I am trying to create a dictionary (Not sure whether it should be NSDictionary or NSMutableDictionary) from NSString to an array (Not sure whether it should be NSArray or NSMutableArray).
property:
#property(nonatomic, readonly) NSMutableDictionary * categories;
implementation:
#synthesize categories = _categories;
- (NSMutableDictionary *)categories{
if(! _categories) {
for(PFObject * each in self.products) {
NSString * currentcategory = [each valueForKey:#"subtitle"];
NSArray * currentlist = [_categories objectForKey:currentcategory];
if(! currentlist) {
currentlist = [[NSArray alloc] init];
}
NSMutableArray * newArray = [currentlist mutableCopy];
[newArray addObject:each];
NSArray * newlist = [NSArray arrayWithArray:newArray];
[_categories setObject:newlist forKey:currentcategory];
}
}
NSLog(#"After constructor the value of the dictionary is %d", [_categories count]);
return _categories;
}
From the debug NSLog I realize that the dictionary is empty after the construction. What is wrong here and how shall I change it?
After code line
if(! _categories) {
add
_categories = [NSMutableDictionary new];
If you did not initialize _category array somewhere in code then.
you must instantiate it inside
if(!_categories)
Your NSMutableArray _categories instance is not allocated and initialized yet.
To create instance of NSMutableArray just add
_categories = [NSMutableArray arrayWithCapacity:0];
Related
I have an NSMutableArray that contains several NSMutableDictionary object, each dict has a NSString and an NSMutableArray in it.
My problem is that I need to find the correct dict based on a string match and when found insert an object into the NSMutableArray in the same dict where the string match was found, I can only make this work the first time when the array is empty because after that I am unable to match the correct string:
Here is what I have tried so far, I tried using contains object but that wont get me inside the dict inside the array so I am stuck
NSMutableArray *variantOptions = [[NSMutableArray alloc] init];
for (NSDictionary *variant in variantInfo) {
NSMutableDictionary *variantOption = [[NSMutableDictionary alloc] init];
NSMutableArray *variantOptionValues = [[NSMutableArray alloc] init];
NSString *name = variant[#"name"];
NSString *value = variant[#"value"];
if(variantOptions.count > 0) {
// Need to loop through the array until name isEquaToString variantOptionName and when true insert value into variantOptionValuesArray in that same dict and if not exists create a new dict and insert in array
} else {
[variantOptionValues addObject:value];
[variantOption setObject:name forKey:#"variantOptionName"];
[variantOption setObject:variantOptionValues forKey:#"variantOptionValues"];
}
[variantOptions addObject:variantOption];
}
for (NSDictionary *variant in variantInfo) {
NSString *name = variant[#"name"];
NSString *value = variant[#"value"];
BOOL found = false;
for (NSMutableDictionary *v in variantOptions) {
if (v[#"name"] isequalToString:name]) {
NSMutableArray *values = v[#"variantOptionValues"];
[values addObject:value];
found = true;
break;
}
}
if (!found) {
// name was not found
NSMutableDictionary *variantOption = [[NSMutableDictionary alloc] init];
NSMutableArray *variantOptionValues = [NSMutableArray alloc] init];
[variantOptionValues addObject:value];
[variantOption setObject:name forKey:#"variantOptionName"];
[variantOption setObject:variantOptionValues forKey:#"variantOptionValues"];
[variantOptions addObject:variantOption];
}
}
I'm having difficulty figuring out how to incorporate a counter so the "setObject" increments it's 'Save' in this for..loop.
NSMutableArray *NewArray = [NSMutableArray new];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for ( DBFILESMetadata *entry in result.entries) {
[dict setObject:entry.pathDisplay forKey:#"pathDisplay"];
[dict setObject:entry.name forKey:#"name"];
[NewArray addObject:dict];
}
I'm sure this is an easy answer,the last line is only saving the last item of result.entries. The NewArray has the correct count of items, but every item in the array is the last item of result.entries:
2017-04-13 16:47:58.876 Sites[11145:688352] NewArray (
{
name = 229;
pathDisplay = "/Sites/229";
},
{
name = 229;
pathDisplay = "/Sites/229";
}
).
