Key Value Coding is a mechanism for accessing an object’s properties indirectly, using strings to identify properties, rather than through invocation of an accessor method or accessing them directly through instance variables.
References
Questions tagged [kvc]
193 questions
0
votes
3 answers
Is there a more elegant way of finding unique NSDictionary keys within an NSArray?
Aim: To obtain an NSArray containing unique keys for given NSDictionary(s) using elegant code
Example Code with Current Working Solution:
NSArray *data = [[NSArray alloc] initWithObjects:
[NSDictionary…
So Over It
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votes
1 answer
KVC valueForKey return a __NSCFConstantString instead a __NSCFString
I use KVC in my projects.
And, in one of my classes, I wrote the property :
@property ( nonatomic, strong ) NSString *notes;
I want to put a NSString object in that property :
And before setting the value, I want to test the…
Chrstpsln
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2 answers
understanding simple collection operators
I am reading Apple's Key Value Programming Guide.
In the topic, Simple Collection Operators, I read:
The following example returns the average value of the transaction amount for the objects in transactions:
NSNumber…
Rounak
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1 answer
Create an NSManagedObject with the contents of a NSMutableDictionary (may have NSCFString in place of number)
I want to create an NSManagedObject with the contents of a NSMutableDictionary and Visa Versa. KVC doesn't work properly in NSManagedObject so i cant use
[managedObject setValue:@"1" forKey:@"testKey"];
here managedObject has a property "NSNumber…
Yogesh Maheshwari
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-1
votes
1 answer
About forKeyPath
I am following this tutorial to get to know KVC.
stated in that tutorial the following
[someObject.someProperty setText:@"This is a text"];
Using KVC:
[self setValue:@"this is a text"
forKeyPath:@"someObject.someProperty.text"]
my questions…
Amrmsmb
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1 answer
"this class is not key value coding-compliant for the key" error when shortening UI elements on Apple Watch Extension
I'm taking the watchOS2Sampler project available online and trying to experiment with adding a Picker to the "Gradation" Scene, which currently has two buttons at bottom and an image in the middle. My goal is to try and control an image's location…
Locksleyu
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votes
1 answer
IOS/Objective-C: Error Converting JSON to Object
I am trying to convert JSON array to object for display in table. I am able to capture JSON. However, when I try to turn into object, I get error shown below. There is definitely a property named "name" in object class.
- (void)fetchedData:(NSData…
user1904273
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-1
votes
1 answer
KVC Accessor Patterns for Trees
In this document, Apple describes Accessor Patterns for To-One and To-Many properties. To-Many properties cover Indexed and Unordered collections.
Which brings me to the question:
Is there a different Accessor Pattern for tree structures, or should…
insys
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votes
1 answer
KVC release objs using valueForKeyPath?
I have a lot of objects named _Obj_1, _Obj_2, etc...
And I want to release all.
I'm using KVC. In particular to release all, i use:
MyClass *obj = nil;
for ( int i=1 ; i<=14; i++ ) {
obj = [self valueForKeyPath:[NSString…
elp
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votes
2 answers
how can i access to UINavigationController with the string name
my app has the navController
and at run time I have
NSString *propertyName = @"navController";
and I know it is a type of UINavigationController
how can i access to UINavigationController with the string name
I might need to use…
ramo
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-2
votes
1 answer
Setting CAEmitterLayer properties with KVC
I am attempting to to change properties on a CAEmitterLayer instance dynamically. I am making a call to setValue:forKey: like this: [self.mainViewController.mainView.spaceView.emitterLayer setValue:[NSNumber numberWithFloat:0]…
Alexander Bollbach
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-2
votes
3 answers
Looping through an array of dynamic objects
I'm not really sure exactly how to describe what I want to do - the best I can do is provide some code as an example:
- (void) doStuffInLoopForDataArray:(NSArray *)arr forObjectsOfClass:(NSString *)class
{
for ([class class] *obj in arr)
…
GeneralMike
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votes
1 answer
Swift optional property using KVC causes crash
I found that using KVC in Swift causes many problems, especially with optional properties.
Here is my specific problem:
Here is a Class named Person. It has a normal property called age,and a Optional(Int) property called ageOptional.
class Person:…
charlin
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