Related
I am getting the following crash on crashlytics.
Fatal Exception: NSUnknownKeyException
[<__NSCFString 0x1742aeb80> valueForUndefinedKey:]: this class is not key value coding-compliant for the key url.
This is where the crash occurred for some of the users.
id url = [[json[#"data"]valueForKey:#"value"]valueForKey:#"url"];
I'm not sure what is the best way to prevent this crash. I believe this is because json[#"data"] is an NSString in certain cases. So I believe I should check if this is an NSDictionary like this.
if ([json[#"data"] isKindOfClass:[NSDictionary class]]) {
id url = [[json[#"data"]valueForKey:#"value"]valueForKey:#"url"];
}
Any tips or suggestions are appreciated.
This is my end result after getting answers from here. Does this look okay? I didn't include all my code at first to keep things simple.
if ([json isKindOfClass:[NSDictionary class]]) {
id url = nil;
id type = nil;
NSDictionary *data = json[#"data"];
if ([data isKindOfClass:[NSDictionary class]]) {
type = data[#"type"];
NSDictionary *value = data[#"value"];
if ([value isKindOfClass:[NSArray class]]) {
url = [value valueForKey:#"url"];
}
if ([type isKindOfClass:[NSString class]] && [url isKindOfClass:[NSArray class]] && [url count] != 0) {
// do stuff
}
}
}
You should check NSDictionary one by one to prevent crash. Try my code below
NSDictionary *dictionary = json[#"data"];
NSString *output = #"";
if ([dictionary isKindOfClass:[NSDictionary class]]) {
dictionary = dictionary[#"value"];
if ([dictionary isKindOfClass:[NSDictionary class]]) {
output = dictionary[#"url"];
}
}
NSLog(#"%#", output);
You got crash because of calling valueForKey method on a NSString value. If someone says the reason for crash is call valueForKey when dictionary doesn't have this key, it's wrong. For more information Sending a message to nil in Objective-C
[dictionary isKindOfClass:[NSDictionary class]] always return NO if dictionary is nil so don't need to check dictionary in if statement. It's unnessary.
Your error means that json[#"data"]valueForKey:#"value"] doesn't NSDictionarry, so it have no #"url" key.
valueForKey it's KVC method, use objectForKey for dictionaries, and add more checks like:
id url = nil;
NSDictionary *data = [json objectForkey:#"data"];
if ([data isKindOfClass:[NSDictionary class]]) {
NSDictionary *value = [data objectForKey:#"value"];
if ([value isKindOfClass:[NSDictionary class]]) {
url = [value objectForKey:#"url"];
}
}
With all the URL-handling objects lying around in the standard Cocoa libraries (NSURL, NSMutableURL, NSMutableURLRequest, etc), I know I must be overlooking an easy way to programmatically compose a GET request.
Currently I'm manually appending "?" followed by name value pairs joined by "&", but all of my name and value pairs need to be manually encoded so NSMutableURLRequest doesn't fail entirely when it tries to connect to the URL.
This feels like something I should be able to use a pre-baked API for.... is there anything out of the box to append an NSDictionary of query parameters to an NSURL? Is there another way I should approach this?
Introduced in iOS8 and OS X 10.10 is NSURLQueryItem, which can be used to build queries. From the docs on NSURLQueryItem:
An NSURLQueryItem object represents a single name/value pair for an item in the query portion of a URL. You use query items with the queryItems property of an NSURLComponents object.
To create one use the designated initializer queryItemWithName:value: and then add them to NSURLComponents to generate an NSURL. For example:
NSURLComponents *components = [NSURLComponents componentsWithString:#"http://stackoverflow.com"];
NSURLQueryItem *search = [NSURLQueryItem queryItemWithName:#"q" value:#"ios"];
NSURLQueryItem *count = [NSURLQueryItem queryItemWithName:#"count" value:#"10"];
components.queryItems = #[ search, count ];
NSURL *url = components.URL; // http://stackoverflow.com?q=ios&count=10
Notice that the question mark and ampersand are automatically handled. Creating an NSURL from a dictionary of parameters is as simple as:
NSDictionary *queryDictionary = #{ #"q": #"ios", #"count": #"10" };
NSMutableArray *queryItems = [NSMutableArray array];
for (NSString *key in queryDictionary) {
[queryItems addObject:[NSURLQueryItem queryItemWithName:key value:queryDictionary[key]]];
}
components.queryItems = queryItems;
I've also written a blog post on how to build URLs with NSURLComponents and NSURLQueryItems.
You can create a category for NSDictionary to do this -- there isn't a standard way in the Cocoa library that I could find either. The code that I use looks like this:
// file "NSDictionary+UrlEncoding.h"
#import <cocoa/cocoa.h>
#interface NSDictionary (UrlEncoding)
-(NSString*) urlEncodedString;
#end
with this implementation:
// file "NSDictionary+UrlEncoding.m"
#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
I think the code's pretty straightforward, but I discuss it in some more detail at http://blog.ablepear.com/2008/12/urlencoding-category-for-nsdictionary.html.
I wanted to use Chris's answer, but it wasn't written for Automatic Reference Counting (ARC) so I updated it. I thought I'd paste my solution in case anyone else has this same issue. Note: replace self with the instance or class name where appropriate.
