NSDictionary+URLEncoding.m

//
// Copyright (c) 2012, Able Pear Software Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// - Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// - Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
//         SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Original source:
// http://blog.ablepear.com/2008/12/urlencoding-category-for-nsdictionary.html

#import "NSDictionary+URLEncoding.h"

// helper function: get the string form of any object
static NSString *toString(id object) {
    return [NSString stringWithFormat: @"%@", object];
}

// helper function: get the url encoded string form of any object
static NSString *urlEncode(id object) {
    NSString *string = toString(object);
    return [string stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
}

@implementation NSDictionary (UrlEncoding)

-(NSString*) urlEncodedString {
    NSMutableArray *parts = [NSMutableArray array];
    for (id key in self) {
        id value = [self objectForKey: key];
        NSString *part = [NSString stringWithFormat: @"%@=%@", urlEncode(key), urlEncode(value)];
        [parts addObject: part];
    }
    return [parts componentsJoinedByString: @"&"];
}

@end