I am working on a Cocoa Mac OSX app, and I am wondering if it is possible to present the contents of an NSRange found by:
NSRange range;
range.location = 4;
range.length = 4;
as an NSString?
e.g. in the example above, if I had a string with contents "abcdefgh", presenting the contents of the above range as a string would give "efgh". Is this possible?
Code:
NSString *string = #"abcdefgh";
NSRange range;
range.location = 4;
range.length = 4;
NSString *subString = [string substringWithRange:range];
NSLog(#"%#",subString);
Output:
efgh
Try the method substringWithRange from NSString.
NSString* original = #"abcdefgh";
NSLog(#"Substring: %#", [original substringWithRange:range]);
Related
How can I extract numbers from a string defined like:
NSString *getNumber = #"Price138.50 Code112.250"
I need to extract both 138.50 and 112.25 from this string.
Use NSScanner, slightly modified from this Apple example:
NSCharacterSet *numberCharset = [NSCharacterSet characterSetWithCharactersInString:#"0123456789-"];
NSScanner *theScanner = [NSScanner scannerWithString:aString];
while (![theScanner isAtEnd]) {
// Eat non-digits and negative sign
[theScanner scanUpToCharactersFromSet:numberCharset
intoString:NULL];
float aFloat;
if ([theScanner scanFloat:&aFloat]) {
NSLog(#"Found %f", aFloat);
}
}
NSString *getNumber = #"Price138.50 Code112.250";
getNumber = [getNumber stringByReplacingOccurrencesOfString:#"Price" withString:#""];
getNumber = [getNumber stringByReplacingOccurrencesOfString:#"Code" withString:#""];
getNumber = [getNumber stringByReplacingOccurrencesOfString:#" " withString:#","];
NSArray *values = [getNumber componentsSeparatedByString:#","];
NSLog(#"Price Value: %#", [values firstObject]);
NSLog(#"Code Value: %#", [values lastObject]);
If your string will be of same kind then this can be a possible way. Not Recommended.
I'm currently pulling info from an sql DB where the 'cachedDist' column is set as a double. However when I pull it into my app and create my array I turn it into an String and the sort will obviously be off, 18.15 will come before 2.15. How do I fix that in my code so it will sort distance as a Double and not a String?
In Bar object.
NSString *cachedDist
#property(nonatomic,copy) NSString *cachedDist;
#synthesize cachedDist;
My while loop in the View Controller.
while (sqlite3_step(sqlStatement)==SQLITE_ROW) {
Bar * bar = [[Bar alloc] init];
bar.barName = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,1)];
bar.barAddress = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,2)];
bar.barCity = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 3)];
bar.barState = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 4)];
bar.barZip = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 5)];
bar.barLat = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 8)];
bar.barLong = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 9)];
if (currentLoc == nil) {
NSLog(#"current location is nil %#", currentLoc);
}else{
CLLocation *barLocation = [[CLLocation alloc] initWithLatitude:[bar.barLat doubleValue] longitude:[bar.barLong doubleValue]];
bar.cachedDist = [NSNumber numberWithDouble:[currentLoc distanceFromLocation: barLocation]/1000];
[thebars addObject:bar];
}
My sorting
NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:#"cachedDist" ascending:YES];
sortedArray = [thebars sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]];
return sortedArray;
NSString has a method doubleValue to make this quite simple:
double cachedDistance = [cachedDistanceString doubleValue];
which you can use in a custom comparator for your sorting, or else make the property an NSNumber or double to make sorting that much easier. (I'm not sure how you are sorting...)
edit:
I re-evaluated your code, and now it looks like we are going from a double to a string to a double... we can cut out the middle-man, so to speak.
In your #prototype section, change the #property:
// #property(nonatomic,copy) NSString *cachedDist; // old way
#property(nonatomic) double cachedDist;
then assign it like this:
bar.cachedDistance = [currentLoc distanceFromLocation: barLocation]/1000;
and remove the lines which create a string from the distance (which is actually just a double).
Alternatively, if you want to be more object oriented, you can (should?) use NSNumber objects:
#property(nonatomic,copy) NSNumber *cachedDist;
...
bar.cachedDistance = [NSNumber numberWithDouble:[currentLoc distanceFromLocation: barLocation]/1000];
NOTE: I'm developing for Mac, not iOS!
