翻译强力驱动I have a JSON Feed:
{ "count1" = 2; "count2" = 2; idval = 40; level = ""; "logo_url" = "/assets/logos/default_logo_medium.png"; name = "Golf Club"; "role_in_club" = Admin; } The problem is the " that I cannot figure out how to remove from the NSDictionary before saving it to NSUserDefaults.
Please help me solve this issue. Thankyou!
Iterate through the dictionary and look for any null entries and remove them.
NSMutableDictionary *prunedDictionary = [NSMutableDictionary dictionary]; for (NSString * key in [yourDictionary allKeys]) { if (![[yourDictionary objectForKey:key] isKindOfClass:[NSNull class]]) [prunedDictionary setObject:[yourDictionary objectForKey:key] forKey:key]; }After that, prunedDictionary should have all non-null items in the original dictionary.
Another variation, without (explicit) loop:
NSMutableDictionary *dict = [yourDictionary mutableCopy]; NSArray *keysForNullValues = [dict allKeysForObject:[NSNull null]]; [dict removeObjectsForKeys:keysForNullValues];Use this for remove null from dictionary
- (NSMutableDictionary *)recursive:(NSMutableDictionary *)dictionary { for (NSString *key in [dictionary allKeys]) { id nullString = [dictionary objectForKey:key]; if ([nullString isKindOfClass:[NSDictionary class]]) { [self recursive:(NSMutableDictionary*)nullString]; } else { if ((NSString*)nullString == (id)[NSNull null]) [dictionary setValue:@"" forKey:key]; } } return dictionary; }Here is my category-based recursive solution for dictionaries containing dictionaries and arrays which values can also be dictionaries and arrays:
File NSDictionary+Dario.m:
#import "NSArray+Dario.h" @implementation NSDictionary (Dario) - (NSDictionary *) dictionaryByReplacingNullsWithEmptyStrings { const NSMutableDictionary *replaced = [NSMutableDictionary new]; const id nul = [NSNull null]; const NSString *blank = @""; for(NSString *key in self) { const id object = [self objectForKey:key]; if(object == nul) { [replaced setObject:blank forKey:key]; } else if ([object isKindOfClass:[NSDictionary class]]) { [replaced setObject:[object dictionaryByReplacingNullsWithEmptyStrings] forKey:key]; } else if ([object isKindOfClass:[NSArray class]]) { [replaced setObject:[object arrayByReplacingNullsWithEmptyStrings] forKey:key]; } else { [replaced setObject:object forKey:key]; } } return [NSDictionary dictionaryWithDictionary:(NSDictionary*)replaced]; } @endFile NSArray+Dario.m:
#import "NSDictionary+Dario.h" @implementation NSArray (Dario) - (NSArray *) arrayByReplacingNullsWithEmptyStrings { const NSMutableArray *replaced = [NSMutableArray new]; const id nul = [NSNull null]; const NSString *blank = @""; for (int i=0; iTo remove it, convert it into a mutable dictionary and remove the object for key "level";
NSDictionary* dict = ....; // this is the dictionary to modify NSMutableDictionary* mutableDict = [dict mutableCopy]; [mutableDict removeObjectForKey:@"level"]; dict = [mutableDict copy];If you don't use ARC, you'll need to add some calls to 'release'.
Update:
If you don't know the name of the key(s) with the " objects, then you have to iterate:
NSDictionary* dict = ....; // this is the dictionary to modify NSMutableDictionary* mutableDict = [dict mutableCopy]; for (id key in dict) { id value = [dict objectForKey: key]; if ([@"" isEqual: value]) { [mutableDict removeObjectForKey:key]; } } dict = [mutableDict copy]; To locate the " values, I'm using a string comparison since " is a string in your sample. But I'm not sure if this is really the case.
I belive this is the most resource saving way
// category implementation on NSDictionary
- (NSDictionary *)dictionaryByRemovingNullValues { NSMutableDictionary * d; for (NSString * key in self) { if (self[key] == [NSNull null]) { if (d == nil) { d = [NSMutableDictionary dictionaryWithDictionary:self]; } [d removeObjectForKey:key]; } } if (d == nil) { return self; } return d; }I have created a category for NSJSOn serialisation class.
Create a category and import class to use its methods...
