Mobile and Social Network Technology

Textfield on cocos2d Mac

2012-12-12T14:14:00.000-08:00

Surprisingly adding a textfield in cocos2d Mac isn't as simple as in cocos2d iOS. There are various suggestions by other coders on how to do this.

This sample code tells you one of the several ways to deal with the textfield in cocos2d Mac.
HERE is the download link.

In this sample code, I have created an external window which opens up when the user hits the textfield.
Here is the UserInterface of nib file. (TextFieldView.xib).

We have following connections on this window.

When I run the app, my window looks like following with textfield which is actually a touch responsive CCMenuItemImage and on top of it sits a CCLabelTTF which says Enter UserName. This string"Enter UserName" will be changed to whatever user enters in the Textfield popup.

When I click on the Enter Username with my mouse, it opens the popup with the textfield. Following code is executed to make the window pop up:

TextfieldProjectAppDelegate* appDelegate = (TextfieldProjectAppDelegate*)[[NSApplication sharedApplication] delegate];

tView = [[TextFieldView alloc] initWithWindowNibName:@"TextFieldView"];

assert ([appDelegate window]);

assert ([tView window]);

[NSApp beginSheet:[tView window]

modalForWindow:[appDelegate window]

modalDelegate:self

didEndSelector:@selector(usernameSheetDidEnd:returnCode:contextInfo:)

contextInfo:NULL];

We also need to define a selector which is where the control comes back when the popup is gone, hence we implement the following:

- (void)usernameSheetDidEnd:(NSWindow *)sheet returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo {

[sheet orderOut:nil];

NSLog(@"name == %@", tView.username);

//Need to update text on textfield

CCLabelTTF *userName=(CCLabelTTF*)[self getChildByTag:106];

userName.string=tView.username;

}

When you are done entering the value in textfield popup, just hit the OK button. When you do that following method(implemented in TextFieldView.m ) is executed. This method makes the popup go away. This is the selector method attached with OK button. You can view the connections in the Xib Interface Window in Xcode (already described above).

- (IBAction)usernameEntered:(id)sender {

username=[nameField stringValue];

[NSApp endSheet:self.window];

}

Conversion between CGPoint & NSValue (Mac)

2012-11-22T11:32:00.000-08:00

To convert CGPoint to NSValue:

NSValue valueXY = [NSValue valueWithPoint:CGPointMake(X, Y)];

To retrieve CGPoint from NSValue:

CGPoint mPoint=[valueXY pointValue];

Icons for Mac App

2012-11-22T09:30:00.001-08:00

This article also covers how to create .icns file which is used as icon for Mac Applications.

First,you need to create a folder with .iconset as suffix.
This folder will have following items with the dimensions mentioned and named as per screenshot.

icon_16x16.png
icon_16x16@2x.png
icon_32x32.png
icon_32x32@2x.png
icon_128x128.png
icon_128x128@2x.png
icon_256x256.png
icon_256x256@2x.png
icon_512x512.png
icon_512x512@2x.png

You go into the directory where you saved icon.iconset folder and then run following command on Terminal to create icns file.

> iconutil -c icns icon.iconset/

This will give you a single file as output named icon.icns in the same parent directory as icon.iconset, Add this file to resources of your application. Now in your project, you need to update the Icon name in Info.plist like in screenshot here.

Note: Apple documents say that you can add icon.iconset folder itself to your app's resources and Xcode 4.4 automatically creates .icns file for you. It also notes that "Don’t use Icon Composer—it can’t create high-resolution icns files." . HERE IS THE LINK

Cocos2d For Mac

2012-11-20T08:14:00.002-08:00

Create a folder say(Cocos2DGame) where you want to download a copy of Cocos2d:

On your Terminal,
> git clone git://github.com/cocos2d/cocos2d-iphone.git

After this command a copy of Cocos2d will exist in Cocos2DGame folder. You need to step into Cocos2DGame folder by doing 

>cd Cocos2DGame

>git checkout develop

You need to install the cocos2d Mac Template in XCode

>sudo ./install-templates.sh

Now when you start a new project in Xcode, you will see the installed Cocos2d for Mac .

Note: You need to install git on your Mac Machine before you can run those git commands given above.

