Date comparison Iphone - iphone

Question

i have a range of weekly dates like example
1-5-2010 to 7-5-2010
i want the only records which are between two dates how can i compare dates?
and how can i get current week dates.. from current dates...?
thnx in advance..
//alert handler
#import <Foundation/Foundation.h>
#interface AlertHandler : NSObject {
}
+(void)showAlertForProcess;
+(void)hideAlert;
#end
#import "AlertHandler.h"
#implementation AlertHandler
UIAlertView *av;
UIActivityIndicatorView *actInd;
+(void)showAlertForProcess{
if(av!=nil && [av retainCount]>0){ [av release]; av=nil; }
if(actInd!=nil && [actInd retainCount]>0){ [actInd removeFromSuperview];[actInd release]; actInd=nil; }
av=[[UIAlertView alloc] initWithTitle:#"Loading" message:nil delegate:self cancelButtonTitle:nil otherButtonTitles:nil];
actInd=[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
[actInd setFrame:CGRectMake(120, 50, 37, 37)];
[actInd startAnimating];
[av addSubview:actInd];
[av show];
}
+(void)hideAlert{
[av dismissWithClickedButtonIndex:0 animated:YES];
if(av!=nil && [av retainCount]>0){ [av release]; av=nil; }
if(actInd!=nil && [actInd retainCount]>0){ [actInd removeFromSuperview];[actInd release]; actInd=nil; }
}
#end
///Sample of webservice..
-(void)callWebServiceForSignUp{
[AlertHandler showAlertForProcess];
if([gender.text isEqualToString: #"Male"]){
gen=[NSString stringWithFormat:#"1"];
}
else{
gen=[NSString stringWithFormat:#"0"];
}
NSString *soapMsg = [NSString stringWithFormat:#"<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
"<soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">\n"
"<soap:Body>\n"
"<AddUser xmlns=\"http://tempuri.org/\">\n"
"<UserName>%#</UserName>\n"
"<UserEmail>%#</UserEmail>\n"
"<FirstName>%#</FirstName>\n"
"<LastName>%#</LastName>\n"
"<Gender>%#</Gender>\n"
"</AddUser>\n"
"</soap:Body>\n"
"</soap:Envelope>\n",username.text,email.text,firstname.text,lastname.text,gen];
NSURL *myURL=[NSURL URLWithString:[WebService getLoginURL]];
NSMutableURLRequest *connectionReq=[NSMutableURLRequest requestWithURL:myURL];
[connectionReq addValue:#"text/xml; charset=utf-8" forHTTPHeaderField:#"Content-Type"];
[connectionReq addValue:# "http://tempuri.org/AddUser" forHTTPHeaderField:#"SOAPAction"];
[connectionReq setHTTPBody: [soapMsg dataUsingEncoding:NSUTF8StringEncoding]];
[connectionReq addValue:[NSString stringWithFormat:#"%i",[soapMsg length]] forHTTPHeaderField:#"Content-Length"];
[connectionReq setHTTPMethod:#"POST"];
NSURLConnection *myConnection=[[NSURLConnection alloc] initWithRequest:connectionReq delegate:self];
if(myConnection){
myWebData=[[NSMutableData alloc] initWithLength:0];
}else{
UIAlertView *ConnectionNullAlert = [[UIAlertView alloc]initWithFrame:CGRectMake(10, 170, 300, 120)];
ConnectionNullAlert.message=#" can't able to connect to Server!";
ConnectionNullAlert.title=#"Message";
[ConnectionNullAlert addButtonWithTitle:#"OK"];
[ConnectionNullAlert show];
[ConnectionNullAlert release];
}
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
UIAlertView *ConnectionFailAlert = [[UIAlertView alloc]initWithFrame:CGRectMake(10, 170, 300, 120)];
ConnectionFailAlert.message=#" can't able to connect to Server!";
ConnectionFailAlert.title=#"Message";
[ConnectionFailAlert addButtonWithTitle:#"OK"];
[ConnectionFailAlert show];
[ConnectionFailAlert release];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
[myWebData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
[myWebData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSString *str=[[NSString alloc] initWithBytes:[myWebData bytes] length:[myWebData length] encoding:NSStringEncodingConversionAllowLossy];
NSLog(#"%#",str);
[str release];
if(myXMLParser!=nil && [myXMLParser retainCount]>0){ myXMLParser.delegate=nil; [myXMLParser release]; myXMLParser=nil; }
myXMLParser=[[NSXMLParser alloc] initWithData:myWebData];
myXMLParser.delegate=self;
[myXMLParser parse];
[myWebData release];
}
#pragma mark XMLParser methods
-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict{
if([elementName isEqualToString:#"AddUserResult"]){
tempDic=[[NSMutableDictionary alloc] init];
}
}
-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
if(tmpStr!=nil && [tmpStr retainCount]>0){ [tmpStr release]; tmpStr=nil; }
tmpStr=[[NSString alloc] initWithString:string];
}
-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{
if([elementName isEqualToString:#"AddUserResult"] ||
[elementName isEqualToString:#"User_Id"]){
[tempDic setValue:tmpStr forKey:elementName];
NSLog([tempDic description]);
}
}
-(void)parserDidEndDocument:(NSXMLParser *)parser{
[AlertHandler hideAlert];
NSString *errorDesc;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *DataPath = [documentsDirectory stringByAppendingPathComponent:#"Login.plist"];
NSDictionary *plistDict = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects: [tempDic valueForKey:#"User_Id"], nil] forKeys:[NSArray arrayWithObjects:#"userid", nil]];
NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:plistDict format:NSPropertyListXMLFormat_v1_0 errorDescription:&errorDesc];
if (plistData) {
[plistData writeToFile:DataPath atomically:YES];
}
nxthomeview = [[HomeView alloc]initWithNibName:#"HomeView" bundle:nil];
[self.navigationController pushViewController:nxthomeview animated:YES];
[nxthomeview release];
}

Answer 1

Firstly you have to parse 1-5-2010 and 7-5-2010 to NSDate type. You can do it with NSDateFormatter:
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"dd-MM-yyyy"];
NSDate *date1 = [formatter dateFromString:#"1-5-2010"];
NSDate *date2 = [formatter dateFromString:#"7-5-2010"];
//difference between dates in miliseconds
NSTimeInterval interval = [date1 timeIntervalSinceDate:date2];
//interval can be positive or negative, depending on the date1 and date2 values
More about date formatters you get from Apple - Date Formatters
Current date can be got by [NSDate date].
If you want to get the current week, day of the week from date(those are called date components) and so on you can check out the Date and Time Programming Guide