├── AOPAspect
    ├── AOPAspect.xcodeproj
    │   ├── project.pbxproj
    │   └── project.xcworkspace
    │   │   └── contents.xcworkspacedata
    └── AOPAspect
    │   ├── AOPAspect-Prefix.pch
    │   ├── AOPAspect.h
    │   └── AOPAspect.m
└── README.md


/AOPAspect/AOPAspect.xcodeproj/project.pbxproj:
--------------------------------------------------------------------------------
  1 | // !$*UTF8*$!
  2 | {
  3 | 	archiveVersion = 1;
  4 | 	classes = {
  5 | 	};
  6 | 	objectVersion = 46;
  7 | 	objects = {
  8 | 
  9 | /* Begin PBXBuildFile section */
 10 | 		3A04D7B914CABE1D00A2852F /* Foundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 3A04D7B814CABE1D00A2852F /* Foundation.framework */; };
 11 | 		3A04D7BF14CABE1D00A2852F /* AOPAspect.m in Sources */ = {isa = PBXBuildFile; fileRef = 3A04D7BE14CABE1D00A2852F /* AOPAspect.m */; };
 12 | 		3AF77A2414D716F200F5D77E /* AOPAspect.h in Headers */ = {isa = PBXBuildFile; fileRef = 3A04D7BD14CABE1D00A2852F /* AOPAspect.h */; settings = {ATTRIBUTES = (Public, ); }; };
 13 | /* End PBXBuildFile section */
 14 | 
 15 | /* Begin PBXFileReference section */
 16 | 		3A04D7B514CABE1D00A2852F /* libAOPAspect.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = libAOPAspect.a; sourceTree = BUILT_PRODUCTS_DIR; };
 17 | 		3A04D7B814CABE1D00A2852F /* Foundation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Foundation.framework; path = System/Library/Frameworks/Foundation.framework; sourceTree = SDKROOT; };
 18 | 		3A04D7BC14CABE1D00A2852F /* AOPAspect-Prefix.pch */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "AOPAspect-Prefix.pch"; sourceTree = "<group>"; };
 19 | 		3A04D7BD14CABE1D00A2852F /* AOPAspect.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = AOPAspect.h; sourceTree = "<group>"; };
 20 | 		3A04D7BE14CABE1D00A2852F /* AOPAspect.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = AOPAspect.m; sourceTree = "<group>"; };
 21 | /* End PBXFileReference section */
 22 | 
 23 | /* Begin PBXFrameworksBuildPhase section */
 24 | 		3A04D7B214CABE1D00A2852F /* Frameworks */ = {
 25 | 			isa = PBXFrameworksBuildPhase;
 26 | 			buildActionMask = 2147483647;
 27 | 			files = (
 28 | 				3A04D7B914CABE1D00A2852F /* Foundation.framework in Frameworks */,
 29 | 			);
 30 | 			runOnlyForDeploymentPostprocessing = 0;
 31 | 		};
 32 | /* End PBXFrameworksBuildPhase section */
 33 | 
 34 | /* Begin PBXGroup section */
 35 | 		3A04D7AA14CABE1D00A2852F = {
 36 | 			isa = PBXGroup;
 37 | 			children = (
 38 | 				3A04D7BA14CABE1D00A2852F /* AOPAspect */,
 39 | 				3A04D7B714CABE1D00A2852F /* Frameworks */,
 40 | 				3A04D7B614CABE1D00A2852F /* Products */,
 41 | 			);
 42 | 			sourceTree = "<group>";
 43 | 		};
 44 | 		3A04D7B614CABE1D00A2852F /* Products */ = {
 45 | 			isa = PBXGroup;
 46 | 			children = (
 47 | 				3A04D7B514CABE1D00A2852F /* libAOPAspect.a */,
 48 | 			);
 49 | 			name = Products;
 50 | 			sourceTree = "<group>";
 51 | 		};
 52 | 		3A04D7B714CABE1D00A2852F /* Frameworks */ = {
 53 | 			isa = PBXGroup;
 54 | 			children = (
 55 | 				3A04D7B814CABE1D00A2852F /* Foundation.framework */,
 56 | 			);
 57 | 			name = Frameworks;
 58 | 			sourceTree = "<group>";
 59 | 		};
 60 | 		3A04D7BA14CABE1D00A2852F /* AOPAspect */ = {
 61 | 			isa = PBXGroup;
 62 | 			children = (