- (void)recordTransaction:(SKPaymentTransaction *)transaction
{
if ([transaction.payment.productIdentifier isEqualToString:kInAppProIdentifier])
{
[[NSUserDefaults standardUserDefaults] setValue:transaction.transactionReceipt forKey:#"proUpgradeTransactionReceipt" ];
[[NSUserDefaults standardUserDefaults] synchronize];
}
}
I get this error from the compiler:
error: property 'transactionReceipt' not found on object of type 'SKPaymentTransaction *'; did you mean 'transactionDate'? [3]
Also, I can't find the transactionReceipt property in the reference for the SKPaymentTransaction class! (Even though this page contains some references to "receipts", there's not a transactionReceipt property).
But the documentation says it is supposed to exist!
A successful transaction includes a transactionIdentifier property and a transactionReceipt property that record the details of the processed payment. Your application is not required to do anything with this information. You may wish to record this information to establish an audit trail for the transaction. If your application uses a server to deliver content, the receipt can be sent to your server and validated by the App Store.
What is wrong with this?
The property is private and returns an empty string on OS X.
As stated in Apple's docs here:
https://developer.apple.com/library/mac/documentation/NetworkingInternet/Conceptual/StoreKitGuide/VerifyingStoreReceipts/VerifyingStoreReceipts.html#//apple_ref/doc/uid/TP40008267-CH104-SW1
"On iOS, this is the value of the transaction's transactionReceipt
property. On OS X, this is the entire contents of the receipt file
inside the application bundle. Encode the receipt data using base64
encoding."
To get the receipt, use:
[NSData dataWithContentsOfURL:[[NSBundle mainBundle] appStoreReceiptURL]]
An example of this working for both iOS and OS X to get the receipt and sending it to a server for verification (with a macro set for the OS X build):
NSData *tr ;
#ifdef OSX
tr = [NSData dataWithContentsOfURL:[[NSBundle mainBundle] appStoreReceiptURL]] ;
#else
tr = [transaction transactionReceipt];
#endif
NSString *jsonObjectString = [[self encode:(uint8_t *)[tr bytes] length:[tr length]] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *completeString = [NSString stringWithFormat:#"https://ssl.myserver.com/verify.php?%#", jsonObjectString];
NSURL *urlForValidation = [NSURL URLWithString:completeString];
NSMutableURLRequest *validationRequest = [[NSMutableURLRequest alloc] initWithURL:urlForValidation];
[validationRequest setHTTPMethod:#"GET"];
NSData *responseData = [NSURLConnection sendSynchronousRequest:validationRequest returningResponse:nil error:nil];
Be careful where verifying, the json object for OS X and iOS receipts are different so you'll likely need separate server side code for validation.
Update: Adding function to encode receipt for posting:
+ (NSString *)encode:(const uint8_t *)input length:(NSInteger)length {
static char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
NSMutableData *data = [NSMutableData dataWithLength:((length + 2) / 3) * 4];
uint8_t *output = (uint8_t *)data.mutableBytes;
for (NSInteger i = 0; i < length; i += 3) {
NSInteger value = 0;
for (NSInteger j = i; j < (i + 3); j++) {
value <<= 8;
if (j < length) {
value |= (0xFF & input[j]);
}
}
NSInteger index = (i / 3) * 4;
output[index + 0] = table[(value >> 18) & 0x3F];
output[index + 1] = table[(value >> 12) & 0x3F];
output[index + 2] = (i + 1) < length ? table[(value >> 6) & 0x3F] : '=';
output[index + 3] = (i + 2) < length ? table[(value >> 0) & 0x3F] : '=';
}
return [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
}
I class-dumped StoreKit to find out if this method was present and it is. Here is the header:
#interface SKPaymentTransaction : NSObject
{
id _internal;
}
- (id)init;
- (id)initWithDictionary:(id)arg1;
- (id)initWithPayment:(id)arg1;
- (void)dealloc;
#property(readonly) NSError *error;
#property(readonly) SKPaymentTransaction *originalTransaction;
#property(readonly) SKPayment *payment;
#property(readonly) NSDate *transactionDate;
#property(readonly) NSString *transactionIdentifier;
- (id)transactionReceipt;
#property(readonly) long long transactionState;
- (BOOL)canMergeWithTransaction:(id)arg1;
- (id)matchingIdentifier;
- (BOOL)mergeWithTransaction:(id)arg1;
- (id)_transactionIdentifier;
#end
You can use this method with [transaction transactionReceipt] (and get a warning). Apple may or may not consider this use of a private method and reject your application; but, for testing purposes, it is there.
According to Apple's official 10.7 documentation of SKPaymentTransaction, there is no transactionReceipt property.