Download and Install dmg
http://code.google.com/p/git-osx-installer/downloads/list

How to use NSScanner on NSString.

2012-08-14T19:55:00.001-07:00

This is quiet useful in terms of parsing a simple static webpage, also pick certain kind of words from the NSString.

Lets say we have following snippet from a html file.

NSString *htmlString=

< div id="topLeft" class="news" style="padding-top:3px"

onMouseOver="style.color='white';style.backgroundColor='#F0ABFF'" onMouseOut="style.color='black';style.backgroundColor='#000000'"><a style="text-decoration:none;color:black" onMouseOver="style.color='white'" onMouseOut="style.color='black'"href="reetu/test/news.htm" target="_blank">Latest News</a>

Now I want to extract the url, text and div id from this html file snippet. Following code will give you that.

NSScanner *rScanner = [NSScanner scannerWithString:string];
NSString *divID=@"";

[rScanner scanString:@"<div id=\"" intoString:NULL];

[rScanner scanUpToString:@"class=\"news\"" intoString:&courseID];

divID=[divID stringByReplacingOccurrencesOfString:@" " withString:@""];

divID=[divID stringByReplacingOccurrencesOfString:@"\"" withString:@""];

divID=[divID stringByReplacingOccurrencesOfString:@"<divid=" withString:@""];
NSLog(@"divID=%@",divID);

/*Instead of above 3 lines you could also do [rScanner scanUpToString: instead of scanString:

NSString *rURL=@"";
[rScanner scanUpToString:@"href=\"" intoString:NULL];
[rScanner scanUpToString:@">" intoString:&rURL];
rURL=[rURL stringByReplacingOccurrencesOfString:@"href=\"" withString:@""];
rURL=[rURL stringByReplacingOccurrencesOfString:@"target=\"_blank\"" withString:@""];
rURL=[rURL stringByReplacingOccurrencesOfString:@"\" " withString:@""];
NSLog(@"rURL=%@",rURL);

NSString *rName=@"";

[rScanner scanUpToString:@"</a>" intoString:&rName];

rName=[courseName stringByReplacingOccurrencesOfString:@">" withString:@""];

NSLog(@"rName=%@",rName);

It will print following results:

divID=topLeft

rURL=reetu/test/news.htm

rName=Latest News

Tips: How to find if NSDictionary has a key.

2012-08-01T11:50:00.002-07:00

if ([[myDiction allKeys] containsObject:@"myKey"])

NSLog(@"It contains myKey");

How to use NSAttributedString in iOS 6

2012-07-31T22:38:00.001-07:00

infoString=@"This is an example of Attributed String";

NSMutableAttributedString *attString=[[NSMutableAttributedString alloc] initWithString:infoString];

NSInteger _stringLength=[infoString length];

UIColor *_black=[UIColor blackColor];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:30.0f];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSForegroundColorAttributeName value:_black range:NSMakeRange(0, _stringLength)];

UIColor *_red=[UIColor redColor];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:72.0f];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSStrokeColorAttributeName value:_red range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSStrokeWidthAttributeName value:[NSNumber numberWithFloat:3.0] range:NSMakeRange(0, _stringLength)];

UIColor *_red=[UIColor redColor];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:72.0f];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSStrokeColorAttributeName value:_red range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSStrokeWidthAttributeName value:[NSNumber numberWithFloat:-3.0] range:NSMakeRange(0, _stringLength)];

UIColor *_red=[UIColor redColor];

UIColor *_green=[UIColor greenColor];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:72.0f];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSForegroundColorAttributeName value:_green range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSStrokeColorAttributeName value:_red range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSStrokeWidthAttributeName value:[NSNumber numberWithFloat:-3.0] range:NSMakeRange(0, _stringLength)];

UIColor *_green=[UIColor greenColor];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:72.0f];

NSShadow *shadowDic=[[NSShadow alloc] init];

[shadowDic setShadowBlurRadius:5.0];

[shadowDic setShadowColor:[UIColor grayColor]];

[shadowDic setShadowOffset:CGSizeMake(0, 3)];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSForegroundColorAttributeName value:_green range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSShadowAttributeName value:shadowDic range:NSMakeRange(0, _stringLength)];

UIColor *_red=[UIColor redColor];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:72.0f];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSForegroundColorAttributeName value:_red range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSKernAttributeName value:[NSNumber numberWithInt:5] range:NSMak

UIColor *_red=[UIColor redColor];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:30.0f];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSForegroundColorAttributeName value:_red range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:2] range:NSMakeRange(0, _stringLength)];

UIColor *_blue=[UIColor blueColor];

UIColor *_blueL=[UIColor colorWithRed:0 green:0 blue:0.5 alpha:0.7];

UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:30.0f];

[attString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSForegroundColorAttributeName value:_blue range:NSMakeRange(0, _stringLength)];

[attString addAttribute:NSBackgroundColorAttributeName value:_blueL range:NSMakeRange(0, 20)];

Tips: Hide scrollbars of UIScrollView

2012-07-26T21:36:00.003-07:00

[mScrollView setShowsHorizontalScrollIndicator:NO];

[mScrollView setShowsVerticalScrollIndicator:NO];

How to animate a line draw ?

2012-07-24T20:44:00.002-07:00

If you want to draw a line pixel by pixel.
You will have to use combination of UIBezierPath, CAShapeLayer, CABasicAnimation. You can download the code here. The piece of code given below animates a simple line drawn pixel by pixel from point (50.0,0.0) to point (120.0, 600.0).

UIBezierPath *path = [UIBezierPath bezierPath];

[path moveToPoint:CGPointMake(50.0,0.0)];

[path addLineToPoint:CGPointMake(120.0, 600.0)];

CAShapeLayer *pathLayer = [CAShapeLayer layer];

pathLayer.frame = self.view.bounds;

pathLayer.path = path.CGPath;

pathLayer.strokeColor = [[UIColor redColor] CGColor];

pathLayer.fillColor = nil;

pathLayer.lineWidth = 2.0f;

pathLayer.lineJoin = kCALineJoinBevel;

[self.view.layer addSublayer:pathLayer];

CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];

pathAnimation.duration = 2.0;

pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];

pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];

[pathLayer addAnimation:pathAnimation forKey:@"strokeEnd"];

convert NSArray in float[]

2012-07-21T23:30:00.001-07:00

NSArray *c=[NSArray arrayWithObjects:@"1",@"8",@"4",@"2",nil];

NSEnumerator *enumerator;

float * cArray;

id obj;

int index=0;

cArray = (float *) malloc(sizeof(float) * [c count]);

enumerator = [c objectEnumerator];

while(obj = [enumerator nextObject])

{

cArray[index] = [obj floatValue];

index++;

}

Ad Hoc Build in XCode 4.3+ and XCode 4.5

2012-07-19T16:56:00.003-07:00

Things have changed a little bit for ad hoc. This post is for people who may face problem while trying to create adhoc. While trying to install .ipa on device through iTunes, it gives error "iTunes sync failed to start"

Make sure your mobile provisioning for ad-hoc and distribution certificate is installed before we proceed any further. You can go through my old post, it is very detailed, just to refresh things like how to create certificate and other required things.

Note: You can read captions on the image for more clarity.


Add Ad Hoc configuration by duplicating release (You can do that by pressing + sign)	)

You need to add distribution signing profile for Ad Hoc as well as Release.

Now on top left corner of your XCode screen. Click on project Name like here I click on MIMChartLIb

I get popup like this.Click on Edit Scheme.

Go to Archieve(Highlighted cell on left tableview). On right side,Change Build Configuration to Ad Hoc.Click OK.

Now go to Product > Archive

It will ask you to sign with keys. Click Allow or Always Allow.

After sometime, Organiser window will open displaying Archive. If not, You can open Organiser from Xcode Menu: Window>Organiser.

Clicking on Distribute button on previous screen, opens this. Choose second option here.

Next it asks for Code Signing Identity, Choose your Ad-Hoc distribution profile.

It will ask you to sign with the key Click Allow or Always Allow.

After sometime, it will ask you where to save your .ipa file. Thats it ! You select your location and click Save.

Tutorial: How to use QLPreviewController to preview files.

2012-07-17T15:11:00.003-07:00

This tutorial will talk about implementation of preview feature of documents, images and files available on iOS 4.0 onwards. Apple reference document says:

A Quick Look preview controller can display previews for the following items:

iWork documents
Microsoft Office documents (Office ‘97 and newer)
Rich Text Format (RTF) documents
PDF files
Images
Text files whose uniform type identifier (UTI) conforms to the public.text type (see Uniform Type Identifiers Reference)
Comma-separated value (csv) files

You need to add QuickLook.framework in your project. and import QuickLook/QuickLook.h
and add protocols <QLPreviewControllerDataSource,QLPreviewControllerDelegate>

QLPreviewController *previewController=[[QLPreviewController alloc]init];

previewController.delegate=self;

previewController.dataSource=self;

[self presentModalViewController:previewController animated:YES];

[previewController.navigationItem setRightBarButtonItem:nil];

You need to add datasource methods for sure. Return more than 1 for numberOfPreviewItemsInPreviewController if you want user to be able to preview next and previous file while in preview mode. Else return 1 if you want user to exclusively preview only selected file.

- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller

- (id <QLPreviewItem>)previewController:(QLPreviewController *)controller previewItemAtIndex:(NSInteger)index

You may add delegate methods optionally depending on your requirements. In Sample code, I have used these delegate methods to add the zooming effect where the preview seems to come out of the same button clicked by user.

- (BOOL)previewController:(QLPreviewController *)controller shouldOpenURL:(NSURL *)url forPreviewItem:(id <QLPreviewItem>)item

- (CGRect)previewController:(QLPreviewController *)controller frameForPreviewItem:(id <QLPreviewItem>)item inSourceView:(UIView **)view

For more information, you can view the Apple reference document.

Link of the sample code to download.

Make a difference with your App.

2012-07-17T10:23:00.000-07:00

This is a great video inspiring the developers to make an app which actually makes a difference ! LINK

Importance of SLComposeViewControllerCompletionHandler

2012-07-16T17:34:00.003-07:00

You need to add the handler(SLComposeViewControllerCompletionHandler) otherwise you may get following error when you try to cancel the Facebook Post or post the Post:

viewServiceDidTerminateWithError:: Error Domain=_UIViewServiceErrorDomain Code =1 "The operation couldn't be completed. (_UIViewServiceErrorDomain error 1.)"

You need to create handler like following

SLComposeViewControllerCompletionHandler __block completionHandler=^(SLComposeViewControllerResult result)

{

[fbController dismissViewControllerAnimated:YES completion:nil];

switch(result){

case SLComposeViewControllerResultCancelled:

default:

{

NSLog(@"Cancelled.....");

}

break;

case SLComposeViewControllerResultDone:

{

NSLog(@"Posted....");

}

break;

}};

and add this handler to SLComposeViewController

SLComposeViewController *fbController=[SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];

[fbController setCompletionHandler:completionHandler];

and you can see the last post to see how to use it completely with the sample code. LINK.

Tutorial: How to use inbuilt Facebook/Twitter API in iOS6.

2012-07-16T17:24:00.003-07:00

You need to add Social.framework in your project.
Add to your file following #import "Social/Social.h"

You can create 3 type of service:

SLServiceTypeTwitter;

SLServiceTypeFacebook;

SLServiceTypeSinaWeibo;

I have created service of Facebook.

SLComposeViewController *fbController=[SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];

if([SLComposeViewController isAvailableForServiceType:SLServiceTypeFacebook])

{

SLComposeViewControllerCompletionHandler __block completionHandler=^(SLComposeViewControllerResult result){

[fbController dismissViewControllerAnimated:YES completion:nil];

switch(result){

case SLComposeViewControllerResultCancelled:

default:

{

NSLog(@"Cancelled.....");

}

break;

case SLComposeViewControllerResultDone:

{

NSLog(@"Posted....");

}

break;

}};

[fbController addImage:[UIImage imageNamed:@"1.jpg"]];

[fbController setInitialText:@"Check out this article."];

[fbController addURL:[NSURL URLWithString:@"http://soulwithmobiletechnology.blogspot.com/"]];

[fbController setCompletionHandler:completionHandler];

[self presentViewController:fbController animated:YES completion:nil];

}

I have added image which will be posted with the message and URL on the Facebook page. Here is what the message looks like on FB.

