JSON Syntax Highlight

Add syntax highlighting to JSON objects in Objective C for both Cocoa and iOS without using HTML

Requires ARC

Installation

CocoaPods

Add JSONSyntaxHighlight to your Podfile

pod 'JSONSyntaxHighlight'

Manually

• Copy JSONSyntaxHighlight.m and JSONSyntaxHighlight.h to your porject
• iOS
  • Add UIKit.framework to your project
• Mac
  • Add AppKit.framework to your project

Example

Clone this repository and open the Xcode project to see the Mac and iOS examples

Import this library

// Pods
#import <JSONSyntaxHighlight/JSONSyntaxHighlight.h>
// - or -
// Manually
#import "JSONSyntaxHighlight.h"

Create the JSONSyntaxHighlight object

id JSONObj = @{
  @"name": @"dave"
};

JSONSyntaxHighlight *jsh = [[JSONSyntaxHighlight alloc] initWithJSON:JSONObj];

Basic highlighting

NSAttributedString *s;

s = [jsh highlightJSON];
// s => an NSAttributedString with the JSON highlighted in pretty print format

s = [jsh highlightJSONWithPrettyPrint:NO];
// s => same as above, but compressed JSON is returned

Advanced highlighting

jsh.nonStringAttributes = @{NSForegroundColorAttributeName: [JSONSyntaxHighlight colorWithRGB:0xffffff]};
jsh.stringAttributes = @{NSForegroundColorAttributeName: [JSONSyntaxHighlight colorWithRGB:0x00ff00]};
jsh.keyAttributes = @{NSForegroundColorAttributeName: [JSONSyntaxHighlight colorWithRGB:0x0000ff]};
s = [jsh highlightJSON];
// s => an NSAttributedString with the JSON highlighted in pretty print format
// using the colors specified above

Event driven API

NSMutableString *json = [[NSMutableString alloc] initWithString:@""];
[jsh enumerateMatchesWithIndentBlock:
 // The indent
 ^(NSRange range, NSString *s) {
     [json appendAttributedString:s];
 }
                             keyBlock:
 // The key (with quotes and colon)
 ^(NSRange range, NSString *s) {
     [json appendAttributedString:s];
 }
                           valueBlock:
 // The value
 ^(NSRange range, NSString *s) {
     [json appendAttributedString:s];
 }
                             endBlock:
 // The final comma, or ending character
 ^(NSRange range, NSString *s) {
     [json appendAttributedString:s];
     [json appendAttributedString:@"\n"];
 }];
// json => a pretty printed JSON string

Usage

- (JSONSyntaxHighlight *)initWithJSON:(id)JSON;

Create a JSONSyntaxHighlight object given a JSON object (NSDictionary, NSArray, etc.)

@property (readonly, nonatomic, strong) id JSON;
@property (readonly, nonatomic, strong) NSString *parsedJSON;

JSON is the unmodified JSON object, and parsedJSON is the stringified pretty printed JSON string

- (NSAttributedString *)highlightJSON;
- (NSAttributedString *)highlightJSONWithPrettyPrint:(BOOL)prettyPrint;

Return an NSAttributedString with the highlighted JSON in an optionally pretty printed format. If unspecified, pretty printing is the default

@property (nonatomic, strong) NSDictionary *keyAttributes;
@property (nonatomic, strong) NSDictionary *stringAttributes;
@property (nonatomic, strong) NSDictionary *nonStringAttributes;

Set the attributes to be used for the NSAttributedString for the JSON keys and values (both string and non-string)

- (void)enumerateMatchesWithIndentBlock:(void(^)(NSRange, NSString*))indentBlock
                               keyBlock:(void(^)(NSRange, NSString*))keyBlock
                             valueBlock:(void(^)(NSRange, NSString*))valueBlock
                               endBlock:(void(^)(NSRange, NSString*))endBlock

Fire a callback for every key item found in the parsed JSON, each callback is fired with the NSRange the substring appears in self.parsedJSON, as well as the NSString at that location.

An example JSON file with each "key item" is illustrated below

{
     "name": "dave",
+---++------++----++
|    |       |     |
|    |       |     +-->end    (may be empty)
|    |       +-------->value  (will have quotes if string)
|    +---------------->key    (will have quotes and colon)
+--------------------->indent (leading spaces)
     "age": 24
+---++-----++++
|    |      | |
|    |      | +------->end    @""
|    |      +--------->value  @"24"
|    +---------------->key    @"\"age\":"
+--------------------->indent @"    "
}
+
|
+--------------------->end    @"}"

+ (Color *)colorWithRGB:(NSInteger)rgbValue;
+ (Color *)colorWithRGB:(NSInteger)rgbValue alpha:(CGFloat)alpha;

These functions can be used to return an NSColor or UIColor object (as appropriate) based on the given rgbValue

Todo

• The regex parsing of JSON is ugly... maybe a custom stringify function should be used

License

MIT License