+(NSString*)urlEscapeString:(NSString *)unencodedString
{
CFStringRef originalStringRef = (__bridge_retained CFStringRef)unencodedString;
NSString *s = (__bridge_transfer NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,originalStringRef, NULL, (CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ", kCFStringEncodingUTF8);
CFRelease(originalStringRef);
return s;
}
+(NSString*)addQueryStringToUrlString:(NSString *)urlString withDictionary:(NSDictionary *)dictionary
{
NSMutableString *urlWithQuerystring = [[NSMutableString alloc] initWithString:urlString];
for (id key in dictionary) {
NSString *keyString = [key description];
NSString *valueString = [[dictionary objectForKey:key] description];
if ([urlWithQuerystring rangeOfString:#"?"].location == NSNotFound) {
[urlWithQuerystring appendFormat:#"?%#=%#", [self urlEscapeString:keyString], [self urlEscapeString:valueString]];
} else {
[urlWithQuerystring appendFormat:#"&%#=%#", [self urlEscapeString:keyString], [self urlEscapeString:valueString]];
}
}
return urlWithQuerystring;
}
The other answers work great if the values are strings, however if the values are dictionaries or arrays then this code will handle that.
Its important to note that there is no standard way of passing an array/dictionary via the query string but PHP handles this output just fine
-(NSString *)serializeParams:(NSDictionary *)params {
/*
Convert an NSDictionary to a query string
*/
NSMutableArray* pairs = [NSMutableArray array];
for (NSString* key in [params keyEnumerator]) {
id value = [params objectForKey:key];
if ([value isKindOfClass:[NSDictionary class]]) {
for (NSString *subKey in value) {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)[value objectForKey:subKey],
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#[%#]=%#", key, subKey, escaped_value]];
}
} else if ([value isKindOfClass:[NSArray class]]) {
for (NSString *subValue in value) {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)subValue,
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#[]=%#", key, escaped_value]];
}
} else {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)[params objectForKey:key],
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#=%#", key, escaped_value]];
[escaped_value release];
}
}
return [pairs componentsJoinedByString:#"&"];
}
Examples
[foo] => bar
[translations] =>
{
[one] => uno
[two] => dos
[three] => tres
}
foo=bar&translations[one]=uno&translations[two]=dos&translations[three]=tres
[foo] => bar
[translations] =>
{
uno
dos
tres
}
foo=bar&translations[]=uno&translations[]=dos&translations[]=tres
I refactored and converted to ARC answer by AlBeebe
- (NSString *)serializeParams:(NSDictionary *)params {
NSMutableArray *pairs = NSMutableArray.array;
for (NSString *key in params.keyEnumerator) {
id value = params[key];
if ([value isKindOfClass:[NSDictionary class]])
for (NSString *subKey in value)
[pairs addObject:[NSString stringWithFormat:#"%#[%#]=%#", key, subKey, [self escapeValueForURLParameter:[value objectForKey:subKey]]]];
else if ([value isKindOfClass:[NSArray class]])
for (NSString *subValue in value)
[pairs addObject:[NSString stringWithFormat:#"%#[]=%#", key, [self escapeValueForURLParameter:subValue]]];
else
[pairs addObject:[NSString stringWithFormat:#"%#=%#", key, [self escapeValueForURLParameter:value]]];
}
return [pairs componentsJoinedByString:#"&"];
}
- (NSString *)escapeValueForURLParameter:(NSString *)valueToEscape {
return (__bridge_transfer NSString *) CFURLCreateStringByAddingPercentEscapes(NULL, (__bridge CFStringRef) valueToEscape,
NULL, (CFStringRef) #"!*'();:#&=+$,/?%#[]", kCFStringEncodingUTF8);
}
If you are already using AFNetworking (as was the case with me), you can use it's class AFHTTPRequestSerializer to create the required NSURLRequest.
[[AFHTTPRequestSerializer serializer] requestWithMethod:#"GET" URLString:#"YOUR_URL" parameters:#{PARAMS} error:nil];
In case you only require the URL for your work, use NSURLRequest.URL.
Here is a simple example in Swift (iOS8+):
private let kSNStockInfoFetchRequestPath: String = "http://dev.markitondemand.com/Api/v2/Quote/json"
private func SNStockInfoFetchRequestURL(symbol:String) -> NSURL? {
if let components = NSURLComponents(string:kSNStockInfoFetchRequestPath) {
components.queryItems = [NSURLQueryItem(name:"symbol", value:symbol)]
return components.URL
}
return nil
}
I took Joel's recommendation of using URLQueryItems and turned into a Swift Extension (Swift 3)
extension URL
{
/// Creates an NSURL with url-encoded parameters.
init?(string : String, parameters : [String : String])
{
guard var components = URLComponents(string: string) else { return nil }
components.queryItems = parameters.map { return URLQueryItem(name: $0, value: $1) }
guard let url = components.url else { return nil }
// Kinda redundant, but we need to call init.
self.init(string: url.absoluteString)
}
}
(The self.init method is kinda cheesy, but there was no NSURL init with components)
Can be used as
URL(string: "http://www.google.com/", parameters: ["q" : "search me"])
I've got another solution:
http://splinter.com.au/build-a-url-query-string-in-obj-c-from-a-dict
+(NSString*)urlEscape:(NSString *)unencodedString {
NSString *s = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)unencodedString,
NULL,
(CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ",
kCFStringEncodingUTF8);
return [s autorelease]; // Due to the 'create rule' we own the above and must autorelease it
}
// Put a query string onto the end of a url
+(NSString*)addQueryStringToUrl:(NSString *)url params:(NSDictionary *)params {
NSMutableString *urlWithQuerystring = [[[NSMutableString alloc] initWithString:url] autorelease];
// Convert the params into a query string
if (params) {
for(id key in params) {
NSString *sKey = [key description];
NSString *sVal = [[params objectForKey:key] description];
// Do we need to add ?k=v or &k=v ?
