property (nonatomic, retain) NSNumber * label;
+(TPDrawersFileInfo *) initWithURL: (NSURL *) url;
#end
#implementation TPDrawersFileInfo
+(TPDrawersFileInfo *) initWithURL: (NSURL *) url {
TPDrawersFileInfo * new = [[TPDrawersFileInfo alloc] init];
if (new!=nil) {
NSFileManager * fileManager = [NSFileManager defaultManager];
NSError * error;
NSDictionary * infoDict = [fileManager attributesOfItemAtPath: [url path] error:&error];
id labelValue = nil;
[url getResourceValue:&labelValue forKey:NSURLLabelNumberKey error:&error];
new.label = labelValue;
new.size = [infoDict objectForKey: #"NSFileSize"];
new.modified = [infoDict objectForKey: #"NSFileModificationDate"];
new.creation = [infoDict objectForKey: #"NSFileCreationDate"];
new.isFile = [NSNumber numberWithBool:[[infoDict objectForKey:#"NSFileType"] isEqualToString:#"NSFileTypeRegular"]];
new.extension = [url pathExtension];
new.filename = [[url lastPathComponent] stringByDeletingPathExtension];
}
return new;
}
Next I have class Folder, which is NSManagesObject subclass
// Managed Object class to keep info about folder content
#interface Folder : NSManagedObject {
NSArray * _files;
}
#property (nonatomic, retain) NSArray * files; // Array with TPDrawersFileInfo objects
#property (nonatomic, retain) NSString * url; // url of folder
-(void) reload; //if url changed, load file info again.
#end
#implementation Folder
#synthesize files = _files;
#dynamic url;
-(void)awakeFromInsert {
[self addObserver:self forKeyPath:#"url" options:NSKeyValueObservingOptionNew context:#"url"];
}
-(void)awakeFromFetch {
[self addObserver:self forKeyPath:#"url" options:NSKeyValueObservingOptionNew context:#"url"];
}
-(void)prepareForDeletion {
[self removeObserver:self forKeyPath:#"url"];
}
-(void) observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if (context == #"url") {
[self reload];
}
}
-(void) reload {
NSMutableArray * result = [NSMutableArray array];
NSError * error = nil;
NSFileManager * fileManager = [NSFileManager defaultManager];
NSString * percented = [self.url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSArray * listDir = [fileManager contentsOfDirectoryAtURL: [NSURL URLWithString: percented]
includingPropertiesForKeys: [NSArray arrayWithObject: NSURLCreationDateKey ]
options:NSDirectoryEnumerationSkipsHiddenFiles
error:&error];
if (error!=nil) {NSLog(#"Error <%#> reading <%#> content", error, self.url);}
for (id fileURL in listDir) {
TPDrawersFileInfo * fi = [TPDrawersFileInfo initWithURL:fileURL];
[result addObject: fi];
}
_files = [NSArray arrayWithArray:result];
}
#end
In app delegate i defined
#interface TPAppDelegate : NSObject <NSApplicationDelegate> {
IBOutlet NSArrayController * foldersController;
Folder * currentFolder;
}
- (IBAction)chooseDirectory:(id)sender; // choose folder
and
- (Folder * ) getFolderObjectForPath: path {
//gives Folder object if already exist or nil if not
.....
}
- (IBAction)chooseDirectory:(id)sender {
//Opens panel, asking for url
NSOpenPanel * panel = [NSOpenPanel openPanel];
[panel setCanChooseDirectories:YES];
[panel setCanChooseFiles:NO];
[panel setMessage:#"Choose folder to show:"];
NSURL * currentDirectory;
if ([panel runModal] == NSOKButton)
{
currentDirectory = [[panel URLs] objectAtIndex:0];
}
Folder * folderObject = [self getFolderObjectForPath:[currentDirectory path]];
if (folderObject) {
//if exist:
currentFolder = folderObject;
} else {
// create new one
Folder * newFolder = [NSEntityDescription
insertNewObjectForEntityForName:#"Folder"
inManagedObjectContext:self.managedObjectContext];
[newFolder setValue:[currentDirectory path] forKey:#"url"];
[foldersController addObject:newFolder];
currentFolder = newFolder;
}
[foldersController setSelectedObjects:[NSArray arrayWithObject:currentFolder]];
}
Please help ;)
Ha!
