Added a default mapping block for specific classes

Wasappli · Feb 29, 2016 · 6420958 · 6420958
1 parent 20c9afc
commit 6420958
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diff --git a/CHANGELOG b/CHANGELOG
@@ -1,3 +1,8 @@
+## 0.0.3 - Released Feb 29, 2015
+- Added `WANSCodingStore` to the main header
+- Added a way to register default mapping block for specific classes.
+For example, you can now add a default mapping block to turn `strings` to `NSDate`
+
 ## 0.0.2 - Released Feb 26, 2015
 - Exposed the store on WAMapper
 - Added a new store: `WANSCodingStore`

diff --git a/Files/WAMapper.h b/Files/WAMapper.h
@@ -7,6 +7,7 @@
 //
 
 @import Foundation;
+#import "WABlockMapping.h"
 
 @class WAEntityMapping;
 @protocol WAStoreProtocol;
@@ -44,6 +45,14 @@ typedef void (^WAMapperCompletionBlock)(NSArray *mappedObjects);
  */
 - (void)mapFromRepresentation:(id)json mapping:(WAEntityMapping *)mapping completion:(WAMapperCompletionBlock)completion;
 
+/**
+ *  Add a default mapping block for a class. For example, you could have an API returning dates all with the same format. You can register the transformation once here.
+ *
+ *  @param mappingBlock     the mapping block called to transform the value
+ *  @param destinationClass the destination class
+ */
+- (void)addDefaultMappingBlock:(WAMappingBlock)mappingBlock forDestinationClass:(Class)destinationClass;
+
 @property (nonatomic, strong, readonly) id <WAStoreProtocol> store;
 
 @end
diff --git a/Files/WAMapper.m b/Files/WAMapper.m
@@ -22,6 +22,7 @@
 @interface WAMapper ()
 
 @property (nonatomic, strong) id <WAStoreProtocol> store;
+@property (nonatomic, strong) NSMutableDictionary *defaultMappingBlocks;
 
 @end
 
@@ -55,6 +56,17 @@ - (void)mapFromRepresentation:(id)json mapping:(WAEntityMapping *)mapping comple
     completion(mappedObjects);
 }
 
+- (void)addDefaultMappingBlock:(WAMappingBlock)mappingBlock forDestinationClass:(Class)destinationClass {
+    WAMParameterAssert(destinationClass);
+    WAMParameterAssert(mappingBlock);
+
+    if (!self.defaultMappingBlocks) {
+        self.defaultMappingBlocks = [NSMutableDictionary dictionary];
+    }
+
+    self.defaultMappingBlocks[NSStringFromClass(destinationClass)] = mappingBlock;
+}
+
 #pragma mark - Private methods
 
 - (NSArray *)_mapFromRepresentation:(id)json mapping:(WAEntityMapping *)mapping {
@@ -171,14 +183,26 @@ - (NSArray *)_applyMapping:(WAEntityMapping *)mapping onObject:(id)object withRe
         }
 
         WAPropertyMapping *propertyMapping = mapping.attributeMappings[key];
+        id valueAfterMappingBlock = finalValue;
         if (finalValue) {
-            finalValue = propertyMapping.mappingBlock(finalValue);
+            valueAfterMappingBlock = propertyMapping.mappingBlock(finalValue);
+        }
+
+        if ([valueAfterMappingBlock isEqual:finalValue]) {
+            // This means that the property has no real transformation. Use global one
+            WAMappingBlock defaultMappingBlock = [self _defaultMappingBlockForDestinationClass:
+                                                  NSClassFromString([WAPropertyTransformation propertyTypeStringRepresentationFromPropertyName:propertyMapping.destinationPropertyName
+                                                                                                                                     forObject:object])];
+
+            if (defaultMappingBlock) {
+                valueAfterMappingBlock = defaultMappingBlock(finalValue);
+            }
         }
 
