ios - how - xcode objective c class extension




How do I create a category in Xcode 6 or higher? (6)

I want to create a category on UIColor in my app using Xcode 6. But the thing is that in Xcode 6 there is no Objective-C category file template.

Is there any option to create a category in Xcode 6?


Xcode6-Beta5 update

The interface has now changed and it's possible to add a Category directly from the New > File window.

See unmircea's answer.


I was surprised myself, and I guess because of Swift they forgot about good old Objective-C.

You have two options:

  1. Create an Objective-C class with the category name, example UIView+Powerups, then manually change the interface to match the one of category. Note that the snippet for the category interface and implementation is still working, so that's extra easy: type @interface-category and @implementation-category.

  2. Import it from Xcode 5! Use this command:

    cp -r /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Xcode/Templates/File\ Templates/Cocoa\ Touch/Objective-C\ category.xctemplate /Applications/Xcode6-Beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Xcode/Templates/File\ Templates/Source/
    

    Close and reopen Xcode 6 and you'll find "Objective-C Category" in the wizard for the new file.


Extending unmircea's fantastic answer re: how to create a custom category to implement a custom UIColor palette, you could create a category.

Once you've created your category (in this example, it's a category called ColorPalette of class UIColor), you'll have a header and an implementation file.

UIColor+ColorPalette.h

#import <UIKit/UIKit.h>

@interface UIColor (ColorPalette)

// Your custom colors

+ (UIColor *) customRedButtonColor;
+ (UIColor *) customGreenButtonColor;

@end

UIColor+ColorPalette.m

#import "UIColor+ColorPalette.h"

@implementation UIColor (ColorPalette)

// Button Colors

+ (UIColor *) customRedButtonColor {
    return [UIColor colorWithRed:178.0/255.0 green:25.0/255.0 blue:0.0/255.0 alpha:1.0];
}

+ (UIColor *) customGreenButtonColor {
    return [UIColor colorWithRed:20.0/255.0 green:158.0/255.0 blue:96.0/255.0 alpha:1.0];
}

To use your custom color palette, just import the header into the class where you'd like to implement your custom colors:

#import "UIColor+ColorPalette.h"

and call the color as you would a standard color like redColor, greenColor, or blueColor.

Here's a link to a slightly more in-depth discussion of creating a custom palette.

Additionally, here is a tool to help you select the custom color values


There is no predefined template to create category in Xcode 6 beta(for time being),they may add this option later. As a work around you can create a Cocoa Touch Class(its not proper i know but no other way) named UIImage+Additions(ClassName+CategoryName) and override its interface and implementation some thing like

UIImage+Additions.h

#import <UIKit/UIKit.h>

@interface UIImage(Additions)

+(void)testMethod;

@end 

UIImage+Additions.m

#import "UIImage+Additions.h"

@implementation UIImage (Additions)

+(void)testMethod
{

}

@end

Edit
This answer was written before finding a way of creating category in the Xcode 6 beta. Check unmircea's answer for the right way of creating category


They didn't forget. They just moved it without telling anyone.

  1. Click File -> New -> File

  2. Select Objective-C file under Sources in iOS or Mac OS respectively and Click Next

  3. Now under File Type: choose either Category, Protocol, or Extension

PS. Under File Name: whatever you type here will be either the Category, Protocol, or Extension Name.


You can create "extension" file like NSString+Helper:

1: File → New → File... or use ⌘N.

2: Name NSString+Helper (For example)

3: create the file

4: Remove the code from file

5: add 

extension NSString {


}

Done. enjoy coding






xcode6