iosSnippets/abstract_entities:_sortusingfunction:context:.m at master · bayon/iosSnippets · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
// abstract entities: sortUsingFunction:context:
//
//
// IDECodeSnippetCompletionScopes: [TopLevel]
// IDECodeSnippetIdentifier: 91DCF934-EE52-46C9-A29F-00BB451B4C41
// IDECodeSnippetLanguage: Xcode.SourceCodeLanguage.Objective-C
// IDECodeSnippetUserSnippet: 1
// IDECodeSnippetVersion: 2
 /*
 // abstract entities: sort array of custom objects:
  sort results from Core Data based on the entity type?


  Compare method

  Either you implement a compare-method for your object:

  - (NSComparisonResult)compare:(Person *)otherObject {
  return [self.birthDate compare:otherObject.birthDate];
  }

  NSArray *sortedArray;
  sortedArray = [drinkDetails sortedArrayUsingSelector:@selector(compare:)];
  NSSortDescriptor (better)

  or usually even better:

  NSSortDescriptor *sortDescriptor;
  sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"birthDate"
  ascending:YES];
  NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
  NSArray *sortedArray;
  sortedArray = [drinkDetails sortedArrayUsingDescriptors:sortDescriptors];
  You can easily sort by multiple keys by adding more than one to the array. Using custom comparator-methods is possible as well. Have a look at the documentation.

  Blocks (shiny!)

  There's also the possibility of sorting with a block since Mac OS X 10.6 and iOS 4:

  NSArray *sortedArray;
  sortedArray = [drinkDetails sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
  NSDate *first = [(Person*)a birthDate];
  NSDate *second = [(Person*)b birthDate];
  return [first compare:second];
  }];


  also:Sorting on type is not something a sort descriptor can do but a function can, as with

  -sortUsingFunction:context:

 */