-        if ((!finalValue && [value isEqual:[NSNull null]])
+        if ((!valueAfterMappingBlock && [value isEqual:[NSNull null]])
             ||
-            finalValue) {
-            [object wa_setValueIfChanged:finalValue
+            valueAfterMappingBlock) {
+            [object wa_setValueIfChanged:valueAfterMappingBlock
                                   forKey:propertyMapping.destinationPropertyName];
         }
     }
@@ -284,4 +308,13 @@ - (NSArray *)_applyMapping:(WAEntityMapping *)mapping onObject:(id)object withRe
     return [relationShipObjects copy];
 }
 
+- (WAMappingBlock)_defaultMappingBlockForDestinationClass:(Class)destinationClass {
+    NSString *key = NSStringFromClass(destinationClass);
+    if (!key) {
+        return nil;
+    }
+
+    return self.defaultMappingBlocks[key];
+}
+
 @end
diff --git a/Files/WAPropertyTransformation.h b/Files/WAPropertyTransformation.h
@@ -11,6 +11,7 @@
 @interface WAPropertyTransformation : NSObject
 
 + (id)propertyValue:(id)initialValue fromPropertyName:(NSString *)propertyName forObject:(id)object;
++ (NSString *)propertyTypeStringRepresentationFromPropertyName:(NSString *)propertyName forObject:(id)object;
 + (BOOL)isClassACollection:(Class)class;
 + (BOOL)isClassAMutableCollection:(Class)class;
 + (id)convertObject:(id)object toClass:(Class)destinationClass;

diff --git a/Files/WAReverseMapper.h b/Files/WAReverseMapper.h
@@ -7,6 +7,7 @@
 //
 
 @import Foundation;
+#import "WABlockMapping.h"
 
 @class WAEntityMapping;
 
@@ -28,4 +29,12 @@ typedef BOOL (^WAReverseMapperShouldMapRelationshipBlock)(NSString *sourceRelati
  */
 - (NSArray <NSDictionary *>*)reverseMapObjects:(NSArray *)objects fromMapping:(WAEntityMapping *)mapping shouldMapRelationship:(WAReverseMapperShouldMapRelationshipBlock)shouldMapRelationshipBlock;
 
+/**
+ *  Add a reverse default mapping block for a class. For example, you could have an API returning dates all with the same format. You can register the transformation once here.
+ *
+ *  @param reverseMappingBlock the reverse mapping block called to transform the value
+ *  @param destinationClass    the destination class
+ */
+- (void)addReverseDefaultMappingBlock:(WAMappingBlock)reverseMappingBlock forDestinationClass:(Class)destinationClass;
+
 @end
diff --git a/Files/WAReverseMapper.m b/Files/WAReverseMapper.m
@@ -16,6 +16,12 @@
 
 #import "NSMutableDictionary+WASubDictionary.h"
 
+@interface WAReverseMapper ()
+
+@property (nonatomic, strong) NSMutableDictionary *defaultReverseMappingBlocks;
+
+@end
+
 @implementation WAReverseMapper
 
 - (NSArray *)reverseMapObjects:(NSArray *)objects fromMapping:(WAEntityMapping *)mapping shouldMapRelationship:(WAReverseMapperShouldMapRelationshipBlock)shouldMapRelationshipBlock {
@@ -51,6 +57,17 @@ - (NSArray *)reverseMapObjects:(NSArray *)objects fromMapping:(WAEntityMapping *
     return [allObjectsAsDictionaries copy];
 }
 
+- (void)addReverseDefaultMappingBlock:(WAMappingBlock)reverseMappingBlock forDestinationClass:(Class)destinationClass {
+    WAMParameterAssert(destinationClass);
+    WAMParameterAssert(reverseMappingBlock);
+
+    if (!self.defaultReverseMappingBlocks) {
+        self.defaultReverseMappingBlocks = [NSMutableDictionary dictionary];
+    }
+
+    self.defaultReverseMappingBlocks[NSStringFromClass(destinationClass)] = reverseMappingBlock;
+}
+
 #pragma mark - Private
 
