I have a certain NSDictionary with couple of keys but they go much in dept in hirerchy such as:
Person:
Gender:
Name:
Address:
Location:
So you can see if I insert this in nsdictionary, initially I just have two keys as "Person" and "Location", however I am trying to iterate in each one of the keys to check for null value and set it to #"" empty string.
Does anyone know how to iterate through such dept?
Thanks
you can't store a nil in an NSDictionary. Either you'll be looking for [NSNull null] or you'll be looking for dictionaries that lack the keys you are looking for....
enumerateKeysAndObjectsUsingBlock: is faster than for( ... in ...).
if you are modifying the contents of the dictionaries, you must use mutable dictionaries. If you are unarchiving from a property list, there are options for creating mutable containers with immutable nodes (which is probably what you want).
Recurse is the answer, though non of the answers that show recursion are correct.
- (void)filterMutableDictionary:(NSMutableDictionary*)aDictionary
{
// check if aDictionary is missing any keys here
if (![aDictionary objectForKey:#"DesiredKey"]) {
... fill in key/value here ...
}
// enumerate key/values, filtering appropriately, recursing as necessary
[aDictionary enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop) {
if ([value isKindOfClass: [NSMutableDictionary class]]) {
[self filterMutableDictionary: value];
} else {
... filter value here ...
}
}];
}
In the simplest form:
[dictionary enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
if ([obj isKindOfClass:[NSNull class]]) [dictionary setValue:[NSString stringWithString:#""] forKey:key];
} ];
You could use a recursive method, like this:
- (void)recursive:(NSDictionary*)aDictionary {
for (id key in aDictionary) {
id value = [aDictionary objectForKey:key];
if ([value isKindOfClass:[NSDictionary class]]) {
[self recursive:value];
} else {
// Do something else, the value is not a dictionary
}
}
}
Inside your loop as you are checking for values use this for checking against null.
if ([[dict objectForKey:#"Gender"] isKindOfClass:[NSNull class]]) {
// null value
myGender = #"";
}
- (void)recursive:(NSDictionary)dictionary {
for (NSString *key in [dictionary allKeys]) {
id nullString = [dictionary objectForKey:key];
if ([nullString isKindOfClass:[NSDictionary class]]) {
[self recursive:(NSDictionary*)nullString];
} else {
if ( (NSString*)nullString == nil)
[dictionary setObject:#"" forKey:#"key"];
}
}
}
Related
I have a code like that
if ([dataArray valueForKey:#"success"]) {
[self.feedsArray addObjectsFromArray:dataArray];
NSLog(#"self.feedsArray: %#",self.feedsArray);
} else {
NSLog(#"no feed found ");
}
dataArray is a NSMutableArray which ultimately contains a JSON Dictionary.
but I am getting the same console output independent of success either TRUE or FALSE, but my console output is always same.my console output is:
for FALSE or NO:
self.feedsArray: (
{
action = register;
message = "Invalid parameters";
success = 0;
}
)
and for TRUE or YES:
self.feedsArray: (
{
action = register;
message = "valid parameters";
success = 1;
}
)
in both cases if part is executed.
in NSUserDefaults there is a method boolForKey but how to do this in case of NSMutableArray.
You need to read the fine print for [NSArray valueForKey:], specifically:
Returns an array containing the results of invoking valueForKey: using
key on each of the array's objects.
and:
The returned array contains NSNull elements for each object that
returns nil.
So if the array contains, say, 3 objects and none of them have a success key then you will get an array of 3 NSNull objects returned.
Therefore the if statement will fire whenever dataArray is non-empty, which is obviously not what you intended.
You should check the contents of the returned array:
BOOL succeeded = NO;
NSArray *results = [dataArray valueForKey:#"success"];
for (NSObject *obj in results) {
succeeded = [obj isKindOfClass:[NSNumber class]] && [(NSNumber *)obj boolValue];
if (succeeded)
break;
}
if (succeeded) {
[self.feedsArray addObjectsFromArray:dataArray];
NSLog(#"self.feedsArray: %#",self.feedsArray);
} else {
NSLog(#"no feed found ");
}
You can do this in simple way:
What i see in your response json value is, you have dictionary in dataArray at index 0
NSMutableDictionary *responseDict = [dataArray objectAtIndex:0];
if([[responseDict objectForKey:#"success"] boolValue])
{
NSLog(#"Success: 1");
}
{
NSLog(#"Success: 0");
}
Use index instead of key for an array.
NSDictionary dictionary = (NSDictionary *)dataArray[0];
if ([(NSNumber *)[dictionary objectForKey:#"success"] boolValue]) {
// ...