Following are some screenshots of the app running.

If the Facebook account is not set up on device, it gives you this pop up.

SLComposeViewController with added URL and Image.

SLComposeViewController with added text,URL and image,
Also location has been set on the post
just like we can do on our Facebook page.

You can change the album in which you want to post this image.

You can choose which group you want to display this post to.

Link to download the sample code.

Mac OS Evolution

2012-07-12T09:34:00.002-07:00

1978 Apple introduces Apple DOS 3.1, the first operating system for the Apple computers in June.

1984 Apple introduces System 1.

1985 Apple introduces System 2.

1986 Apple introduces System 3.

1987 Apple introduces System 4.

1988 Apple introduces System 6.

1991 Apple introduces System 7 operating system May 13, 1991.

1995 Apple allows other computer companies to clone its computer by announcing its licensed the Macintosh operating system rights to Radius on January 4.

1997 Apple introduces Mac OS 8. 1997Apple buys NeXT Software Inc. for $400 million and acquires Steve Jobs, Apples cofounder, as a consultant.

1999 Apple introduces Mac OS 9.

2001 Apple introduces Mac OS X 10.0 named Cheetah and becomes available March 24, 2001.

2001 Apple introduces Mac OS X 10.1 named Puma and becomes available on September 25, 2001.

2002 Apple introduces Mac OS X 10.2 named Jaguar and becomes available on August 23, 2002.

2003 Apple introduces Mac OS X 10.3 named Panther October 25, 2003.

2004 Apple introduces Mac OS X 10.4 named Tiger at the WWDC on June 28, 2004.

2007 Apple introduces Mac OS X 10.5 named Leopard October 26, 2007.

2008 Apple introduces Mac OS X 10.6 named Snow Leopard and MobileMe at the WWDC on June 9, 2008.

2011 Apple introduces Mac OS X 10.7 named Lion was released on July 20, 2011.

2012 Apple introduces Mac OS X 10.8 named Mountain Lion will be released in July 2012.

Features in new Mountain Lion OS.

2012-07-10T21:14:00.005-07:00

Atmosphere is again hot with the anticipation of new Mac OS. Again, millions of 20 dollars will be added to trillion dollar Apple :) Lets take a quick look at the feature list.

iCloud is automatic and effortless now. Just sign in once with your Apple ID and iCloud is set up in all the apps that use it.

Reminder: Set due dates and you’ll get alerts as deadlines approach. Set a location from your Mac, and your iPhone or iPad will remind you when you get there.

Notes: Its more noteworthy with photos, images, and attachments.Pin important notes to your desktop so they’re easy to get to.

iMessage: You can send messages to anyone on an iPhone, iPad, or iPod touch running iOS 5, too.Send photos, videos, documents, and contacts — even send messages to a group.

Notification Center just like iPad—for any new email, a message, a software update or a calendar alert.

Power Nap is most awesome-It periodically updates Mail, Contacts, Calendar, Reminders, Notes, Photo Stream, Find My Mac, and Documents in the Cloud,downloads software updates and makes backups with Time Machine. While updating, the system sounds are silent and no lights or fans come on, so nothing disturbs you as reported on Apple's website.

Dictation -It converts your words into text.And it recognizes people from your contacts so it enters names accurately. Dictation supports English (U.S., UK, and Australia), French, German, and Japanese.

Share Button-There is Share button throughout OS X Mountain Lion.

Built-in Facebook support- You can share what’s up with you right from the app you’re in. Post photos or links. Add comments and locations.OS X adds your Facebook friends and their profile photos to Contacts.

Built-in Twitter support- OS X Mountain Lion is designed for tweeting. Sign in once and you’re all set up .You can tweet from Notification Center, too.

Game Center app - You can play anyone on a Mac, iPad, iPhone, and iPod touch.Just use your Game Center account from iOS or create one with your Apple ID. Then sign in and you’re in.

Gatekeeper -It helps protect you from downloading and installing malicious software on your Mac.

Safari- When you open web pages on your iPhone or iPad, iCloud Tabs makes them available on your Mac, too. So you can pick up browsing wherever you left off. Safari saves entire web pages in your Reading List,not just the links.