 - (NSString *)_uniqueKeyForObject:(id)object mapping:(WAEntityMapping *)mapping {
@@ -85,10 +102,20 @@ - (NSDictionary *)_reverseMapObject:(id)object withMapping:(WAEntityMapping *)ma
     for (NSString *key in [reverseMapping allKeys]) {
         WAPropertyMapping *propertyMapping = reverseMapping[key];
 
-        id value = [object valueForKeyPath:key];
-        value = propertyMapping.reverseMappingBlock(value);
+        id value      = [object valueForKeyPath:key];
+        id finalValue = propertyMapping.reverseMappingBlock(value);
 
-        [objectAsDictionary wa_setObject:value ?: [NSNull null] byCreatingDictionariesForKeyPath:propertyMapping.sourcePropertyName];
+        if ([finalValue isEqual:value]) {
+            WAMappingBlock defaultReverseMappingBlock = [self _defaultReverseMappingBlockForDestinationClass:
+                                                         NSClassFromString([WAPropertyTransformation propertyTypeStringRepresentationFromPropertyName:propertyMapping.destinationPropertyName
+                                                                                                                                            forObject:object])];
+
+            if (defaultReverseMappingBlock) {
+                finalValue = defaultReverseMappingBlock(value);
+            }
+        }
+
+        [objectAsDictionary wa_setObject:finalValue ?: [NSNull null] byCreatingDictionariesForKeyPath:propertyMapping.sourcePropertyName];
     }
 
     // Map the relation ships
@@ -176,4 +203,13 @@ - (NSDictionary *)_removeRelationshipsValues:(NSDictionary *)originalRepresentat
     return [finalRepresentation copy];
 }
 