if ([urlWithQuerystring rangeOfString:#"?"].location==NSNotFound) {
[urlWithQuerystring appendFormat:#"?%#=%#", [Http urlEscape:sKey], [Http urlEscape:sVal]];
} else {
[urlWithQuerystring appendFormat:#"&%#=%#", [Http urlEscape:sKey], [Http urlEscape:sVal]];
}
}
}
return urlWithQuerystring;
}
You can then use it like so:
NSDictionary *params = #{#"username":#"jim", #"password":#"abc123"};
NSString *urlWithQuerystring = [self addQueryStringToUrl:#"https://myapp.com/login" params:params];
-(NSString*)encodeDictionary:(NSDictionary*)dictionary{
NSMutableString *bodyData = [[NSMutableString alloc]init];
int i = 0;
for (NSString *key in dictionary.allKeys) {
i++;
[bodyData appendFormat:#"%#=",key];
NSString *value = [dictionary valueForKey:key];
NSString *newString = [value stringByReplacingOccurrencesOfString:#" " withString:#"+"];
[bodyData appendString:newString];
if (i < dictionary.allKeys.count) {
[bodyData appendString:#"&"];
}
}
return bodyData;
}
Yet another solution, if you use RestKit there's a function in RKURLEncodedSerialization called RKURLEncodedStringFromDictionaryWithEncoding that does exactly what you want.
Simple way of converting NSDictionary to url query string in Objective-c
Ex: first_name=Steve&middle_name=Gates&last_name=Jobs&address=Palo Alto, California
NSDictionary *sampleDictionary = #{#"first_name" : #"Steve",
#"middle_name" : #"Gates",
#"last_name" : #"Jobs",
#"address" : #"Palo Alto, California"};
NSMutableString *resultString = [NSMutableString string];
for (NSString* key in [sampleDictionary allKeys]){
if ([resultString length]>0)
[resultString appendString:#"&"];
[resultString appendFormat:#"%#=%#", key, [sampleDictionary objectForKey:key]];
}
NSLog(#"QueryString: %#", resultString);
Hope will help :)
If you are already using AFNetwork, you can use their built in serializer to to produce an encoded URL;
NSString *baseURL = #"https://api.app.com/parse";
NSDictionary *mutableParameters = [[NSMutableDictionary alloc] initWithObjectsAndKeys:#"true",#"option1", data, #"option2", token, #"token", #"3.0", #"app", nil];
NSURLRequest *request = [[AFHTTPRequestSerializer serializer] requestWithMethod:#"GET" URLString:baseURL parameters:mutableParameters error:nil];
NSString *urlPath = request.URL.absoluteString;
NSLog(#"%#", urlPath); // https://api.app.com/parse?option1=true&option2=datavalue&token=200%3ATEST%3AENCODE ....
Note; this is an extension to an above answer. The edit queue is full so cannot be added to the existing answer.
I'm curious, I currently have an NSDictionary where some values are set to an NSNull object thanks to the help of json-framework.
The aim is to strip all NSNull values and replace it with an empty string.
I'm sure someone has done this somewhere? No doubt it is probably a four liner and is simple, I am just far too burnt out to figure this out on my own.
I've made a few changes to Jacob's original answer to extend it to handle dictionaries and arrays stored within the original dictionary.
#import "NSDictionary+NullReplacement.h"
#import "NSArray+NullReplacement.h"
#implementation NSDictionary (NullReplacement)
- (NSDictionary *)dictionaryByReplacingNullsWithBlanks {
const NSMutableDictionary *replaced = [self mutableCopy];
const id nul = [NSNull null];
const NSString *blank = #"";
for (NSString *key in self) {
id object = [self objectForKey:key];
if (object == nul) [replaced setObject:blank forKey:key];
else if ([object isKindOfClass:[NSDictionary class]]) [replaced setObject:[object dictionaryByReplacingNullsWithBlanks] forKey:key];
else if ([object isKindOfClass:[NSArray class]]) [replaced setObject:[object arrayByReplacingNullsWithBlanks] forKey:key];
}
return [NSDictionary dictionaryWithDictionary:[replaced copy]];
}
#end
And there's also an array category of course:
#import "NSArray+NullReplacement.h"
#import "NSDictionary+NullReplacement.h"
#implementation NSArray (NullReplacement)
- (NSArray *)arrayByReplacingNullsWithBlanks {
NSMutableArray *replaced = [self mutableCopy];
const id nul = [NSNull null];
const NSString *blank = #"";
for (int idx = 0; idx < [replaced count]; idx++) {
id object = [replaced objectAtIndex:idx];
if (object == nul) [replaced replaceObjectAtIndex:idx withObject:blank];
else if ([object isKindOfClass:[NSDictionary class]]) [replaced replaceObjectAtIndex:idx withObject:[object dictionaryByReplacingNullsWithBlanks]];
else if ([object isKindOfClass:[NSArray class]]) [replaced replaceObjectAtIndex:idx withObject:[object arrayByReplacingNullsWithBlanks]];
}
return [replaced copy];
}
#end
With this, you can take any array or dictionary and recursively wipe out all the [NSNull null] instances.
