From eedfd60b41edf3648848a3d7a1f3f7e24feba7b5 Mon Sep 17 00:00:00 2001
From: Stephen Celis <stephen@stephencelis.com>
Date: Thu, 27 Mar 2014 13:18:50 -0700
Subject: [PATCH] Support descending/multiple string ordering

E.g.,

  // Descending
  [Person order:@"firstName DESC"];

  // Multiple
  [Person order:@"lastName, firstName"];

  // Multiple, descending
  [Person order:@"lastName DESC, firstName DESC"];

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
---
 Classes/NSManagedObject+ActiveRecord.m            | 15 ++++++++++++++-
 .../SampleProjectTests/FindersAndCreatorsTests.m  | 14 +++++++++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/Classes/NSManagedObject+ActiveRecord.m b/Classes/NSManagedObject+ActiveRecord.m
index 478d5f9..f02f83e 100644
--- a/Classes/NSManagedObject+ActiveRecord.m
+++ b/Classes/NSManagedObject+ActiveRecord.m
@@ -261,12 +261,22 @@ + (NSSortDescriptor *)sortDescriptorFromDictionary:(NSDictionary *)dict {
                                          ascending:isAscending];
 }
 
++ (NSSortDescriptor *)sortDescriptorFromString:(NSString *)order {
+    NSArray *components = [order split];
+
+    NSString *key = [components firstObject];
+    NSString *value = [components count] > 1 ? components[1] : @"ASC";
+
+    return [self sortDescriptorFromDictionary:@{key: value}];
+
+}
+
 + (NSSortDescriptor *)sortDescriptorFromObject:(id)order {
     if ([order isKindOfClass:[NSSortDescriptor class]])
         return order;
 
     if ([order isKindOfClass:[NSString class]])
-        return [NSSortDescriptor sortDescriptorWithKey:order ascending:YES];
+        return [self sortDescriptorFromString:order];
 
     if ([order isKindOfClass:[NSDictionary class]])
         return [self sortDescriptorFromDictionary:order];
@@ -275,6 +285,9 @@ + (NSSortDescriptor *)sortDescriptorFromObject:(id)order {
 }
 
 + (NSArray *)sortDescriptorsFromObject:(id)order {
+    if ([order isKindOfClass:[NSString class]])
+        order = [order componentsSeparatedByString:@","];
+
     if ([order isKindOfClass:[NSArray class]])
         return [order map:^id (id object) {
             return [self sortDescriptorFromObject:object];
diff --git a/Example/SampleProjectTests/FindersAndCreatorsTests.m b/Example/SampleProjectTests/FindersAndCreatorsTests.m
index a58910a..c5a8a97 100644
--- a/Example/SampleProjectTests/FindersAndCreatorsTests.m
+++ b/Example/SampleProjectTests/FindersAndCreatorsTests.m
@@ -140,12 +140,24 @@ void createSomePeople(NSArray *names, NSArray *surnames, NSManagedObjectContext
                              [NSManagedObjectContext defaultContext]);
         });
 
-        it(@"orders results by a single property", ^{
+        it(@"orders results by a single string property", ^{
             NSArray *resultLastNames = [[Person allWithOrder:@"lastName"]
                                         map:lastNameMapper];
             [[resultLastNames should] equal:@[@"Gaz", @"Mol", @"Mol", @"Zed"]];
         });
 
+        it(@"orders results by a single string property descending", ^{
+            NSArray *resultFirstNames = [[Person allWithOrder:@"firstName DESC"]
+                                         map:firstNameMapper];
+            [[resultFirstNames should] equal:@[@"Don", @"Cal", @"Bob", @"Abe"]];
+        });
+
+        it(@"orders results by multiple string properties descending", ^{
+            NSArray *resultFirstNames = [[Person allWithOrder:@"lastName, firstName DESC"]
+                                         map:firstNameMapper];
+            [[resultFirstNames should] equal:@[@"Cal", @"Don", @"Bob", @"Abe"]];
+        });
+
         it(@"orders results by multiple properties", ^{
             NSArray *resultFirstNames = [[Person allWithOrder:@[@"lastName", @"firstName"]]
                                          map:firstNameMapper];