MPTidbits, by Matt Patenaude

A set of very small categories for NSString, NSMutableString, NSArray, and NSDictionary that add a few sorely lacking features (isEmpty and containsKey: methods, for instance).

Documentation

Most of the methods are relatively self-explanatory, but this should clear things up for those of slightly greater ambiguity.

Including the Source

You can include MPTidbits in your project by simply copying all five source files into your project, and then importing the global header file in any file in which you want to use an MPTidbits method:

#import "MPTidbits.h"

Useful Functions

These functions can be found in MPFunctions.h.

• NSString *MPHexStringFromBytes(void *bytes, NSUInteger len)

  Returns a hexadecimal NSString representation of the data referenced by bytes. len should be the length of the data (the number of bytes).

NSString Methods

These methods can be found in NSString+MPTidbits.h.

• - (BOOL)isEmpty

  Returns YES only if the receiver is either empty (no characters), or contains only whitespace characters.

• - (BOOL)isEmptyIgnoringWhitespace:(BOOL)ignoreWhitespace

  If ignoreWhitespace is YES, returns YES only if the receiver is either empty (no characters), or contains only whitespace characters. If ignoreWhitespace is NO, returns YES only if the receiver is empty (no characters) -- it does not ignore whitespace characters.

• - (NSString *)stringByTrimmingWhitespace

  Returns an NSString object identical to the receiver except that any leading or trailing whitespace characters (the characters in the set returned by NSCharacterSet's +whitespaceCharacterSet) will be stripped.

• - (NSString *)MD5Hash

  Returns an NSString object that contains a 32-character hexadecimal representation of the receiver's MD5 hash. This method uses the functions of Foundation's CommonCrypto library, which means that your project does not have to link against an outside library (eg, OpenSSL).

• - (NSString *)SHA1Hash

  Returns an NSString object that contains a 40-character hexadecimal representation of the receiver's SHA-1 hash. This method uses the functions of Foundation's CommonCrypto library, which means that your project does not have to link against an outside library (eg, OpenSSL).

NSMutableString Methods

These methods can be found in NSString+MPTidbits.h.

• - (void)trimCharactersInSet:(NSCharacterSet *)aCharacterSet

  Strips leading and trailing characters from the receiver that belong to aCharacterSet. In contrast to NSString's -stringByTrimmingCharactersInSet:, this method operates on the receiver in place.

• - (void)trimWhitespace

  Strips leading and trailing whitespace characters (the characters in the set returned by NSCharacterSet's +whitespaceCharacterSet) from the receiver. In contrast to the above -stringByTrimmingWhitespace, this method operates on the receiver in place.

NSArray Methods

These methods can be found in NSCollections+MPTidbits.h.

• - (BOOL)isEmpty

  Returns YES only if the receiver contains no objects: the equivalent of ([receiver count] == 0).

NSDictionary Methods

These methods can be found in NSCollections+MPTidbits.h.

• - (BOOL)isEmpty

  Returns YES only if the receiver contains no objects: the equivalent of ([receiver count] == 0).

• - (BOOL)containsKey:(NSString *)aKey

  Returns YES only if the key aKey has an associated object in the receiver.

• - (BOOL)containsKey:(NSString *)aKey allowEmptyValue:(BOOL)allowEmpty

  If allowEmpty is YES, returns YES only if the key aKey has an associated object in the receiver. If allowEmpty is NO, returns YES only if the key aKey has an associated object in the receiver, and that object is neither the NSNull object, nor does it return YES to an isEmpty message (if the object responds to it). This method is useful if you want to quickly check if a key both exists, and is not an empty string, for example.

License

MPTidbits is licensed under the MIT license, excerpted below.

Copyright (C) 2008 - 09 Matt Patenaude.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.