I need to add a counter of some type to set the next object, just confused on where it should go.
Thanks in advance.
I figured this out:
for ( DBFILESMetadata *entry in result.entries) {
[imagePaths addObject:entry.pathDisplay];
[names addObject:entry.name];
}
for(int i=0; i<[result.entries count]; i++) {
dict = #{#"name": names[i], #"pathDisplay": imagePaths[i]};
[allObjects addObject:dict];
}
The dictionary item keys must be different. Otherwise, you see always last set item. Because the dictionary will overide when the save same key. So you can use just like below.
1.Solutions
NSMutableArray *NewArray = [NSMutableArray new];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
int i = 0;
for ( DBFILESMetadata *entry in result.entries) {
[dict setObject:entry.pathDisplay forKey:[NSString stringWithFormat:#"pathDisplay%d",i]];
[dict setObject:entry.name forKey:[NSString stringWithFormat:#"name%d",i]];
[NewArray addObject:dict];
i++;
}
2.Solution
Create a class that will hold the json property, just like a below.
HoldJsonDataClass.h
#interface HoldJsonDataClass : JsonData
#property (nonatomic,retain) NSString *name;
#property (nonatomic,retain) NSString * pathDisplay;
#end
HoldJsonDataClass.m
#implementation HoldJsonDataClass
#end
And than fill the class to the array. This solution is more clear.
for ( DBFILESMetadata *entry in result.entries) {
HoldJsonDataClass *holdJsonClass = [HoldJsonDataClass new];
holdJsonClass.name = entry.name;
holdJsonClass.pathDisplay = entry.pathDisplay;
[NewArray addObject:holdJsonClass];
}
I have a horizontally and vertically scrollable table. I get the data for the header and first column from the web service(json). I want to sort the data in ascending order and remove duplicate data from both header and the first column. For removing duplicate values I used the following code:
-(void) requestFinished: (ASIHTTPRequest *) request
{
NSString *theJSON = [request responseString];
SBJsonParser *parser = [[SBJsonParser alloc] init];
NSMutableArray *jsonDictionary = [parser objectWithString:theJSON error:nil];
headData = [[NSMutableArray alloc] init];
NSMutableArray *head = [[NSMutableArray alloc] init];
leftTableData = [[NSMutableArray alloc] init];
NSMutableArray *left = [[NSMutableArray alloc] init];
rightTableData = [[NSMutableArray alloc]init];
for (NSMutableArray *dictionary in jsonDictionary)
{
Model *model = [[Model alloc]init];
model.cid = [[dictionary valueForKey:#"cid"]intValue];
model.iid = [[dictionary valueForKey:#"iid"]intValue];
model.yr = [[dictionary valueForKey:#"yr"]intValue];
model.val = [dictionary valueForKey:#"val"];
[mainTableData addObject:model];
[head addObject:[NSString stringWithFormat:#"%ld", model.yr]];
[left addObject:[NSString stringWithFormat:#"%ld", model.iid]];
}
NSOrderedSet *orderedSet = [NSOrderedSet orderedSetWithArray:head];
headData = [[orderedSet array] mutableCopy];
// NSSet *set = [NSSet setWithArray:left];
// NSArray *array2 = [set allObjects];
// NSLog(#"%#", array2);
NSOrderedSet *orderedSet1 = [NSOrderedSet orderedSetWithArray:left];
NSMutableArray *arrLeft = [[orderedSet1 array] mutableCopy];
//remove duplicate enteries from header array
[leftTableData addObject:arrLeft];
NSMutableArray *right = [[NSMutableArray alloc]init];
for (int i = 0; i < arrLeft.count; i++)
{
NSMutableArray *array = [[NSMutableArray alloc] init];
for (int j = 0; j < headData.count; j++)
{
/* NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF.iid == %ld", [[arrLeft objectAtIndex:i] intValue]];
NSArray *filteredArray = [mainTableData filteredArrayUsingPredicate:predicate];*/
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF.iid == %ld AND SELF.yr == %ld", [[arrLeft objectAtIndex:i] intValue], [[headData objectAtIndex:j] intValue]];
NSArray *filteredArray = [mainTableData filteredArrayUsingPredicate:predicate];
if([filteredArray count]>0)
{
Model *model = [filteredArray objectAtIndex:0];
[array addObject:model.val];
}
}
[right addObject:array];
}
[rightTableData addObject:right];
}
How will I sort the arrays in ascending order?
