Another implementation: NSNull -> nil (replace NSNull -> [NSDictionary dictionary]) (#701)

Author: wolfcon

Example/MJExtensionExample/main.h

@@ -20,6 +20,7 @@ void keyValuesArray2objectArray(void);
 void object2keyValues(void);
 void objectArray2keyValuesArray(void);
 void coreData(void);
+void nullSituations(void);
 void coding(void);
 void replacedKeyFromPropertyName121(void);
 void newValueFromOldValue(void);

Example/MJExtensionExample/main.m

@@ -50,6 +50,7 @@ int main(int argc, char * argv[]) {
         execute(replacedKeyFromPropertyName121, @"统一转换属性名（比如驼峰转下划线）");
         execute(newValueFromOldValue, @"过滤字典的值（比如字符串日期处理为NSDate、字符串nil处理为@""）");
         execute(logAllProperties, @"使用MJExtensionLog打印模型的所有属性");
+        execute(nullSituations, @"测试有关 Null 的情况");
 
         return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
     }
@@ -250,7 +251,6 @@ void keyValuesArray2objectArray()
                                @"name" : @"Jack",
                                @"icon" : @"lufy.png",
                                },
-                           
                            @{
                                @"name" : @"Rose",
                                @"icon" : @"nami.png",
@@ -323,7 +323,6 @@ void objectArray2keyValuesArray()
     MJUser *user2 = [[MJUser alloc] init];
     user2.name = @"Rose";
     user2.icon = @"nami.png";
-    
     NSArray *userArray = @[user1, user2];
 
     // 2.将模型数组转为字典数组
@@ -356,6 +355,46 @@ void coreData()
     MJExtensionLog(@"name=%@, icon=%@, age=%d, height=%@, money=%@, sex=%d, gay=%d", user.name, user.icon, user.age, user.height, user.money, user.sex, user.gay);
 }
 
+void nullSituations() {
+    NSNull *null = [NSNull null];
+    id obj2 = [null mj_keyValues];
+    MJExtensionLog(@"%@", obj2);
+    
+    MJUser *user1 = [[MJUser alloc] init];
+    user1.name = @"user1";
+    MJUser *user2 = [[MJUser alloc] init];
+    user2.name = @"user2";
+    NSArray *users = @[user1, [NSNull null], user2];
+    NSArray *usersDictArr = [MJUser mj_keyValuesArrayWithObjectArray:users];
+    MJExtensionLog(@"%@", usersDictArr);
+    NSString *str = [usersDictArr mj_JSONObject];
+    MJExtensionLog(@"%@", str);
+    
+    
+    NSArray *dictArray = @[
+                           @{
+                               @"name" : @"Jack",
+                               @"icon" : @"lufy.png",
+                               },
+                           [NSNull null],
+                           @{
+                               @"name" : @"Rose",
+                               @"icon" : @"nami.png",
+                               }
+                           ];
+    
+    NSArray *userArray = [MJUser mj_objectArrayWithKeyValuesArray:dictArray];
+    MJExtensionLog(@"%@", userArray);
+    
+    
+    NSDictionary *dic = @{
+                          @"name": [NSNull null],
+                          @"icon": @"lufy.png"
+                          };
+    MJUser *testNull = [MJUser mj_objectWithKeyValues:dic];
+    MJExtensionLog(@"%@", testNull);
+}
+
 /**
  * NSCoding示例
  */

MJExtension/MJFoundation.m

@@ -22,7 +22,6 @@ + (BOOL)isClassFromFoundation:(Class)c
     dispatch_once(&onceToken, ^{
         // 集合中没有NSObject，因为几乎所有的类都是继承自NSObject，具体是不是NSObject需要特殊判断
         foundationClasses = [NSSet setWithObjects:
-                             [NSNull class],
                              [NSURL class],
                              [NSDate class],
                              [NSValue class],

MJExtension/NSObject+MJKeyValue.m

@@ -307,6 +307,11 @@ - (NSMutableDictionary *)mj_keyValuesWithIgnoredKeys:(NSArray *)ignoredKeys
 - (NSMutableDictionary *)mj_keyValuesWithKeys:(NSArray *)keys ignoredKeys:(NSArray *)ignoredKeys
 {
     // 如果自己不是模型类, 那就返回自己
+    // 模型类过滤掉 NSNull
+    // 唯一一个不返回自己的
+    if ([self isMemberOfClass:NSNull.class]) { return nil; }
+    // 这里虽然返回了自己, 但是其实是有报错信息的.
+    // TODO: 报错机制不好, 需要重做
     MJExtensionAssertError(![MJFoundation isClassFromFoundation:[self class]], (NSMutableDictionary *)self, [self class], @"不是自定义的模型类")
 
     id keyValues = [NSMutableDictionary dictionary];
@@ -426,9 +431,13 @@ + (NSMutableArray *)mj_keyValuesArrayWithObjectArray:(NSArray *)objectArray keys
     NSMutableArray *keyValuesArray = [NSMutableArray array];
     for (id object in objectArray) {
         if (keys) {
-            [keyValuesArray addObject:[object mj_keyValuesWithKeys:keys]];
+            id convertedObj = [object mj_keyValuesWithKeys:keys];
+            if (!convertedObj) { continue; }
+            [keyValuesArray addObject:convertedObj];
         } else {
-            [keyValuesArray addObject:[object mj_keyValuesWithIgnoredKeys:ignoredKeys]];
+            id convertedObj = [object mj_keyValuesWithIgnoredKeys:ignoredKeys];
+            if (!convertedObj) { continue; }
+            [keyValuesArray addObject:convertedObj];
         }
     }
     return keyValuesArray;