A light-weight Objective-C category that adds a mutable dictionary for arbitrary, ad-hoc properties that can be associated with any object. The dictionary, called properties, is created just-in-time (the first time it's accessed).
For any object, you can now set an ad-hoc property without prior declaration:
someObject.properties[@"someKey"] = someOtherObject;Ever wished you could attach an object to a standard class without subclassing? Now you can:
#import <NSObject+AssociatedDictionary.h>
:
UIButton *deleteButton;
UITextField *accountField;
:
deleteButton.properties[@"confirmationMessage"] = @"Are you sure you want to do this?";
accountField.properties[@"inputMask"] = @"99-99999-9";
accountField.properties[@"required"] = @YES;You can even set properties like these directly in Xcode's interface builder, using key paths and dot notation:
If NSObject+AssociatedDictionary.m is in your project, the UI loader will automatically set the properties for you. Without any additional initialization code, you'll be able to access them like this:
if (!accountField.hasText && [accountField.properties[@"required"] boolValue]) {
accountField.backgroundColor = accountField.properties[@"alertColor"];
[self alert:accountField.properties[@"alertMessage"]];
}Install via Cocoapods. Here's a sample Podfile:
pod 'NSObject+AssociatedDictionary'
Alternatively, just drop the two files (NSObject+AssociatedDictionary.m and NSObject+AssociatedDictionary.h) into your project tree.
Vikram Kriplaney
NSObject+AssociatedDictionary is available under the MIT license. See the LICENSE file for more info.