RestKit/Code/Support/NSDictionary+RKAdditions.m

//
//  NSDictionary+RKAdditions.m
//  RestKit
//
//  Created by Blake Watters on 9/5/10.
//  Copyright (c) 2009-2012 RestKit. All rights reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

#import "NSDictionary+RKAdditions.h"
#import "NSString+RKAdditions.h"
#import "RKFixCategoryBug.h"

RK_FIX_CATEGORY_BUG(NSDictionary_RKAdditions)

@implementation NSDictionary (RKAdditions)

+ (id)dictionaryWithKeysAndObjects:(id)firstKey, ... {
    va_list args;
    va_start(args, firstKey);
    NSMutableArray* keys = [NSMutableArray array];
    NSMutableArray* values = [NSMutableArray array];
    for (id key = firstKey; key != nil; key = va_arg(args, id)) {
        id value = va_arg(args, id);
        [keys addObject:key];
        [values addObject:value];
    }
    va_end(args);

    return [self dictionaryWithObjects:values forKeys:keys];
}

- (NSDictionary *)dictionaryByReplacingPercentEscapesInEntries {
    NSMutableDictionary *results = [NSMutableDictionary dictionaryWithCapacity:[self count]];
    [self enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop)
     {
         NSString *escapedKey = [key stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
         id escapedValue = value;
         if ([value respondsToSelector:@selector(stringByReplacingPercentEscapesUsingEncoding:)])
             escapedValue = [value stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
         [results setObject:escapedValue forKey:escapedKey];
     }];
    return results;
}

// TODO: Unit tests...
+ (NSDictionary *)dictionaryWithURLEncodedString:(NSString *)URLEncodedString {
    NSMutableDictionary *queryComponents = [NSMutableDictionary dictionary];
    for(NSString *keyValuePairString in [URLEncodedString componentsSeparatedByString:@"&"]) {
        NSArray *keyValuePairArray = [keyValuePairString componentsSeparatedByString:@"="];
        if ([keyValuePairArray count] < 2) continue; // Verify that there is at least one key, and at least one value.  Ignore extra = signs
        NSString *key = [[keyValuePairArray objectAtIndex:0] stringByReplacingURLEncoding];
        NSString *value = [[keyValuePairArray objectAtIndex:1] stringByReplacingURLEncoding];

        // URL spec says that multiple values are allowed per key
        id results = [queryComponents objectForKey:key];
        if(results) {
            if ([results isKindOfClass:[NSMutableArray class]]) {
                [(NSMutableArray *)results addObject:value];
            } else {
                // On second occurrence of the key, convert into an array
                NSMutableArray *values = [NSMutableArray arrayWithObjects:results, value, nil];
                [queryComponents setObject:values forKey:key];
            }
        } else {
            [queryComponents setObject:value forKey:key];
        }
        [results addObject:value];
    }
    return queryComponents;
}

- (void)URLEncodePart:(NSMutableArray*)parts path:(NSString*)path value:(id)value {
    NSString *encodedPart = [[value description] stringByAddingURLEncoding];
    [parts addObject:[NSString stringWithFormat: @"%@=%@", path, encodedPart]];
}

- (void)URLEncodeParts:(NSMutableArray*)parts path:(NSString*)inPath {
    [self enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop) {
        NSString *encodedKey = [[key description] stringByAddingURLEncoding];
        NSString *path = inPath ? [inPath stringByAppendingFormat:@"[%@]", encodedKey] : encodedKey;

        if ([value isKindOfClass:[NSArray class]]) {
            for (id item in value) {
                if ([item isKindOfClass:[NSDictionary class]] || [item isKindOfClass:[NSMutableDictionary class]]) {
                    [item URLEncodeParts:parts path:[path stringByAppendingString:@"[]"]];
                } else {
                    [self URLEncodePart:parts path:[path stringByAppendingString:@"[]"] value:item];
                }

            }
        } else if([value isKindOfClass:[NSDictionary class]] || [value isKindOfClass:[NSMutableDictionary class]]) {
            [value URLEncodeParts:parts path:path];
        }
        else {
            [self URLEncodePart:parts path:path value:value];
        }
    }];
}

- (NSString *)stringWithURLEncodedEntries {
    NSMutableArray* parts = [NSMutableArray array];
    [self URLEncodeParts:parts path:nil];
    return [parts componentsJoinedByString:@"&"];
}

- (NSString *)URLEncodedString {
    return [self stringWithURLEncodedEntries];
}

@end