}
otherwise use if([[[dataArray objectAtIndex:0] valueForKey:#"success"] isEqualToString:#"1"])
An array does not store keys, the only way to access items in an array is by index.
You should be using an NSDictionary/NSMutableDictionary instead. If you want to use a bool store it as a NSNumber, [NSNumber numberWithBool:YES] and then use the instance method valueForBool to read it back.
Try this
if ([[dataArray valueForKey:#"success"]isEqualToString:#"1"]) {
[self.feedsArray addObjectsFromArray:dataArray];
NSLog(#"self.feedsArray: %#",self.feedsArray);
}
else {
NSLog(#"no feed found ");
}
It 'll work out.
use this if you want bool value
if([[dataArray valueForKey:#"success"] boolValue])
{
//i.e success is true
}
if response contains array of dictionaries then we can use loop and check condition,
here i is index variable of array,
if([[[dataArray objectAtIndex:i] objectForKey:#"success"] boolValue])
{
// success is true ,
}
Replace you code line
if ([dataArray valueForKey:#"success"]) {
}
with
if ([[dataArray valueForKey:#"success"] integerValue]) {
}
Hope it will work for you.
its working with replacing the line with
if ([[[dataArray objectAtIndex:0] valueForKey:#"success"] boolValue])
Currently I am using the following method to validate the data for not being Null.
if ([[response objectForKey:#"field"] class] != [NSNull class])
NSString *temp = [response objectForKey:#"field"];
else
NSString *temp = #"";
Problem comes when the response Dictionary contains hundreds of attributes (and respective values). I need to add this kind of condition to each and every element for the dictionary.
Any other way around to accomplish?
Any Suggestion for making any change to the web service (except not inserting the null value to database)?
Any Idea, Anyone ??
What I've done is put a category on NSDictionary
#interface NSDictionary (CategoryName)
/**
* Returns the object for the given key, if it is in the dictionary, else nil.
* This is useful when using SBJSON, as that will return [NSNull null] if the value was 'null' in the parsed JSON.
* #param The key to use
* #return The object or, if the object was not set in the dictionary or was NSNull, nil
*/
- (id)objectOrNilForKey:(id)aKey;
#end
#implementation NSDictionary (CategoryName)
- (id)objectOrNilForKey:(id)aKey {
id object = [self objectForKey:aKey];
return [object isEqual:[NSNull null]] ? nil : object;
}
#end
Then you can just use
[response objectOrNilForKey:#"field"];
You can modify this to return a blank string if you'd like.
First a minor point: your test is not idiomatic, you should use
if (![[response objectForKey:#"field"] isEqual: [NSNull null]])
If you want all keys in your dictionary that have a value of [NSNull null] to be reset to the empty string, the easiest way to fix it is
for (id key in [response allKeysForObject: [NSNull null]])
{
[response setObject: #"" forKey: key];
}
The above assumes response is a mutable dictionary.
However, I think you really need to review your design. You shouldn't be allowing [NSNull null] values at all if they are not allowed in the database.
It's not quite clear for me what you need but:
If you need to check whether the value for key is not NULL you can do this:
for(NSString* key in dict) {
if( ![dict valueForKey: key] ) {
[dict setValue: #"" forKey: key];
}
}
If you have some set of required keys, you can create static array and then do this:
static NSArray* req_keys = [[NSArray alloc] initWithObjects: #"k1", #"k2", #"k3", #"k4", nil];
Then in the method where you check your data:
NSMutableSet* s = [NSMutableSet setWithArray: req_keys];
NSSet* s2 = [NSSet setWithArray: [d allKeys]];
[s minusSet: s2];
if( s.count ) {
NSString* err_str = #"Error. These fields are empty: ";
for(NSString* field in s) {
err_str = [err_str stringByAppendingFormat: #"%# ", field];
}
NSLog(#"%#", err_str);
}
static inline NSDictionary* DictionaryRemovingNulls(NSDictionary *aDictionary) {
NSMutableDictionary *returnValue = [[NSMutableDictionary alloc] initWithDictionary:aDictionary];
for (id key in [aDictionary allKeysForObject: [NSNull null]]) {
[returnValue setObject: #"" forKey: key];
}
return returnValue;
}
response = DictionaryRemovingNulls(response);
I've already asked a similar question but this is slightly different so i Thought it would be fine to ask another question.
I'm storing Arrays within Arrays, as well as NSDictionaries. It's a utility kind of application and there is no set structure, the user can enter nested information as much as they require.