P.S. For completion's sake, here are the header files:
#interface NSDictionary (NullReplacement)
- (NSDictionary *)dictionaryByReplacingNullsWithBlanks;
#end
And the array header:
#interface NSArray (NullReplacement)
- (NSArray *)arrayByReplacingNullsWithBlanks;
#end
Really simple:
#interface NSDictionary (JRAdditions)
- (NSDictionary *)dictionaryByReplacingNullsWithStrings;
#end
#implementation NSDictionary (JRAdditions)
- (NSDictionary *)dictionaryByReplacingNullsWithStrings {
const NSMutableDictionary *replaced = [self mutableCopy];
const id nul = [NSNull null];
const NSString *blank = #"";
for(NSString *key in self) {
const id object = [self objectForKey:key];
if(object == nul) {
//pointer comparison is way faster than -isKindOfClass:
//since [NSNull null] is a singleton, they'll all point to the same
//location in memory.
[replaced setObject:blank
forKey:key];
}
}
return [replaced copy];
}
#end
Usage:
NSDictionary *someDictThatHasNulls = ...;
NSDictionary *replacedDict = [someDictThatHasNulls dictionaryByReplacingNullsWithStrings];
Rolling through the dictionary hunting for NSNull is one way to tackle the problem, but I took a slightly lazier approach. Instead of nil you could assign an empty string, but the principle is the same.
CPJSONDictionary.h
#interface NSDictionary (CPJSONDictionary)
- (id)jsonObjectForKey:(id)aKey;
#end
CPJSONDictionary.m
#implementation NSDictionary (CPJSONDictionary)
- (id)jsonObjectForKey:(id)aKey {
id object = [self objectForKey:aKey];
if ([object isKindOfClass:[NSNull class]]) {
object = nil;
}
return object;
}
#end
I have tested Stakenborg solution. It works well, but it has following problem. If some object is expected to be number, for instance, converting it to NSNull can be a source of error.
I have create a new method to directly remove the NSNull entries. This way you only have to check that correspondant key exists.
Add in NSDictionary+NullReplacement
- (NSDictionary *)dictionaryByRemovingNulls{
const NSMutableDictionary *replaced = [self mutableCopy];
const id nul = [NSNull null];
for (NSString *key in self) {
id object = [self objectForKey:key];
if (object == nul) [replaced removeObjectForKey:key];
else if ([object isKindOfClass:[NSDictionary class]]) [replaced setObject:[object dictionaryByRemovingNulls] forKey:key];
else if ([object isKindOfClass:[NSArray class]]) [replaced setObject:[object arrayByRemovingNulls] forKey:key];
}
return [NSDictionary dictionaryWithDictionary:[replaced copy]];
}
And in NSArray+NullReplacement
- (NSArray *)arrayByRemovingNulls {
NSMutableArray *replaced = [self mutableCopy];
const id nul = [NSNull null];
for (int idx = [replaced count]-1; idx >=0; idx--) {
id object = [replaced objectAtIndex:idx];
if (object == nul) [replaced removeObjectAtIndex:idx];
else if ([object isKindOfClass:[NSDictionary class]]) [replaced replaceObjectAtIndex:idx withObject:[object dictionaryByRemovingNulls]];
else if ([object isKindOfClass:[NSArray class]]) [replaced replaceObjectAtIndex:idx withObject:[object arrayByRemovingNulls]];
}
return [replaced copy];
}
another variation:
NSDictionary * NewDictionaryReplacingNSNullWithEmptyNSString(NSDictionary * dict) {
NSMutableDictionary * const m = [dict mutableCopy];
NSString * const empty = #"";
id const nul = [NSNull null];
NSArray * const keys = [m allKeys];
for (NSUInteger idx = 0, count = [keys count]; idx < count; ++idx) {
id const key = [keys objectAtIndex:idx];
id const obj = [m objectForKey:key];
if (nul == obj) {
[m setObject:empty forKey:key];
}
}
NSDictionary * result = [m copy];
[m release];
return result;
}
The result is the same as, and it appears pretty much identical to Jacob's, but the speed and memory requirements are one half to one third (ARC or MRC) in the tests I made. Of course, you could also use it as a category method as well.
Here is my solution:
+ (NSDictionary *)cleanNullInJsonDic:(NSDictionary *)dic
{
if (!dic || (id)dic == [NSNull null])
{
return dic;
}
NSMutableDictionary *mulDic = [[NSMutableDictionary alloc] init];
for (NSString *key in [dic allKeys])
{
NSObject *obj = dic[key];
if (!obj || obj == [NSNull null])
{
// [mulDic setObject:[#"" JSONValue] forKey:key];
}else if ([obj isKindOfClass:[NSDictionary class]])
{
[mulDic setObject:[self cleanNullInJsonDic:(NSDictionary *)obj] forKey:key];
}else if ([obj isKindOfClass:[NSArray class]])
{
NSArray *array = [BasicObject cleanNullInJsonArray:(NSArray *)obj];
[mulDic setObject:array forKey:key];
}else
{
[mulDic setObject:obj forKey:key];
}
}
return mulDic;
}
+ (NSArray *)cleanNullInJsonArray:(NSArray *)array
{
if (!array || (id)array == [NSNull null])
{
return array;
}
NSMutableArray *mulArray = [[NSMutableArray alloc] init];
for (NSObject *obj in array)
{
if (!obj || obj == [NSNull null])
{
// [mulArray addObject:[#"" JSONValue]];
}else if ([obj isKindOfClass:[NSDictionary class]])
{
NSDictionary *dic = [self cleanNullInJsonDic:(NSDictionary *)obj];
[mulArray addObject:dic];
}else if ([obj isKindOfClass:[NSArray class]])
{
NSArray *a = [BasicObject cleanNullInJsonArray:(NSArray *)obj];
[mulArray addObject:a];
}else
{
[mulArray addObject:obj];
}
}
return mulArray;
}
-(NSDictionary*)stripNulls:(NSDictionary*)dict{
NSMutableDictionary *returnDict = [NSMutableDictionary new];
NSArray *allKeys = [dict allKeys];
NSArray *allValues = [dict allValues];
for (int i=0; i<[allValues count]; i++) {
if([allValues objectAtIndex:i] == (NSString*)[NSNull null]){
[returnDict setValue:#"" forKey:[allKeys objectAtIndex:i]];
}
else
[returnDict setValue:[allValues objectAtIndex:i] forKey:[allKeys objectAtIndex:i]];
}
return returnDict;
}
A category on nsnull that returns nil seems to also sense, at least to me. There are a few out there. One makes all calls return nil which seems to make sense. Sorry no link. I guess if you need to later use nspropertylistserialization the category might not work for you.