Please help.
OK, so you have a model object that looks something like this...
#interface Model: NSObject
#property NSNumber *idNumber;
#property NSNumber *year;
#property NSString *value;
#end
Note, I am intentionally using NSNumber and not NSInteger for reasons that will become clear.
At the moment you are trying to do a lot all in one place. Don't do this.
Create a new object to store this data. You can then add methods to get the data you need. Seeing as you are displaying in a table view sectioned by year and then each section ordered by idNumber then I'd do something like this...
#interface ObjectStore: NSObject
- (void)addModelObject:(Model *)model;
// standard table information
- (NSInteger)numberOfYears;
- (NSInteger)numberOfIdsForSection:(NSinteger)section;
// convenience methods
- (NSNumber *)yearForSection:(NSInteger)section;
- (NSNumber *)idNumberForSection:(NSInteger)section row:(NSInteger)row;
- (NSArray *)modelsForSection:(NSInteger)section row:(NSInteger)row;
// now you need a way to add objects
- (void)addModelObject:(Model *)model;
#end
Now to implement it.
We are going to store everything in one dictionary. The keys will be years and the objects will be dictionaries. In these dictionaries the keys will be idNumbers and the objects will be arrays. These array will hold the models.
So like this...
{
2010 : {
1 : [a, b, c],
3 : [c, d, e]
},
2013 : {
1 : [g, h, u],
2 : [e, j, s]
}
}
We'll do this with all the convenience methods also.
#interface ObjectStore: NSObject
#property NSMutableDictionary *objectDictionary;
#end
#implementation ObjectStore
+ (instancetype)init
{
self = [super init];
if (self) {
self.objectDictionary = [NSMutableDictionary dictionary];
}
return self;
}
+ (NSInteger)numberOfYears
{
return self.objectDictionary.count;
}
+ (NSInteger)numberOfIdsForSection:(NSinteger)section
{
// we need to get the year for this section in order of the years.
// lets create a method to do that for us.
NSNumber *year = [self yearForSection:section];
NSDictionary *idsForYear = self.objectDictionary[year];
return idsForYear.count;
}
- (NSNumber *)yearForSection:(NSInteger)section
{
// get all the years and sort them in order
NSArray *years = [[self.obejctDictionary allKeys] sortedArrayUsingSelector:#selector(compare:)];
// return the correct year
return years[section];
}
- (NSNumber *)idNumberForSection:(NSInteger)section row:(NSInteger)row
{
// same as the year function but for id
NSNumber *year = [self yearForSection:section];
NSArray *idNumbers = [[self.objectDictionary allKeys]sortedArrayUsingSelector:#selector(compare:)];
return idNumbers[row];
}
- (NSArray *)modelsForSection:(NSInteger)section row:(NSInteger)row
{
NSNumber *year = [self yearForSection:section];
NSNumber *idNumber = [self idForSection:section row:row];
return self.objectDictionary[year][idNumber];
}
// now we need a way to add objects that will put them into the correct place.
- (void)addModelObject:(Model *)model
{
NSNumber *modelYear = model.year;
NSNumber *modelId = model.idNumber;
// get the correct storage location out of the object dictionary
NSMutableDictionary *idDictionary = [self.objectDictionary[modelYear] mutableCopy];
// there is a better way to do this but can't think atm
if (!idDictionary) {
idDictionary = [NSMutableDictionary dictionary];
}
NSMutableArray *modelArray = [idDictionary[modelId] mutableCopy];
if (!modelArray) {
modelArray = [NSMutableArray array];
}
// insert the model in the correct place.
[modelArray addObject:model];
idDictionary[modelId] = modelArray;
self.objectDictionary[modelYear] = idDictionary;
}
#end
With all this set up you can now replace your complex function with this...