+- (WAMappingBlock)_defaultReverseMappingBlockForDestinationClass:(Class)destinationClass {
+    NSString *key = NSStringFromClass(destinationClass);
+    if (!key) {
+        return nil;
+    }
+
+    return self.defaultReverseMappingBlocks[key];
+}
+
 @end
diff --git a/README.md b/README.md
@@ -197,6 +197,55 @@ json = [reverseMapper reverseMapObjects:enterprises
                             fromMapping:enterpriseMapping
                   shouldMapRelationship:nil];
 ```
+
+# Default mappings
+If you have a server which returns all dates within the same format, then you can ask the mapper or the reverse mapper once to transform the value.
+
+Instead of writing
+
+```objc
+[enterpriseMapping addAttributeMappingsFromDictionary:@{
+                                                        @"id": @"itemID",
+                                                        @"name": @"name",
+                                                        @"address.street_number": @"streetNumber"
+                                                        }];      
+                                                   
+// Map custom values. Here an `NSDate` from a string using an `NSDateTransformer`
+[enterpriseMapping addMappingFromSourceProperty:@"creation_date"
+                          toDestinationProperty:@"creationDate"
+                                      withBlock:^id(id value) {
+                                          return [dateFormatter dateFromString:value];
+                                      }
+                                   reverseBlock:^id(id value) {
+                                       return [dateFormatter stringFromDate:value];
+                                   }];
+```
+
+You would write
+
+```objc
+[enterpriseMapping addAttributeMappingsFromDictionary:@{
+                                                        @"id": @"itemID",
+                                                        @"name": @"name",
+                                                        @"address.street_number": @"streetNumber",
+                                                        @"creation_date": @"creationDate"
+                                                        }];
+
+
+id(^toDateMappingBlock)(id ) = ^id(id value) {
+    if ([value isKindOfClass:[NSString class]]) {
+        return [dateFormatter dateFromString:value];
+    }
+
+    return value;
+};
+
+[mapper addDefaultMappingBlock:toDateMappingBlock
+           forDestinationClass:[NSDate class]];
+```
+
+The same thing happens to the reverse mapper. Note that if you provide a custom mapping on an `NSDate` object for a specific property (like a date with only the year), you can add the property to the entity mapping which will override the default behavior for this specific property.
+
 # Side notes
 ## TODOs
 

diff --git a/WAMapping.podspec b/WAMapping.podspec
@@ -1,12 +1,12 @@
 Pod::Spec.new do |s|
   s.name         = "WAMapping"
-  s.version      = "0.0.2"
+  s.version      = "0.0.3"
   s.summary      = "WAMapping is a library which turns dictionary to object and vice versa. Designed for speed!"
   s.homepage     = "https://github.com/Wasappli/WAMapping"
   s.license      = { :type => "MIT", :file => "LICENSE" }
   s.author       = { "Marian Paul" => "marian@wasapp.li" }
   s.platform     = :ios, "7.0"
-  s.source       = { :git => "https://github.com/Wasappli/WAMapping.git", :tag => "0.0.2" }
+  s.source       = { :git => "https://github.com/Wasappli/WAMapping.git", :tag => "0.0.3" }
   s.source_files = "Files/*.{h,m}"
   s.requires_arc = true
   s.frameworks   = "CoreData"

diff --git a/WAMappingTests/ClassicEnterpriseWithOneEmployee.json b/WAMappingTests/ClassicEnterpriseWithOneEmployee.json
@@ -7,6 +7,7 @@
     },
     "employees": [{
                   "id": 1,
-                  "first_name": "Marian"
+                  "first_name": "Marian",
+                  "birth_date": "1987"
                   }]
 }
diff --git a/WAMappingTests/Employee.h b/WAMappingTests/Employee.h
@@ -15,5 +15,6 @@
 @property (nonatomic, strong) NSNumber *itemID;
 @property (nonatomic, strong) NSString *firstName;
 @property (nonatomic, strong) Enterprise *enterprise;
+@property (nonatomic, strong) NSDate *birthDate;
 
 @end
diff --git a/WAMappingTests/EmployeeCD+CoreDataProperties.h b/WAMappingTests/EmployeeCD+CoreDataProperties.h
@@ -18,6 +18,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nullable, nonatomic, retain) NSNumber *itemID;
 @property (nullable, nonatomic, retain) NSString *firstName;
 @property (nullable, nonatomic, retain) EnterpriseCD *enterprise;
+@property (nullable, nonatomic, retain) NSDate *birthDate;
 
 @end
 

diff --git a/WAMappingTests/EmployeeCD+CoreDataProperties.m b/WAMappingTests/EmployeeCD+CoreDataProperties.m
@@ -16,5 +16,6 @@ @implementation EmployeeCD (CoreDataProperties)
 @dynamic itemID;
 @dynamic firstName;
 @dynamic enterprise;
+@dynamic birthDate;
 
 @end
diff --git a/WAMappingTests/Model.xcdatamodeld/Model.xcdatamodel/contents b/WAMappingTests/Model.xcdatamodeld/Model.xcdatamodel/contents
@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<model userDefinedModelVersionIdentifier="" type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="9525" systemVersion="15B42" minimumToolsVersion="Xcode 7.0">
+<model userDefinedModelVersionIdentifier="" type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="9525" systemVersion="14F27" minimumToolsVersion="Xcode 7.0">
     <entity name="Employee" representedClassName="EmployeeCD" syncable="YES">
+        <attribute name="birthDate" optional="YES" attributeType="Date" syncable="YES"/>
         <attribute name="firstName" optional="YES" attributeType="String" syncable="YES"/>
         <attribute name="itemID" optional="YES" attributeType="Integer 16" defaultValueString="0" syncable="YES"/>
         <relationship name="enterprise" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="Enterprise" inverseName="employees" inverseEntity="Enterprise" syncable="YES"/>
@@ -15,7 +16,7 @@
         <relationship name="orderedEmployees" optional="YES" toMany="YES" deletionRule="Nullify" ordered="YES" destinationEntity="Employee" syncable="YES"/>
     </entity>
     <elements>
-        <element name="Employee" positionX="-63" positionY="-18" width="128" height="90"/>
+        <element name="Employee" positionX="-63" positionY="-18" width="128" height="105"/>
         <element name="Enterprise" positionX="-54" positionY="9" width="128" height="150"/>
     </elements>
 </model>