I need to merge two NSDictionarys into one provided that if there are dictionaries within the dictionaries, they are also merged.
More or less like jQuery's extend function.
NSDictionary+Merge.h
#import <Foundation/Foundation.h>
#interface NSDictionary (Merge)
+ (NSDictionary *) dictionaryByMerging: (NSDictionary *) dict1 with: (NSDictionary *) dict2;
- (NSDictionary *) dictionaryByMergingWith: (NSDictionary *) dict;
#end
NSDictionary+Merge.m
#import "NSDictionary+Merge.h"
#implementation NSDictionary (Merge)
+ (NSDictionary *) dictionaryByMerging: (NSDictionary *) dict1 with: (NSDictionary *) dict2 {
NSMutableDictionary * result = [NSMutableDictionary dictionaryWithDictionary:dict1];
[dict2 enumerateKeysAndObjectsUsingBlock: ^(id key, id obj, BOOL *stop) {
if (![dict1 objectForKey:key]) {
if ([obj isKindOfClass:[NSDictionary class]]) {
NSDictionary * newVal = [[dict1 objectForKey: key] dictionaryByMergingWith: (NSDictionary *) obj];
[result setObject: newVal forKey: key];
} else {
[result setObject: obj forKey: key];
}
}
}];
return (NSDictionary *) [[result mutableCopy] autorelease];
}
- (NSDictionary *) dictionaryByMergingWith: (NSDictionary *) dict {
return [[self class] dictionaryByMerging: self with: dict];
}
#end
I think this is what you're looking for:
First, you need to make a deep mutable copy, so you can create a category on NSDictionary to do this:
#implementation NSDictionary (DeepCopy)
- (id)deepMutableCopy
{
id copy(id obj) {
id temp = [obj mutableCopy];
if ([temp isKindOfClass:[NSArray class]]) {
for (int i = 0 ; i < [temp count]; i++) {
id copied = [copy([temp objectAtIndex:i]) autorelease];
[temp replaceObjectAtIndex:i withObject:copied];
}
} else if ([temp isKindOfClass:[NSDictionary class]]) {
NSEnumerator *enumerator = [temp keyEnumerator];
NSString *nextKey;
while (nextKey = [enumerator nextObject])
[temp setObject:[copy([temp objectForKey:nextKey]) autorelease]
forKey:nextKey];
}
return temp;
}
return (copy(self));
}
#end
Then, you can call deepMutableCopy like this:
NSMutableDictionary *someDictionary = [someDict deepMutableCopy];
[someDictionary addEntriesFromDictionary:otherDictionary];
I added this to the code mentioned above. It may not be fully correct, but it handles the case where 2 dict has an element that 1 dict does not.
+ (NSDictionary *) dictionaryByMerging: (NSDictionary *) dict1 with: (NSDictionary *) dict2 {
NSMutableDictionary * result = [NSMutableDictionary dictionaryWithDictionary:dict1];
NSMutableDictionary * resultTemp = [NSMutableDictionary dictionaryWithDictionary:dict1];
[resultTemp addEntriesFromDictionary:dict2];
[resultTemp enumerateKeysAndObjectsUsingBlock: ^(id key, id obj, BOOL *stop) {
if ([dict1 objectForKey:key]) {
if ([obj isKindOfClass:[NSDictionary class]]) {
NSDictionary * newVal = [[dict1 objectForKey: key] dictionaryByMergingWith: (NSDictionary *) obj];
[result setObject: newVal forKey: key];
} else {
[result setObject: obj forKey: key];
}
}
else if([dict2 objectForKey:key])
{
if ([obj isKindOfClass:[NSDictionary class]]) {
NSDictionary * newVal = [[dict2 objectForKey: key] dictionaryByMergingWith: (NSDictionary *) obj];
[result setObject: newVal forKey: key];
} else {
[result setObject: obj forKey: key];
}
}
}];
return (NSDictionary *) [[result mutableCopy] autorelease];
}
I came here looking for a copy of jQuery's extend but I ended up writing my own implementation. It's a super simple implementation, I did it so I'd understand a way to do it.
+(NSDictionary*) dictionaryByExtending:(NSDictionary*)baseDictionary WithDictionary:(NSDictionary*)extensionDictionary {
NSMutableDictionary * resultDictionary = [NSMutableDictionary dictionaryWithDictionary:baseDictionary];
[extensionDictionary enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
BOOL isDict = [obj isKindOfClass:[NSDictionary class]];
BOOL hasValue = [baseDictionary hasObjectForKey:key] != nil;
id setObj = obj;
if( hasValue && isDict ) {
BOOL hasDict = [[baseDictionary objectForKey:key] isKindOfClass:[NSDictionary class]];
if( hasDict ) {
NSDictionary * extendedChildDictionary = [NSDictionary dictionaryByExtending:[baseDictionary objectForKey:key] WithDictionary:obj];
setObj = extendedChildDictionary;
}
}
[resultDictionary setObject:setObj forKey:key];
}];
return resultDictionary;
}
-(NSDictionary*) dictionaryByExtendingWithDictionary:(NSDictionary*)extensionDictionary {
return [NSDictionary dictionaryByExtending:self WithDictionary:extensionDictionary];
}
Hopefully someone will find this helpful, it worked in my tests with deep-recursion. I'm using it to extend deep JSON files full of text.