-(void) requestFinished: (ASIHTTPRequest *) request
{
NSString *theJSON = [request responseString];
SBJsonParser *parser = [[SBJsonParser alloc] init];
NSDictionary *jsonDictionary = [parser objectWithString:theJSON error:nil];
for (NSDictionary *dictionary in jsonDictionary)
{
Model *model = [[Model alloc]init];
model.cid = [dictionary valueForKey:#"cid"];
model.idNumber = [dictionary valueForKey:#"iid"];
model.year = [dictionary valueForKey:#"yr"];
model.val = [dictionary valueForKey:#"val"];
[self.objectStore addModelObject:model];
}
}
To get the models out for a particular row then just use...
[self.objectStore modelsForSection:indexPath.section row:indexPath.row];
To get the number of sections in the tableview delegate method...
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [self.objectStore numberOfYears];
}
No messing around with the model in the view controller.
Welcome to the MVC pattern.
There's a crap ton of code here but by placing all the code here you can remove all the complex code from your VC.
NSSet keeps only non-duplicate objects within themselves so to keep only unique objects in array you can use NSSet as -
Suppose you have array with duplicate objects
NSArray *arrayA = #[#"a", #"b", #"a", #"c", #"a"];
NSLog(#"arrayA is: %#", arrayA);
//create a set with the objects from above array as
//the set will not contain the duplicate objects from above array
NSSet *set = [NSSet setWithArray: arrayA];
// create another array from the objects of the set
NSArray *arrayB = [set allObjects];
NSLog(#"arrayB is: %#", set);
The output from the above looks like:
arrayA is: (
a,
b,
a,
c,
a
)
arrayB is: {(
b,
c,
a
)}
and to sort a mutable array in ascending order you can use NSSortDescriptor and sortUsingDescriptors:sortDescriptors. Also you need to provide the key on the basis of which array will be sorted.
NSSortDescriptor *sortDescriptor;
sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"key" ascending:YES];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
[array sortUsingDescriptors:sortDescriptors];
[sortDescriptor release];
Here you will get what you want.
//sort description will used to sort array.
NSSortDescriptor *descriptor=[[NSSortDescriptor alloc] initWithKey:#"iid" ascending:YES];
NSArray *descriptors=[NSArray arrayWithObject: descriptor];
NSArray *reverseOrder=[arrLeft sortedArrayUsingDescriptors:descriptors];
reverseOrder is your desire output.
there is another way you can sort objects that followed model.
NSArray *someArray = /* however you get an array */
NSArray *sortedArray = [someArray sortedArrayUsingComparator:^(id obj1, id obj2) {
NSNumber *rank1 = [obj1 valueForKeyPath:#"iid"];
NSNumber *rank2 = [obj2 valueForKeyPath:#"iid"];
return (NSComparisonResult)[rank1 compare:rank2];
}];
here sortedArray is our output.
you can replace same things for yr key as well.
