Make UIColor support hex color codes

UIColor+PXExtensions.h

//
//  UIColor+PXExtensions.h
//  Creates UIColor from hex string. "#" prefix is optional. Supports 3 and 6 hex digits.
//  Originally from http://pixelchild.com.au/post/12785987198/how-to-convert-a-html-hex-string-into-uicolor-with
//  But that link seems to be broken.
//  Revived by Thongchai Kolyutsakul (21 May 2015).
//
//  USAGE:  UIColor *mycolor = [UIColor pxColorWithHexValue:@"#BADA55"];
//          UIColor *mycolor = [UIColor pxColorWithHexValue:@"FFFFFF"];
//          UIColor *mycolor = [UIColor pxColorWithHexValue:@"1AD"];
//

#import <UIKit/UIKit.h>

@interface UIColor (UIColor_PXExtensions)
+ (UIColor*)pxColorWithHexValue:(NSString*)hexValue;
@end

UIColor+PXExtensions.m

//
//  UIColor+PXExtensions.m
//

#import "UIColor+UIColor_PXExtensions.h"

@implementation UIColor (UIColor_PXExtensions)

+ (UIColor*)pxColorWithHexValue:(NSString*)hexValue
{
    //Default
    UIColor *defaultResult = [UIColor blackColor];
    
    //Strip prefixed # hash
    if ([hexValue hasPrefix:@"#"] && [hexValue length] > 1) {
        hexValue = [hexValue substringFromIndex:1];
    }
    
    //Determine if 3 or 6 digits
    NSUInteger componentLength = 0;
    if ([hexValue length] == 3)
    {
        componentLength = 1;
    }
    else if ([hexValue length] == 6)
    {
        componentLength = 2;
    }
    else
    {
        return defaultResult;
    }
    
    BOOL isValid = YES;
    CGFloat components[3];
    
    //Seperate the R,G,B values
    for (NSUInteger i = 0; i < 3; i++) {
        NSString *component = [hexValue substringWithRange:NSMakeRange(componentLength * i, componentLength)];
        if (componentLength == 1) {
            component = [component stringByAppendingString:component];
        }
        NSScanner *scanner = [NSScanner scannerWithString:component];
        unsigned int value;
        isValid &= [scanner scanHexInt:&value];
        components[i] = (CGFloat)value / 256.0f;
    }
    
    if (!isValid) {
        return defaultResult;
    }
    
    return [UIColor colorWithRed:components[0]
                           green:components[1]
                            blue:components[2]
                           alpha:1.0];
}

@end