Alexsander Akers works for me except the case where dict2 contains a dictionary that's missing from dict1 - it crashes. I changed the logic to this:
+ (NSDictionary *) dictionaryByMerging: (NSDictionary *) dict1 with: (NSDictionary *) dict2 {
NSMutableDictionary * result = [NSMutableDictionary dictionaryWithDictionary:dict1];
[dict2 enumerateKeysAndObjectsUsingBlock: ^(id key, id obj, BOOL *stop) {
if (![dict1 objectForKey:key]) {
[result setObject: obj forKey: key];
} else if ([obj isKindOfClass:[NSDictionary class]]) {
NSDictionary * newVal = [[dict1 objectForKey: key] dictionaryByMergingWith: (NSDictionary *) obj];
[result setObject: newVal forKey: key];
}
}];
return (NSDictionary *) [result mutableCopy];
}
I know this is an old question, but I need to do the same thing: recursively merge two dictionary objects. I need to go a step further and merge any objects that can be merged recursively (the end goal is merging two dictionaries created from plists). I am hosting my solution at https://github.com/bumboarder6/NSDictionary-merge
I am still working on the project, but as of this writing it already works (in limited testing) for recursive dictionary merging. Arrays and Sets are coming soon.
I noticed a few logic errors in some other solutions I have seen for this problem and I hopefully avoided those pitfalls, but critiques are welcome.
Usage is simple:
#import "NSMutableDictionary-merge.h"
NSMutableDictionary* dict1 = [NSMutableDictionary ...];
NSDictionary* dict2 = [NSDictionary ...];
[dict1 mergeWithDictionary:dict2];
#import "NSDictionary+Merge.h"
#implementation NSDictionary (Merge)
+ (NSDictionary *)dictionaryByMerging:(NSDictionary *)src with:(NSDictionary *)new
{
NSMutableDictionary *result = [src mutableCopy];
[new enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
if ([obj isKindOfClass:[NSDictionary class]]
&& [src[key] isKindOfClass:[NSDictionary class]]) {
result[key] = [src[key] dictionaryByMergingWith:obj];
} else {
result[key] = obj;
}
}];
return [NSDictionary dictionaryWithDictionary:result];
}
- (NSDictionary *)dictionaryByMergingWith:(NSDictionary *)dict {
return [[self class] dictionaryByMerging:self with:dict];
}
#end
I needed a way to recursively merge (append) objects within two JSON objects, focusing on the NSDictionaries within, but also considering NSArrays, and gracefully handling when types don't match along the way. The other answers here didn't go that far, and so I needed to write it myself. The following handles all those cases. Because the validation is at the top rather than in the middle it is usable starting with mixed nonnull and nullable objects. It could be expanded in the future to support additional types where appending may apply. To use, rename the xxx_ prefix to your own three digit prefix in lowercase. This is appropriate since this is an extension to a foundation class:
NSObject+Append.h
#interface NSObject (Append)
+ (nullable id)xxx_objectAppendingObject1:(nullable id)object1 object2:(nullable id)object2 NS_SWIFT_NAME(kva_objectAppending(object1:object2:));
#end
NSObject+Append.m
#implementation NSObject (Append)
+ (nullable id)xxx_objectAppendingObject1:(nullable id)object1 object2:(nullable id)object2
{
// VALIDATE ELSE RETURN
if (object1 == nil)
{
return object2;
}
if (object2 == nil)
{
return object1;
}
// MAIN
// dictionary1
NSDictionary *dictionary1 = [object1 isKindOfClass:NSDictionary.class] ? (NSDictionary *)object1 : nil;
// dictionary2
NSDictionary *dictionary2 = [object2 isKindOfClass:NSDictionary.class] ? (NSDictionary *)object2 : nil;
// array1
NSArray *array1 = [object1 isKindOfClass:NSArray.class] ? (NSArray *)object1 : nil;
// array2
NSArray *array2 = [object2 isKindOfClass:NSArray.class] ? (NSArray *)object2 : nil;
// A. NSDICTIONARY TO NSDICTIONARY
if ((dictionary1 != nil) && (dictionary2 != nil))
{
NSMutableDictionary *returnDictionary = dictionary1.mutableCopy;
[dictionary2 enumerateKeysAndObjectsUsingBlock: ^(id key, id obj, BOOL *stop)
{
returnDictionary[key] = [self.class kva_objectAppendingObject1:dictionary1[key] object2:obj];
}];
return returnDictionary;
}
// B. NSARRAY TO NSARRAY
if ((array1 != nil) && (array2 != nil))
{
return [array1.mutableCopy arrayByAddingObjectsFromArray:array2];
}
// DEFAULT
return object2;
}
#end
With all the URL-handling objects lying around in the standard Cocoa libraries (NSURL, NSMutableURL, NSMutableURLRequest, etc), I know I must be overlooking an easy way to programmatically compose a GET request.
Currently I'm manually appending "?" followed by name value pairs joined by "&", but all of my name and value pairs need to be manually encoded so NSMutableURLRequest doesn't fail entirely when it tries to connect to the URL.
This feels like something I should be able to use a pre-baked API for.... is there anything out of the box to append an NSDictionary of query parameters to an NSURL? Is there another way I should approach this?