This is what I did to sort the header data in ascending order and to remove duplicates from both header and leftmost column. Hope this will help others
NSOrderedSet *orderedSet3 = [NSOrderedSet orderedSetWithArray:head3];
headData3 = [[orderedSet3 array] mutableCopy];
[headData3 sortUsingComparator:^NSComparisonResult(NSString *str1, NSString *str2)
{
return [str1 compare:str2 options:(NSNumericSearch)];
}];
NSOrderedSet *orderedSet4 = [NSOrderedSet orderedSetWithArray:left3];
NSMutableArray *arrLeft3 = [[orderedSet4 array] mutableCopy];
[leftTableData3 addObject:arrLeft3];
I'm trying to add objects to an NSMutableArray but it keeps giving me this error.:
NSInternalInconsistencyException', reason: '-[__NSCFArray insertObject:atIndex:]: mutating method sent to immutable object
I have researched this problem, and I'm not doing anything wrong that past people have done, so I have no idea what's wrong. Here is my code:
Group.h
#property (strong, nonatomic) NSString *custom_desc;
#property (strong, nonatomic) NSMutableArray *attributes; //I define the array as mutable
Group.m
#import "Group.h"
#implementation Group
-(id)init
{
self = [super init];
if(self)
{
//do your object initialization here
self.attributes = [NSMutableArray array]; //I initialize the array to be a NSMutableArray
}
return self;
}
#end
GroupBuilder.m
#import "GroupBuilder.h"
#import "Group.h"
#implementation GroupBuilder
+ (NSArray *)groupsFromJSON:(NSData *)objectNotation error:(NSError **)error
{
NSError *localError = nil;
NSDictionary *parsedObject = [NSJSONSerialization JSONObjectWithData:objectNotation options:0 error:&localError];
if (localError != nil) {
*error = localError;
return nil;
}
NSMutableArray *groups = [[NSMutableArray alloc] init];
NSDictionary *results = [parsedObject objectForKey:#"result"];
NSArray *items = results[#"items" ];
for (NSDictionary *groupDic in items) {
Group *group = [[Group alloc] init];
for (NSString *key in groupDic) {
if ([group respondsToSelector:NSSelectorFromString(key)]) {
[group setValue:[groupDic valueForKey:key] forKey:key];
}
}
[groups addObject:group];
}
for(NSInteger i = 0; i < items.count; i++) {
//NSLog(#"%#", [[items objectAtIndex:i] objectForKey:#"attributes"]);
NSMutableArray *att = [[items objectAtIndex:i] objectForKey:#"attributes"]; //this returns a NSArray object understandable
Group *g = [groups objectAtIndex:i];
[g.attributes addObjectsFromArray:[att mutableCopy]]; //I use mutable copy here so that i'm adding objects from a NSMutableArray and not an NSArray
}
return groups;
}
#end
Use options:NSJSONReadingMutableContainers on your NSJSONSerialization call.
Then all the dictionaries and arrays it creates will be mutable.
According to the error message you are trying to insert an object into an instance of NSArray, not NSMutableArray.
I think it is here:
NSMutableArray *att = [[items objectAtIndex:i] objectForKey:#"attrib`enter code here`utes"]; //this returns a NSArray object understandable
Items is fetched from JSON and therefore not mutable. You can configure JSONSerialization in a way that it creates mutable objects, but how exactly I don't know out of the top of my head. Check the references on how to do that or make a mutable copy:
NSMutableArray *att = [[items objectAtIndex:i] objectForKey:#"attributes"] mutableCopy];
Next try, considering your replies to the first attempt:
#import "Group.h"
#implementation Group
-(NSMutableArray*)attributes
{
return [[super attributes] mutableCopy];
}
#end
I have a custom class which has a integer as a variable.
// addons.h
-(NSMutableArray *) goodDirections:(int)iNumber;
// addons.m
-(NSMutableArray *) goodDirections:(int)iNumber;
{
NSString *gOne = #"one"+iNumber;
NSString *gTwo = #"two"+iNumber;
NSString *gThree = #"three"+iNumber;
NSString *gFour = #"four"+iNumber;
NSMutableArray *goodValues = [NSMutableArray arrayWithObjects:gOne,gTwo,gThree,gFour,nil];
return goodValues;
}
// ViewController.m
addons *directions =[[addons alloc]init];
NSMutableArray *helloTest = [[NSMutableArray alloc]init];
helloTest = [directions goodDirections:3];
NSString *obj1 = [helloTest objectAtIndex:1];
NSLog(#"%#",obj1);
and the custom class has a variable number, when entered returns an array with 4 string values, how do I retrieve the values from the array in my implementation file viewController.m
Make sure you import the custom class in the file you want.Then
NSMutableArray *arr = [theObject simpleMethod:4];
To retrieve any object in arr, you can use objectAtIndex function (for example):
NSString *item = [arr objectAtIndex:1];
please! try below code snip
NSMutableArray *arr = [theObject simpleMethod:4];
obj = [arr objectAtIndex:0];
You can use array object at index.
NSMutableArray *arrayTemp = [self simpleMthod:2];
objTemp = [arrayTemp objectAtIndex:0];
Or You can use
for (int i=0; i<[arrayTemp count]; i++)
{
objTemp = [arrayTemp objectAtIndex:i];
}