 63 | 				3A04D7BD14CABE1D00A2852F /* AOPAspect.h */,
 64 | 				3A04D7BE14CABE1D00A2852F /* AOPAspect.m */,
 65 | 				3A04D7BB14CABE1D00A2852F /* Supporting Files */,
 66 | 			);
 67 | 			path = AOPAspect;
 68 | 			sourceTree = "<group>";
 69 | 		};
 70 | 		3A04D7BB14CABE1D00A2852F /* Supporting Files */ = {
 71 | 			isa = PBXGroup;
 72 | 			children = (
 73 | 				3A04D7BC14CABE1D00A2852F /* AOPAspect-Prefix.pch */,
 74 | 			);
 75 | 			name = "Supporting Files";
 76 | 			sourceTree = "<group>";
 77 | 		};
 78 | /* End PBXGroup section */
 79 | 
 80 | /* Begin PBXHeadersBuildPhase section */
 81 | 		3A04D7B314CABE1D00A2852F /* Headers */ = {
 82 | 			isa = PBXHeadersBuildPhase;
 83 | 			buildActionMask = 2147483647;
 84 | 			files = (
 85 | 				3AF77A2414D716F200F5D77E /* AOPAspect.h in Headers */,
 86 | 			);
 87 | 			runOnlyForDeploymentPostprocessing = 0;
 88 | 		};
 89 | /* End PBXHeadersBuildPhase section */
 90 | 
 91 | /* Begin PBXNativeTarget section */
 92 | 		3A04D7B414CABE1D00A2852F /* AOPAspect */ = {
 93 | 			isa = PBXNativeTarget;
 94 | 			buildConfigurationList = 3A04D7C214CABE1D00A2852F /* Build configuration list for PBXNativeTarget "AOPAspect" */;
 95 | 			buildPhases = (
 96 | 				3A04D7B114CABE1D00A2852F /* Sources */,
 97 | 				3A04D7B214CABE1D00A2852F /* Frameworks */,
 98 | 				3A04D7B314CABE1D00A2852F /* Headers */,
 99 | 			);
100 | 			buildRules = (
101 | 			);
102 | 			dependencies = (
103 | 			);
104 | 			name = AOPAspect;
105 | 			productName = AOPAspect;
106 | 			productReference = 3A04D7B514CABE1D00A2852F /* libAOPAspect.a */;
107 | 			productType = "com.apple.product-type.library.static";
108 | 		};
109 | /* End PBXNativeTarget section */
110 | 
111 | /* Begin PBXProject section */
112 | 		3A04D7AC14CABE1D00A2852F /* Project object */ = {
113 | 			isa = PBXProject;
114 | 			attributes = {
115 | 				LastUpgradeCheck = 0420;
116 | 			};
117 | 			buildConfigurationList = 3A04D7AF14CABE1D00A2852F /* Build configuration list for PBXProject "AOPAspect" */;
118 | 			compatibilityVersion = "Xcode 3.2";
119 | 			developmentRegion = English;
120 | 			hasScannedForEncodings = 0;
121 | 			knownRegions = (
122 | 				en,
123 | 			);
124 | 			mainGroup = 3A04D7AA14CABE1D00A2852F;
125 | 			productRefGroup = 3A04D7B614CABE1D00A2852F /* Products */;
126 | 			projectDirPath = "";
127 | 			projectRoot = "";
128 | 			targets = (
129 | 				3A04D7B414CABE1D00A2852F /* AOPAspect */,
130 | 			);
131 | 		};
132 | /* End PBXProject section */
133 | 
134 | /* Begin PBXSourcesBuildPhase section */
135 | 		3A04D7B114CABE1D00A2852F /* Sources */ = {
136 | 			isa = PBXSourcesBuildPhase;
137 | 			buildActionMask = 2147483647;
138 | 			files = (
139 | 				3A04D7BF14CABE1D00A2852F /* AOPAspect.m in Sources */,
140 | 			);
141 | 			runOnlyForDeploymentPostprocessing = 0;
142 | 		};
143 | /* End PBXSourcesBuildPhase section */
144 | 
145 | /* Begin XCBuildConfiguration section */
146 | 		3A04D7C014CABE1D00A2852F /* Debug */ = {
147 | 			isa = XCBuildConfiguration;
148 | 			buildSettings = {
149 | 				ALWAYS_SEARCH_USER_PATHS = NO;
150 | 				ARCHS = "$(ARCHS_STANDARD_32_BIT)";
151 | 				CLANG_ENABLE_OBJC_ARC = YES;
152 | 				COPY_PHASE_STRIP = NO;
153 | 				GCC_C_LANGUAGE_STANDARD = gnu99;
154 | 				GCC_DYNAMIC_NO_PIC = NO;
155 | 				GCC_OPTIMIZATION_LEVEL = 0;