_files = [NSArray arrayWithArray:result];
Should be:
_files = [[NSArray arrayWithArray:result] retain];

Iterate through an NSMutableArray of Objects

I have a class with the following property and method:
header file below - note I did not copy/paste all code (only pertinant information):
#interface SQLiteDB : NSObject
#property (nonatomic, strong) NSMutableArray *allAccountsArray;
#property (nonatomic, strong) NSString *accountId, *accountName, *accountDescription, *accountTags, *accountPhoto, *accountCreationDate;
+(id) populateAccountObjectWithId:(NSString *)id andName:(NSString *)name andDescription:(NSString *)description andTags:(NSString *)tags andPhoto:(NSString *)photo andCreationDate:(NSString *)creationDate;
#end
implementation file below - note I did not copy/paste all code (only pertinant information):
+(id) populateAccountObjectWithId:(NSString *)id andName:(NSString *)name andDescription:(NSString *)description andTags:(NSString *)tags andPhoto:(NSString *)photo andCreationDate:(NSString *)creationDate
{
SQLiteDB *mySQLiteDB = [[self alloc] init];
mySQLiteDB.accountId = id;
mySQLiteDB.accountName = name;
mySQLiteDB.accountDescription = description;
mySQLiteDB.accountTags = tags;
mySQLiteDB.accountPhoto = photo;
mySQLiteDB.accountCreationDate = creationDate;
return mySQLiteDB;
}
Then, another method in the implementation file fetches all accounts from the SQLite database:
-(id) fetchAccountList
{
// do some database stuff here
// create prepared statement, open database, etc...
allAccountsArray = [[NSMutableArray alloc] init];
while(sqlite3_step(statement) == SQLITE_ROW)
{
NSString *thisAccountId = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement,0)];
NSString *thisAccountName = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
NSString *thisAccountDescription = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 2)];
NSString *thisAccountTags = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 3)];
NSString *thisAccountPhoto = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 4)];
NSString *thisAccountCreationDate = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 5)];
[allAccountsArray addObject:[SQLiteDB populateAccountObjectWithId:thisAccountId andName:thisAccountName andDescription:thisAccountDescription andTags:thisAccountTags andPhoto:thisAccountPhoto andCreationDate:thisAccountCreationDate]];
}
// error handling code, etc.
// finalize, & close code here...
return allAccountsArray;
}
Now finally the question. In other classes I want to do stuff with the array of objects that this returns. For instance I would do this in a TableVeiw controller:
-(void)loadView
{
[super loadView];
mySQLiteDB = [[SQLiteDB alloc] init];
allAccountsArray = [mySQLiteDB fetchAccountList];
}
I would use this later to for instance populate the table list in the cellForRowAtIndexPath method. Perhaps each cell of the table would contain the accountName, accountDescription, and accountCreationDate. I do not however know how to access that name, desc, date from within the array of objects...
This obviously produces an error:
cell.textLabel.text = [allAccountsArray objectAtIndex:indexPath.row];
because the object at "row" is an "object" containing name, desc, date, etc...
So Stackoverflow, I ask you... How do I accomplish getting the object variables at each element of the array?
You should be able to do something as simple as this:
SqliteDB *mySqliteDB = (SQliteDB *)[allAccountsArray objectAtIndex:indexPath.row];
NSString *myText = mySqliteDB.thisAccountID;
myText = [myText stringByAppendingString:mySqliteDB.thisAccountName];
.... etc.
cell.textLabel.text = myText;
I think enumerateObjects:usingBlock: is what you want for iterating, i.e. enumerating, objects. You might have missed it because it's in the superclass.

How to implement sort functionality same as AddressBook?

In my app, I have list of contacts which are displayed in ascending order.When user clicks on any alphabet say 'b' then the list should scrolls to the contact starting from 'b'.Is this built-In functionality of AddressBook?Can anyone knows how I can achieve this?
Thanks in advance!