Introduced in iOS8 and OS X 10.10 is NSURLQueryItem, which can be used to build queries. From the docs on NSURLQueryItem:
An NSURLQueryItem object represents a single name/value pair for an item in the query portion of a URL. You use query items with the queryItems property of an NSURLComponents object.
To create one use the designated initializer queryItemWithName:value: and then add them to NSURLComponents to generate an NSURL. For example:
NSURLComponents *components = [NSURLComponents componentsWithString:#"http://stackoverflow.com"];
NSURLQueryItem *search = [NSURLQueryItem queryItemWithName:#"q" value:#"ios"];
NSURLQueryItem *count = [NSURLQueryItem queryItemWithName:#"count" value:#"10"];
components.queryItems = #[ search, count ];
NSURL *url = components.URL; // http://stackoverflow.com?q=ios&count=10
Notice that the question mark and ampersand are automatically handled. Creating an NSURL from a dictionary of parameters is as simple as:
NSDictionary *queryDictionary = #{ #"q": #"ios", #"count": #"10" };
NSMutableArray *queryItems = [NSMutableArray array];
for (NSString *key in queryDictionary) {
[queryItems addObject:[NSURLQueryItem queryItemWithName:key value:queryDictionary[key]]];
}
components.queryItems = queryItems;
I've also written a blog post on how to build URLs with NSURLComponents and NSURLQueryItems.
You can create a category for NSDictionary to do this -- there isn't a standard way in the Cocoa library that I could find either. The code that I use looks like this:
// file "NSDictionary+UrlEncoding.h"
#import <cocoa/cocoa.h>
#interface NSDictionary (UrlEncoding)
-(NSString*) urlEncodedString;
#end
with this implementation:
// file "NSDictionary+UrlEncoding.m"
#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
I think the code's pretty straightforward, but I discuss it in some more detail at http://blog.ablepear.com/2008/12/urlencoding-category-for-nsdictionary.html.
I wanted to use Chris's answer, but it wasn't written for Automatic Reference Counting (ARC) so I updated it. I thought I'd paste my solution in case anyone else has this same issue. Note: replace self with the instance or class name where appropriate.
+(NSString*)urlEscapeString:(NSString *)unencodedString
{
CFStringRef originalStringRef = (__bridge_retained CFStringRef)unencodedString;
NSString *s = (__bridge_transfer NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,originalStringRef, NULL, (CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ", kCFStringEncodingUTF8);
CFRelease(originalStringRef);
return s;
}
+(NSString*)addQueryStringToUrlString:(NSString *)urlString withDictionary:(NSDictionary *)dictionary
{
NSMutableString *urlWithQuerystring = [[NSMutableString alloc] initWithString:urlString];
for (id key in dictionary) {
NSString *keyString = [key description];
NSString *valueString = [[dictionary objectForKey:key] description];
if ([urlWithQuerystring rangeOfString:#"?"].location == NSNotFound) {
[urlWithQuerystring appendFormat:#"?%#=%#", [self urlEscapeString:keyString], [self urlEscapeString:valueString]];
} else {
[urlWithQuerystring appendFormat:#"&%#=%#", [self urlEscapeString:keyString], [self urlEscapeString:valueString]];
}
}
return urlWithQuerystring;
}
The other answers work great if the values are strings, however if the values are dictionaries or arrays then this code will handle that.
Its important to note that there is no standard way of passing an array/dictionary via the query string but PHP handles this output just fine
-(NSString *)serializeParams:(NSDictionary *)params {
/*
Convert an NSDictionary to a query string
*/
NSMutableArray* pairs = [NSMutableArray array];
for (NSString* key in [params keyEnumerator]) {
id value = [params objectForKey:key];
if ([value isKindOfClass:[NSDictionary class]]) {
for (NSString *subKey in value) {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)[value objectForKey:subKey],
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#[%#]=%#", key, subKey, escaped_value]];
}
} else if ([value isKindOfClass:[NSArray class]]) {
for (NSString *subValue in value) {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)subValue,
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#[]=%#", key, escaped_value]];
}
} else {
NSString* escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)[params objectForKey:key],
NULL,
(CFStringRef)#"!*'();:#&=+$,/?%#[]",
kCFStringEncodingUTF8);
[pairs addObject:[NSString stringWithFormat:#"%#=%#", key, escaped_value]];
[escaped_value release];
}
}
return [pairs componentsJoinedByString:#"&"];
}
Examples
[foo] => bar
[translations] =>
{
[one] => uno
[two] => dos
[three] => tres
}
foo=bar&translations[one]=uno&translations[two]=dos&translations[three]=tres
[foo] => bar
[translations] =>
{
uno
dos
tres
}
foo=bar&translations[]=uno&translations[]=dos&translations[]=tres
I refactored and converted to ARC answer by AlBeebe
- (NSString *)serializeParams:(NSDictionary *)params {
NSMutableArray *pairs = NSMutableArray.array;
for (NSString *key in params.keyEnumerator) {
id value = params[key];
if ([value isKindOfClass:[NSDictionary class]])
for (NSString *subKey in value)
[pairs addObject:[NSString stringWithFormat:#"%#[%#]=%#", key, subKey, [self escapeValueForURLParameter:[value objectForKey:subKey]]]];
else if ([value isKindOfClass:[NSArray class]])
for (NSString *subValue in value)
[pairs addObject:[NSString stringWithFormat:#"%#[]=%#", key, [self escapeValueForURLParameter:subValue]]];
else
[pairs addObject:[NSString stringWithFormat:#"%#=%#", key, [self escapeValueForURLParameter:value]]];
}
return [pairs componentsJoinedByString:#"&"];
}
- (NSString *)escapeValueForURLParameter:(NSString *)valueToEscape {
return (__bridge_transfer NSString *) CFURLCreateStringByAddingPercentEscapes(NULL, (__bridge CFStringRef) valueToEscape,
NULL, (CFStringRef) #"!*'();:#&=+$,/?%#[]", kCFStringEncodingUTF8);
}
If you are already using AFNetworking (as was the case with me), you can use it's class AFHTTPRequestSerializer to create the required NSURLRequest.
