NSPredicate on multilevel response - ios

Question

My response is like;
{
Writers : [
{
"name": "Mad Decent Block Party NYC",
"artist": [
{
"artist_name": "Dillon Francis",
"name": "Dillon Francis",
"Books" : ["Book1", "Book2", "Book3"]
},
{
"artist_name": "Major Lazer",
"name": "Major Lazer",
"Books" : ["Book4", "Book5", "Book6"]
},
{
"artist_name": "Flosstradamus ",
"name": "Flosstradamus",
"Books" : ["Book7", "Book8", "Book9"]
}
],
},{
"name": "Kaskade Atmosphere Tour NYC",
"artist": [
{
"artist_name": "Ryan Raddon",
"name": "Kaskade",
"Books" : ["Book1", "Book2", "Book3"]
}
],
},
]
}
I want to search through Books array on each dict of artist array. When text matches result should be total dict object from writers array along with matched books objects.
For example my search is for Book1, result should look like,
Writers : [
{
"artist": [
{
"artist_name": "Dillon Francis",
"name": "Dillon Francis",
"Books" : ["Book1", "Book2", "Book3"]
},
],
"name": "Mad Decent Block Party NYC",
},{
"artist": [
{
"artist_name": "Ryan Raddon",
"name": "Kaskade",
"Books" : ["Book1", "Book2", "Book3"]
}
],
"name": "Kaskade Atmosphere Tour NYC",
},
]

Answer 1

You just need to write two lines of code for this. You form a predicate, and filter the writers array with the predicate.
You can use the keypaths in the predicate, and check if the book array contains the given book name.
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"ANY artist.Books contains[cd] 'Book1'"];
NSArray *arr = [responseDict[#"Writers"] filteredArrayUsingPredicate:predicate];
This should work.

Answer 2

NSPredicate *predicate = [NSPredicate predicateWithFormat: #"ANY artist.Books CONTAINS[cd] %#", #"Book1"];
NSArray *temp = [[sampleDic objectForKey:#"Writers"] filteredArrayUsingPredicate:predicate];
This is the first thing i thought, but looking at your dictionary structure, i think this will not work for you. But if you want to recreate your structure to:
#{
#"Writers":
#[
#{
#"name" :#"name1",
#"artist" :#[ #"Books":[...] ]
},
#{
#"name" :#"name2",
#"artist" :#[ #"Books":[...] ]
},
#{
#"name" :#"name3",
#"artist" :#[ #"Books":[...] ]
}
]
};
it will.
This is not the best solution but i think this will work for you..
Sample input:
NSDictionary *sampleDic = #{
#"Writers":
#[
#{
#"name" :#"Mad Decent Block Party NYC",
#"artist" :#[
#{
#"artist_name":#"Dillon Francis",
#"name": #"Dillon Francis",
#"Books" : #[#"Book1", #"Book2", #"Book3"]
},
#{
#"artist_name":#"Major Lazer",
#"name": #"Major Lazer",
#"Books" : #[#"Book4", #"Book5", #"Book6"]
},
#{
#"artist_name":#"Flosstradamus",
#"name": #"Flosstradamus",
#"Books" : #[#"Book7", #"Book8", #"Book9"]
}
]
},
#{
#"name" :#"Kaskade Atmosphere Tour NYC",
#"artist" :#[
#{
#"artist_name":#"Ryan Raddon",
#"name": #"Kaskade",
#"Books" : #[#"Book1", #"Book2", #"Book3"]
}
]
}
]
};
And the filtering:
- (NSDictionary *)filterDictionary:(NSDictionary *)sampleDic withBookName:(NSString *)bookName
{
NSMutableArray *compiledArr = [[NSMutableArray alloc] init];
for (NSDictionary *itemDic in [sampleDic objectForKey:#"Writers"])
{
NSArray *itemDicKeys = [itemDic allKeys];
for (int i = 0; i < itemDicKeys.count; i++)
{
if ([itemDicKeys[i] isEqual:#"artist"])
{
NSPredicate *predicate = [NSPredicate predicateWithFormat: #"SELF['Books'] CONTAINS[cd] %#", bookName];
NSArray *tempResult = [[itemDic objectForKey:itemDicKeys[i]] filteredArrayUsingPredicate:predicate];
NSDictionary *result = #{#"name": [itemDic objectForKey:#"name"],
#"artist": tempResult};
[compiledArr addObject:result];
}
}
}
NSDictionary *resultDic = #{#"Writer":compiledArr};
return resultDic;
}
Using it like: NSLog(#"tempResult :%#", [self filterDictionary:sampleDic withBookName:#"Book1"]);
Result is: