Recently I needed to create object from a JSON response in IOS. After some researching and fooling around with some ios libraries. I could not find something simple and easy to use. Most of the libraries are doing more then just creating objects from the JSON. So I decided too look into on how much trouble it could be to create this myself. In this post I will explain in detail what I did to make my own Objects from JSON without using any libraries that take space for stuff you don’t need.
So for example you have the next JSON:
{
"identifier": "511d5f71ad0234001251e5a5",
"action": "pass",
"point": "1500",
"geolocation": [
"13.3904",
"52.506433"]
}
And want to have an simple object that can refer to this data as easy as testObject.identifier or testObject action. All we need to do is create a new class. And do the following in the .h file for every JSON atribute:
@interface OBTestObject : NSObject
@property(nonatomic, strong) NSString *identifier;
@property(nonatomic, strong) NSString *action;
@property(nonatomic, copy) NSNumber * point;
@property(nonatomic, copy) NSArray *geolocation;
@end
And do the following in the .m file
@implementation OBTestObject
//This for catching unknown properties
-(void)setValue:(id)value forUndefinedKey:(NSString*)key
{
NSLog(@"Error: setting unknown key: %@ with data: %@", key, value);
}
-(void)encodeWithCoder:(NSCoder*)encoder
{
[encoder encodeObject:self. identifier forKey:@"identifier"];
[encoder encodeObject:self.action forKey:@"action"];
[encoder encodeObject:self.point forKey:@"point"];
[encoder encodeObject:self.geolocation forKey:@"geolocation"];
}
-(id)initWithCoder:(NSCoder*)decoder
{
self = [super init];
if (self) {
self.identifier = [decoder decodeObjectForKey:@"identifier"];
self.action = [decoder decodeObjectForKey:@"action"];
self.point = [decoder decodeObjectForKey:@"point"];
self.geolocation = [decoder decodeObjectForKey:@"geolocation"];
}
return self;
}
@end
Ok so now we have setup the whole model and can be used as follow.
OBTestObject* testObject = [[OBTestObject alloc]
[testObject setValuesForKeysWithDictionary:JSON];
and thats it, now all the values from the JSON are mapped to the object you just made and can be used easily.
This can be done even with custom objects in the JSON. I will explain this as a second part.