To read full list of 200+ features, HERE is the link.

Running on iPhone or iPad ?

2012-07-10T18:42:00.003-07:00

Developing a universal app makes it a necessity to find out if the app is running on iPhone or iPad, accordingly you write your code block.
Here is the code:

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)

{

}

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)

{

}

How to find OS version of iOS device.

2012-07-10T18:35:00.002-07:00

NSString *currentOS = [[UIDevice currentDevice] systemVersion];

How to check if current OS is minimum version you need. Suppose minimum you need is 4.2

NSString *currentOS = [[UIDevice currentDevice] systemVersion];

if ([currentOS compare:@"4.2" options:NSNumericSearch] != NSOrderedAscending)

{

NSLog(@"Yes, it is greater than or equal to 4.2");

}

How to add Event in device Calender.

2012-07-02T08:02:00.005-07:00

EKEventStore *eventStore = [[EKEventStore alloc] init];

EKEvent *event = [EKEvent eventWithEventStore:eventStore];

event.title = @"My Event Name";

event.startDate =[NSDate date];

event.endDate = [[NSDate alloc] initWithTimeInterval:60 sinceDate:event.startDate];

[event setCalendar:[eventStore defaultCalendarForNewEvents]];

NSError *err;

[eventStore saveEvent:event span:EKSpanThisEvent error:&err];

And don't forget to add #import to your file and EventKit framework to your project.

Save NSDate in CoreData

2012-06-28T20:58:00.002-07:00

1. In your model file.
Create an entity MyDate with attribute datestring of datatype date(select it from dropdown).

2. Save your date

//Create date from the string

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:@"dd-MM-yyyy"];

NSDate *date=[dateFormatter dateFromString:dateString_];

[dateFormatter release];

dateFormatter=nil;

//Save the auditDate Now

MyDate *obj = [NSEntityDescription insertNewObjectForEntityForName:@"MyDate" inManagedObjectContext:context];

[obj setValue:date forKey:@"datestring"];

NSError* error = nil;

[context save:&error];

if (error)

{

NSLog(@"%@", error);

}

3. Retrieve your date

When you retrieve MyDate objects, accessing value of key datestring will return NSDate, you can convert that to NSString to display it on your screen.

Get number of days in a month

2012-06-28T08:09:00.000-07:00

NSDate *today=[NSDate date];

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

NSRange days = [gregorian rangeOfUnit:NSDayCalendarUnit inUnit:NSMonthCalendarUnit forDate:date];

int daysInGivenMonth= days.length;

Get first day of a month.

2012-06-28T08:02:00.001-07:00

First we will build first date (01-xx-xxxx)of a given month.
Of course you can change 01 to anything like 12,26 or whatever date you want to find day of.

int month = 4;

int year=2012;

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:@"dd-MM-yyyy"];

NSDate *date=[dateFormatter dateFromString:[NSString stringWithFormat:@"01-%i-%i",month,year]];

[dateFormatter release];

dateFormatter=nil;

Then we will find day for the above date in Gregorian Calendar. You can choose the method give in previous article where you create NSDateFormatter with @"EEEE",But if you are calendar specific, then following is the way.

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

NSDateComponents *weekdayComponents =[gregorian components:NSWeekdayCalendarUnit fromDate:date];

int firstDay = [weekdayComponents weekday];//1 for Sun,2 for Mon etc

[gregorian release];

Get Day Name in NSDate

2012-06-28T07:54:00.001-07:00

In this example we will find what day(Sun, Mon or Tue etc) is it for a given date.

NSDate *today=[NSDate date];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:@"EEEE"];

NSString *currentDay = [dateFormatter stringFromDate:today];

NSLog(@"currentDay=%@", currentDay);

//currentDay is 1 for Sun, 2 for Mon

[dateFormatter release];

Get Month from NSDate

2012-06-28T07:51:00.002-07:00

In this example we will take todays date and find the month in todays date.

NSDate *today=[NSDate date];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];

[dateFormatter setDateFormat:@"M"];

NSString *currentMonth = [dateFormatter stringFromDate:today];

//currentMonth will be 1 for Jan, 2 for Feb etc

NSLog(@"currentMonth=%@",currentMonth);

[dateFormatter release];