I need a method that can scroll through the entire contents of an Array/Dictionary and return the specific dictionary based on a value that I send the method. Here's an example..
NSMutableArray *array = [[NSMutableArray alloc]init];
NSMutableDictionary *enteredItem = [[NSMutableDictionary alloc]init];
[enteredItem setObject:#"i'm a title" forKey:#"title"];
[enteredItem setObject:#"i'm an id" forKey:#"id"];
[enteredItem setObject:#"i'm a description" forKey:#"description"];
[enteredItem setObject:#"i'm a timestamp" forKey:#"timestamp"];
[enteredItem setObject:array forKey:#"items"];
[array addObject:enteredItem];
[array addObject:anotherDictionary];
[array addObject:moreDictionaries];
So in the example above, I would need to find (return) the dictionary that contains "i'm an id".
The similar question I asked is located here.. Searching for a value in an unknown NSMutableArray depth - I'm having trouble returning a dictionary and also comparing the object.
Hopefully my question is clear. Thanks for any help you can offer.
Continuing from the answer, you need to do some modification:
- (id)findDictionaryWithValue:(id)value inArray:(NSArray *)array
{
__block id match = nil;
[array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
if ([obj isKindOfClass:[NSArray class])
{
match = [self findDictionaryWithValue:value inArray:obj];
}
else if ([obj isKindOfClass:[NSDictionary class])
{
match = [self findDictionaryWithValue:value inDictionary:obj];
}
*stop = (match!=nil);
}];
return match;
}
- (id)findDictionaryWithValue:(id)value inDictionary:(NSDictionary *)dict;
{
__block id match = nil;
[dict enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
if([obj isEqual:value]) {
match = dict;
}
else if ([obj isKindOfClass:[NSArray class])
{
match = [self findDictionaryWithValue:value inArray:obj];
}
else if ([obj isKindOfClass:[NSDictionary class])
{
match = [self findDictionaryWithValue:value inDictionary:obj];
}
*stop = (match!=nil);
}];
return match;
}
NSDictionary *resultDict = [self findDictionaryForValue:#"i'm an id" inArray:array];
However, you must be careful with recursion. If there is any circular path, you will get an infinite loop( and stack overflow before crash).
Now I'm trying the following and it works.
- (void)findDictionaryWithValueForKey:(NSString *)name {
for (NSDictionary * set in myArray) {
if ([[set objectForKey:#"title"] isEqualToString:name])
\\do something
}
}
EDIT:
I've added one extra argument to the post of bshirley. Now it looks more flexible.
- (NSDictionary *)findDictionaryWithValue:(NSString*)name forKey:(NSString *)key {
__block BOOL found = NO;
__block NSDictionary *dict = nil;
[self.cardSetsArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
dict = (NSDictionary *)obj;
NSString *title = [dict valueForKey:key];
if ([title isEqualToString:name]) {
found = YES;
*stop = YES;
}
}];
if (found) {
return dict;
} else {
return nil;
}
}
Here's one possible implementation using newer API. (I also modified the method to actually return the value). Provided mostly to demonstrate that API. The assumption is that the title is unique to one dictionary within your array.
- (NSDictionary *)findDictionaryWithValueForKey:(NSString *)name {
// ivar: NSArray *myArray;
__block BOOL found = NO;
__block NSDictionary *dict = nil;
[myArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
dict = (NSDictionary *)obj;
NSString *title = [dict valueForKey:#"title"];
if ([title isEqualToString:name]) {
found = YES;
*stop = YES;
}
}];
if (found) {
return dict;
} else {
return nil;
}
}
Use filteredArrayUsingPredicate: method of the array to get all the dictionaries that satisfy your requirement.
NSPredicate * predicate = [NSPredicate predicateWithFormat:#" title MATCHES[cd] %#", name];
NSArray * matches = [myArray filteredArrayUsingPredicate:predicate];
Now matches is the array of dictionaries that have the title key equal to name.
- (void)findDictionaryWithValueForKey:(NSString)name {
for (NSDictionary * set in myArray) {
NSString *s=[NSString stringWithFormat:#"%#",[set objectForKey:#"title"]];
if ([s isEqualToString:name])
\\do something
}
OR
if (s == name])
\\do something
}
}
I will also suggest this way,it would be better if you use a break statement,
- (void)findDictionaryWithValueForKey:(NSString)name {
for (NSDictionary * set in myArray) {
if ([[set objectForKey:#"title"] isEqualToString:name])
\\do something
break;
}
}
As per the NSArray documentation,
valueForKey:
Returns an array containing the results of invoking valueForKey: using key on each of the array's objects.