My pretty dirty method. It sorts by email, first name and last name omitting middle name cause I didn't needed that one. Oh and it finds only those contacts which have email address. You can avoid that if you slightly edit code starting with if (ABMultiValueGetCount(emailRef))
Your view controller:
- (NSArray *)sortedContactsFromPeople:(CFArrayRef)people {
NSMutableArray *contacts = [NSMutableArray array];
for (int i = 0; i < CFArrayGetCount(people); i++) {
ABRecordRef record = CFArrayGetValueAtIndex(people, i);
ABMultiValueRef emailRef = ABRecordCopyValue(record, kABPersonEmailProperty);
CFStringRef email;
if (ABMultiValueGetCount(emailRef)) {
BOOL hasValidEmail = NO;
for (int j = 0; j < ABMultiValueGetCount(emailRef); j++) {
if (!hasValidEmail) {
email = ABMultiValueCopyValueAtIndex(emailRef, j);
if ([Validator validateEmail:(NSString *)email] == kValNoErr)
hasValidEmail = YES;
else
CFRelease(email);
}
}
if (hasValidEmail) {
CFStringRef name = ABRecordCopyValue(record, kABPersonFirstNameProperty);
CFStringRef lastname = ABRecordCopyValue(record, kABPersonLastNameProperty);
NSData *contactImageData = (NSData*)ABPersonCopyImageData(record);
UIImage *img = [[[UIImage alloc] initWithData:contactImageData] autorelease];
[contactImageData release];
if (lastname == nil)
lastname = (CFStringRef)#"";
if (name == nil)
name = (CFStringRef)#"";
Contact *contact = [[[Contact alloc] initWithName:(NSString *)name
lastname:(NSString *)lastname
email:(NSString *)email
profileIcon:img] autorelease];
if (![(NSString *)lastname isEqualToString:#""])
contact.sortChar = [(NSString *)lastname substringToIndex:1];
else if (![(NSString *)name isEqualToString:#""])
contact.sortChar = [(NSString *)name substringToIndex:1];
else if (![(NSString *)email isEqualToString:#""])
contact.sortChar = [(NSString *)email substringToIndex:1];
contact.idNumber = ABRecordGetRecordID(record);
[contacts addObject:contact];
if (lastname)
CFRelease(lastname);
if (name)
CFRelease(name);
CFRelease(email);
}
}
CFRelease(emailRef);
}
NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:#"sortChar" ascending:YES selector:#selector(caseInsensitiveCompare:)];
[contacts sortUsingDescriptors:[NSArray arrayWithObject:descriptor]];
return contacts;
}
- (void)initBaseValues {
sections = [[NSMutableDictionary alloc] init];
ABAddressBookRef addressBook = ABAddressBookCreate();
CFArrayRef people = ABAddressBookCopyArrayOfAllPeople(addressBook);
NSInteger section = 0;
NSString *prevChar = nil;
NSArray *contacts = [self sortedContactsFromPeople:people];
for (int i = 0; i < contacts.count; i++) {
Contact *contact = [contacts objectAtIndex:i];
BOOL sectionExists = NO;
if ([prevChar isEqualToString:contact.sortChar])
sectionExists = YES;
if (!sectionExists) {
[sections setObject:[NSMutableArray array] forKey:[NSString stringWithFormat:#"%d", section]];
section++;
}
[prevChar autorelease];
prevChar = [contact.sortChar copy];
[[sections objectForKey:[NSString stringWithFormat:#"%d", section-1]] addObject:contact];
}
if (prevChar != nil)
[prevChar release];
CFRelease(people);
CFRelease(addressBook);
}
Contact.h
#interface Contact : NSObject {
NSString *name;
NSString *lastname;
NSString *email;
UIImage *profileIcon;
NSInteger idNumber;
}
#property (nonatomic, copy) NSString *name;
#property (nonatomic, copy) NSString *lastname;
#property (nonatomic, copy) NSString *email;
#property (nonatomic, retain) UIImage *profileIcon;
#property (nonatomic) NSInteger idNumber;
#property (nonatomic, copy) NSString *sortChar;
- (id)initWithName:(NSString *)name_
lastname:(NSString *)lastname_
email:(NSString *)email_
profileIcon:(UIImage *)profileIcon_;
#end
Doh! I wasn't vigilant enough, to read the whole thing carefully. :) Try creating NSMutableDictionary and each time headerForSection: method is being called store it's offset in the dictionary with appropriate letter as key. Then when user selects "B" letter send your UITableView setContentOffset:animated: method with appropriate offset taken from that dictionary.