[[AFHTTPRequestSerializer serializer] requestWithMethod:#"GET" URLString:#"YOUR_URL" parameters:#{PARAMS} error:nil];
In case you only require the URL for your work, use NSURLRequest.URL.
Here is a simple example in Swift (iOS8+):
private let kSNStockInfoFetchRequestPath: String = "http://dev.markitondemand.com/Api/v2/Quote/json"
private func SNStockInfoFetchRequestURL(symbol:String) -> NSURL? {
if let components = NSURLComponents(string:kSNStockInfoFetchRequestPath) {
components.queryItems = [NSURLQueryItem(name:"symbol", value:symbol)]
return components.URL
}
return nil
}
I took Joel's recommendation of using URLQueryItems and turned into a Swift Extension (Swift 3)
extension URL
{
/// Creates an NSURL with url-encoded parameters.
init?(string : String, parameters : [String : String])
{
guard var components = URLComponents(string: string) else { return nil }
components.queryItems = parameters.map { return URLQueryItem(name: $0, value: $1) }
guard let url = components.url else { return nil }
// Kinda redundant, but we need to call init.
self.init(string: url.absoluteString)
}
}
(The self.init method is kinda cheesy, but there was no NSURL init with components)
Can be used as
URL(string: "http://www.google.com/", parameters: ["q" : "search me"])
I've got another solution:
http://splinter.com.au/build-a-url-query-string-in-obj-c-from-a-dict
+(NSString*)urlEscape:(NSString *)unencodedString {
NSString *s = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)unencodedString,
NULL,
(CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ",
kCFStringEncodingUTF8);
return [s autorelease]; // Due to the 'create rule' we own the above and must autorelease it
}
// Put a query string onto the end of a url
+(NSString*)addQueryStringToUrl:(NSString *)url params:(NSDictionary *)params {
NSMutableString *urlWithQuerystring = [[[NSMutableString alloc] initWithString:url] autorelease];
// Convert the params into a query string
if (params) {
for(id key in params) {
NSString *sKey = [key description];
NSString *sVal = [[params objectForKey:key] description];
// Do we need to add ?k=v or &k=v ?
if ([urlWithQuerystring rangeOfString:#"?"].location==NSNotFound) {
[urlWithQuerystring appendFormat:#"?%#=%#", [Http urlEscape:sKey], [Http urlEscape:sVal]];
} else {
[urlWithQuerystring appendFormat:#"&%#=%#", [Http urlEscape:sKey], [Http urlEscape:sVal]];
}
}
}
return urlWithQuerystring;
}
You can then use it like so:
NSDictionary *params = #{#"username":#"jim", #"password":#"abc123"};
NSString *urlWithQuerystring = [self addQueryStringToUrl:#"https://myapp.com/login" params:params];
-(NSString*)encodeDictionary:(NSDictionary*)dictionary{
NSMutableString *bodyData = [[NSMutableString alloc]init];
int i = 0;
for (NSString *key in dictionary.allKeys) {
i++;
[bodyData appendFormat:#"%#=",key];
NSString *value = [dictionary valueForKey:key];
NSString *newString = [value stringByReplacingOccurrencesOfString:#" " withString:#"+"];
[bodyData appendString:newString];
if (i < dictionary.allKeys.count) {
[bodyData appendString:#"&"];
}
}
return bodyData;
}
Yet another solution, if you use RestKit there's a function in RKURLEncodedSerialization called RKURLEncodedStringFromDictionaryWithEncoding that does exactly what you want.
Simple way of converting NSDictionary to url query string in Objective-c
Ex: first_name=Steve&middle_name=Gates&last_name=Jobs&address=Palo Alto, California
NSDictionary *sampleDictionary = #{#"first_name" : #"Steve",
#"middle_name" : #"Gates",
#"last_name" : #"Jobs",
#"address" : #"Palo Alto, California"};
NSMutableString *resultString = [NSMutableString string];
for (NSString* key in [sampleDictionary allKeys]){
if ([resultString length]>0)
[resultString appendString:#"&"];
[resultString appendFormat:#"%#=%#", key, [sampleDictionary objectForKey:key]];
}
NSLog(#"QueryString: %#", resultString);
Hope will help :)
If you are already using AFNetwork, you can use their built in serializer to to produce an encoded URL;
NSString *baseURL = #"https://api.app.com/parse";
NSDictionary *mutableParameters = [[NSMutableDictionary alloc] initWithObjectsAndKeys:#"true",#"option1", data, #"option2", token, #"token", #"3.0", #"app", nil];
NSURLRequest *request = [[AFHTTPRequestSerializer serializer] requestWithMethod:#"GET" URLString:baseURL parameters:mutableParameters error:nil];
NSString *urlPath = request.URL.absoluteString;
NSLog(#"%#", urlPath); // https://api.app.com/parse?option1=true&option2=datavalue&token=200%3ATEST%3AENCODE ....
Note; this is an extension to an above answer. The edit queue is full so cannot be added to the existing answer.