- (id)valueForKey:(NSString *)key
Parameters
key
The key to retrieve.
Return Value
The value of the retrieved key.
Discussion
The returned array contains NSNull elements for each object that returns nil.
Availability
* Available in Mac OS X v10.3 and later.
EDIT:
try this,
[myArray valueForKey:#"name"];
//this will return array of values, but this actually differ from what to want
I am having a NSMutableDictionary. I have to dynamically rename any Key in the dictionary to a new value, in my code.. I can't find any built-in API to do this..
How can I do this? Is there any built-in API available to do this?
Thanks everyone..
// assumes that olkdey and newkey won't be the same; they can't as
// constants... but...
[dict setObject: [dict objectForKey: #"oldkey"] forKey: #"newkey"];
[dict removeObjectForKey: #"oldkey"];
Think about what "directly editing an existing key" means. A dictionary is a hash; it hashes the contents of the keys to find a value.
What happens if you were to change the contents of a key? The key would need to be rehashed (and the dictionary's internal structures re-balanced) or the value would no longer be retrievable.
Why do you want to edit the contents of a key in the first place? I.e. what problem does that solve that the above does not?
This should work:
- (void) renameKey:(id<NSCopying>)oldKey toKey:(id<NSCopying>)newKey{
NSObject *object = [dictionary objectForKey:oldKey];
[object retain];
[dictionary removeObjectForKey:oldKey];
[dictionary setObject:object forKey:newKey];
[object release];
}
This does exactly the same as bbum's answer but, if you remove the old key first (like in this example) then you have to retain the object temporarily otherwise it might get deallocated in the way ;)
Conclusion: Unless you need explicitly to remove the old key first do as bbum.
#interface NSMutableDictionary (KAKeyRenaming)
- (void)ka_replaceKey:(id)oldKey withKey:(id)newKey;
#end
#implementation NSMutableDictionary (KAKeyRenaming)
- (void)ka_replaceKey:(id)oldKey withKey:(id)newKey
{
id value = [self objectForKey:oldKey];
if (value) {
[self setObject:value forKey:newKey];
[self removeObjectForKey:oldKey];
}
}
#end
This also handles the case where the dictionary doesn't have a value for the key nicely.
I have to navigate a complete JSON response object that holds fields, sub-dictionaries and sub-arrays. All because one of the JSON fields is called "return" which is an iOS reserved word, so can't be used with the JSONModel Cocoa Pod.
Here's the code:
+ (id) sanitizeJSON:(id) dictIn {
if (dictIn) //check not null
{
// if it's a dictionary item
if ([dictIn isKindOfClass:[NSDictionary class]])
{
NSMutableDictionary *dictOut = [dictIn mutableCopy];
// Do the fix replace "return" with "not_return"
if ([dictOut objectForKey: #"return"])
{[dictOut setObject: [dictIn objectForKey: #"return"] forKey: #"not_return"];
[dictOut removeObjectForKey: #"return"];}
// Continue the recursive walk through
NSArray*keys=[dictOut allKeys]; //get all the keys
for (int n=0;n<keys.count;n++)
{
NSString *key = [keys objectAtIndex:n];
//NSLog(#"key=%# value=%#", key, [dictOut objectForKey:key]);
if (([[dictOut objectForKey:key] isKindOfClass:[NSDictionary class]]) || ([[dictOut objectForKey:key] isKindOfClass:[NSArray class]]))
{
// recursive call
id sanitizedObject = [self sanitizeJSON:[dictOut objectForKey:key]];
[dictOut removeObjectForKey: key];
[dictOut setObject:sanitizedObject forKey:key];
// replace returned (poss modified) item with this one
}
}
return dictOut; //return dict
}
else if ([dictIn isKindOfClass:[NSArray class]]) //Or if it's an array item
{
NSMutableArray *tempArray = [dictIn mutableCopy];
// Do the recursive walk across the array
for (int n=0;n< tempArray.count; n++)
{
// if array item is dictionary
if (([[tempArray objectAtIndex:n] isKindOfClass:[NSDictionary class]]) || ([[tempArray objectAtIndex:n] isKindOfClass:[NSArray class]]))
{
// recursive call
id sanitizedObject = [self sanitizeJSON:[tempArray objectAtIndex:n]];
// replace with the possibly modified item
[tempArray replaceObjectAtIndex:n withObject:sanitizedObject];
}
}
return tempArray; //return array
}
return dictIn; //Not nil or dict or array
}
else
return dictIn; //return nil
}