// Mutable containers are required to remove nulls. if (replacingNulls) { // Force add NSJSONReadingMutableContainers since the null removal depends on it. opt = opt || NSJSONReadingMutableContainers; } id JSONObject = [self JSONObjectWithData:data options:opt error:error]; if ((error && *error) || !replacingNulls) { return JSONObject; } [JSONObject recursivelyReplaceNullsIgnoringArrays:ignoreArrays withString:replaceString]; return JSONObject;I tried the solution for your question and i got it
NSDictionary *dict = [[NSDictionary alloc]initWithObjectsAndKeys:@"2",@"count1",@"2",@"count2",@"40",@"idval",@"",@"level",@"/assets/logos/default_logo_medium.png",@"logo_url",@"Golf Club",@"name",@"role_in_club",@"Admin", nil]; NSMutableDictionary *mutableDict = [dict mutableCopy]; for (NSString *key in [dict allKeys]) { if ([dict[key] isEqual:[NSNull null]]) { mutableDict[key] = @""; } if([dict[key] isEqualToString:@""]) { mutableDict[key] = @""; } } dict = [mutableDict copy]; NSLog(@"The dict is - %@",dict); Finally the answer is
The dict is - { Admin = "role_in_club"; count1 = 2; count2 = 2; idval = 40; level = ""; "logo_url" = "/assets/logos/default_logo_medium.png"; name = "Golf Club"; }I am doing in this way.
NSMutableDictionary *prunedDict = [NSMutableDictionary dictionary]; [self enumerateKeysAndObjectsUsingBlock:^(NSString *key, id obj, BOOL *stop) { if (![obj isKindOfClass:[NSNull class]]) { prunedDict[key] = obj; } }];the following code is ok when the result is in array or dictionary , you can change the result returned to nil or empty string by editing the code
the function is recursive , so can parse array in dictionary .
-(id)changeNull:(id)sender{ id newObj; if ([sender isKindOfClass:[NSArray class]]){ NSMutableArray *newArray = [[NSMutableArray alloc] init]; for (id item in sender){ [newArray addObject:[self changeNull:item]]; } newObj = newArray; } else if ([sender isKindOfClass:[NSDictionary class]]){ NSMutableDictionary *newDict = [[NSMutableDictionary alloc] init]; for (NSString *key in sender){ NSDictionary *oldDict = (NSDictionary*)sender; id item = oldDict[key]; if (![item isKindOfClass:[NSDictionary class]] && ![item isKindOfClass:[NSArray class]]){ if ([item isEqual:[NSNull null]]){ item = @""; } [newDict setValue:item forKey:key]; } else{ [newDict setValue:[self changeNull:item] forKey:key]; } } newObj = newDict; } return newObj; }jsonresult ( { Description = ""; Id = 1; Name = High; }, { Description = ""; Id = 2; Name = Medium; }, { Description = ""; Id = 3; Name = Low; } )
change null ( { Description = ""; Id = 1; Name = High; }, { Description = ""; Id = 2; Name = Medium; }, { Description = ""; Id = 3; Name = Low; } )
Swift 3.0/4.0 Solution
Following is the solution, when JSON have sub-dictionaries. This will go-through all the dictionaries, sub-dictionaries of JSON and remove NULL(NSNull) key-value pair from the JSON.
extension Dictionary { func removeNull() -> Dictionary { let mainDict = NSMutableDictionary.init(dictionary: self) for _dict in mainDict { if _dict.value is NSNull { mainDict.removeObject(forKey: _dict.key) } if _dict.value is NSDictionary { let test1 = (_dict.value as! NSDictionary).filter({ $0.value is NSNull }).map({ $0 }) let mutableDict = NSMutableDictionary.init(dictionary: _dict.value as! NSDictionary) for test in test1 { mutableDict.removeObject(forKey: test.key) } mainDict.removeObject(forKey: _dict.key) mainDict.setValue(mutableDict, forKey: _dict.key as? String ?? "") } if _dict.value is NSArray { let mutableArray = NSMutableArray.init(object: _dict.value) for (index,element) in mutableArray.enumerated() where element is NSDictionary { let test1 = (element as! NSDictionary).filter({ $0.value is NSNull }).map({ $0 }) let mutableDict = NSMutableDictionary.init(dictionary: element as! NSDictionary) for test in test1 { mutableDict.removeObject(forKey: test.key) } mutableArray.replaceObject(at: index, with: mutableDict) } mainDict.removeObject(forKey: _dict.key) mainDict.setValue(mutableArray, forKey: _dict.key as? String ?? "") } } return mainDict as! Dictionary } }