Now i need to change the alignment of a paragraph in a nstextview without select it ,so i need to know the range of the current range of the paragraph?
I have a subclass of NSTextView so you need to access textStorage and selectedRange different than [self textStorage] and [self selectedRange].
NSTextStorage *textStorage = [self textStorage];
NSString *string = [textStorage string];
NSUInteger editEnd = [self selectedRange].location;
NSUInteger editStart = editEnd-[textStorage editedRange].length;
NSUInteger maxLength = [string length];
while (editStart > 0) {
unichar theChr = [string characterAtIndex:editStart-1];
if( theChr == '\n' || theChr == '\r' ) {
break;
}
--editStart;
}
while (editEnd < maxLength) {
unichar theChr = [string characterAtIndex:editEnd];
if( theChr == '\n' || theChr == '\r' ) {
break;
}
++editEnd;
}
NSRange paragraphRange = NSMakeRange(editStart, editEnd-editStart);
Here's a shortcut:
NSRange paragraphRange = [textView.textStorage.string paragraphRangeForRange: [textView selectedRange]];
First, get the range where the cursor stayed through [textView selectedRange]
Then you can get the line range through - (NSRange)lineRangeForRange:(NSRange)range of [textView string]
Here is a example code:
NSRange sel = [textView selectedRange];
NSString *viewContent = [textView string];
NSRange lineRange = [viewContent lineRangeForRange:NSMakeRange(sel.location,0)];
detail in there.
How to get the selected line range of NSTextView?
(have searched, but not been able to find a simple solution to this one either here, or in Cocoa docs)
Q. How can I trim all leading whitespace only from an NSString? (i.e. leaving any other whitespace intact.)
Unfortunately, for my purposes, NSString's stringByTrimmingCharactersInSet method works on both leading and trailing.
Mac OS X 10.4 compatibility needed, manual GC.
This creates an NSString category to do what you need. With this, you can call NSString *newString = [mystring stringByTrimmingLeadingWhitespace]; to get a copy minus leading whitespace. (Code is untested, may require some minor debugging.)
#interface NSString (trimLeadingWhitespace)
-(NSString*)stringByTrimmingLeadingWhitespace;
#end
#implementation NSString (trimLeadingWhitespace)
-(NSString*)stringByTrimmingLeadingWhitespace {
NSInteger i = 0;
while ((i < [self length])
&& [[NSCharacterSet whitespaceCharacterSet] characterIsMember:[self characterAtIndex:i]]) {
i++;
}
return [self substringFromIndex:i];
}
#end
This is another solution using Regular Expressions (requires iOS 3.2):
NSRange range = [string rangeOfString:#"^\\s*" options:NSRegularExpressionSearch];
NSString *result = [string stringByReplacingCharactersInRange:range withString:#""];
And if you want to trim the trailing whitespaces only you can use #"\\s*$" instead.
This code is taking blanks.
NSString *trimmedText = [strResult stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
NSLog(#"%#",trimmedText);
Here is a very efficient (uses CoreFoundation) way of doing it (Taken from kissxml):
- (NSString *)trimWhitespace {
NSMutableString *mStr = [self mutableCopy];
CFStringTrimWhitespace((CFMutableStringRef)mStr);
NSString *result = [mStr copy];
[mStr release];
return [result autorelease];
}
NSString *myText = #" foo ";
NSString *trimmedText = [myText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSLog(#"old = [%#], trimmed = [%#]", myText, trimmedText);
Here's what I would do, and it doesn't involve categories!
NSString* outputString = inputString;
NSRange range = [inputString rangeOfCharacterFromSet: [NSCharacterSet whitespaceCharacterSet]
options:0];
if (range.location == 0)
outputString = [inputString substringFromIndex: range.location + range.length];
This is much less code.
I didn't really have much time to test this, and I'm not sure if 10.4 contains the UTF8String method for NSString, but here's how I'd do it:
NSString+Trimming.h
#import <Foundation/Foundation.h>
#interface NSString (Trimming)
-(NSString *) stringByTrimmingWhitespaceFromFront;
#end
NSString+Trimming.m
#import "NSString+Trimming.h"
#implementation NSString (Trimming)
-(NSString *) stringByTrimmingWhitespaceFromFront
{
const char *cStringValue = [self UTF8String];
int i;
for (i = 0; cStringValue[i] != '\0' && isspace(cStringValue[i]); i++);
return [self substringFromIndex:i];
}
#end
It may not be the most efficient way of doing this but it should work.
str = [str stringByReplacingOccurrencesOfString:#" " withString:#""];