156 | 				GCC_PREPROCESSOR_DEFINITIONS = (
157 | 					"DEBUG=1",
158 | 					"$(inherited)",
159 | 				);
160 | 				GCC_SYMBOLS_PRIVATE_EXTERN = NO;
161 | 				GCC_VERSION = com.apple.compilers.llvm.clang.1_0;
162 | 				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
163 | 				GCC_WARN_ABOUT_RETURN_TYPE = YES;
164 | 				GCC_WARN_UNUSED_VARIABLE = YES;
165 | 				IPHONEOS_DEPLOYMENT_TARGET = 5.0;
166 | 				SDKROOT = iphoneos;
167 | 			};
168 | 			name = Debug;
169 | 		};
170 | 		3A04D7C114CABE1D00A2852F /* Release */ = {
171 | 			isa = XCBuildConfiguration;
172 | 			buildSettings = {
173 | 				ALWAYS_SEARCH_USER_PATHS = NO;
174 | 				ARCHS = "$(ARCHS_STANDARD_32_BIT)";
175 | 				CLANG_ENABLE_OBJC_ARC = YES;
176 | 				COPY_PHASE_STRIP = YES;
177 | 				GCC_C_LANGUAGE_STANDARD = gnu99;
178 | 				GCC_VERSION = com.apple.compilers.llvm.clang.1_0;
179 | 				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
180 | 				GCC_WARN_ABOUT_RETURN_TYPE = YES;
181 | 				GCC_WARN_UNUSED_VARIABLE = YES;
182 | 				IPHONEOS_DEPLOYMENT_TARGET = 5.0;
183 | 				SDKROOT = iphoneos;
184 | 				VALIDATE_PRODUCT = YES;
185 | 			};
186 | 			name = Release;
187 | 		};
188 | 		3A04D7C314CABE1D00A2852F /* Debug */ = {
189 | 			isa = XCBuildConfiguration;
190 | 			buildSettings = {
191 | 				DSTROOT = /tmp/AOPAspect.dst;
192 | 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
193 | 				GCC_PREFIX_HEADER = "AOPAspect/AOPAspect-Prefix.pch";
194 | 				OTHER_LDFLAGS = "-ObjC";
195 | 				PRODUCT_NAME = "$(TARGET_NAME)";
196 | 				SKIP_INSTALL = YES;
197 | 			};
198 | 			name = Debug;
199 | 		};
200 | 		3A04D7C414CABE1D00A2852F /* Release */ = {
201 | 			isa = XCBuildConfiguration;
202 | 			buildSettings = {
203 | 				DSTROOT = /tmp/AOPAspect.dst;
204 | 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
205 | 				GCC_PREFIX_HEADER = "AOPAspect/AOPAspect-Prefix.pch";
206 | 				OTHER_LDFLAGS = "-ObjC";
207 | 				PRODUCT_NAME = "$(TARGET_NAME)";
208 | 				SKIP_INSTALL = YES;
209 | 			};
210 | 			name = Release;
211 | 		};
212 | /* End XCBuildConfiguration section */
213 | 
214 | /* Begin XCConfigurationList section */
215 | 		3A04D7AF14CABE1D00A2852F /* Build configuration list for PBXProject "AOPAspect" */ = {
216 | 			isa = XCConfigurationList;
217 | 			buildConfigurations = (
218 | 				3A04D7C014CABE1D00A2852F /* Debug */,
219 | 				3A04D7C114CABE1D00A2852F /* Release */,
220 | 			);
221 | 			defaultConfigurationIsVisible = 0;
222 | 			defaultConfigurationName = Release;
223 | 		};
224 | 		3A04D7C214CABE1D00A2852F /* Build configuration list for PBXNativeTarget "AOPAspect" */ = {
225 | 			isa = XCConfigurationList;
226 | 			buildConfigurations = (
227 | 				3A04D7C314CABE1D00A2852F /* Debug */,
228 | 				3A04D7C414CABE1D00A2852F /* Release */,
229 | 			);
230 | 			defaultConfigurationIsVisible = 0;
231 | 			defaultConfigurationName = Release;
232 | 		};
233 | /* End XCConfigurationList section */
234 | 	};
235 | 	rootObject = 3A04D7AC14CABE1D00A2852F /* Project object */;
236 | }
237 | 


--------------------------------------------------------------------------------
/AOPAspect/AOPAspect.xcodeproj/project.xcworkspace/contents.xcworkspacedata:
--------------------------------------------------------------------------------
1 | <?xml version="1.0" encoding="UTF-8"?>
2 | <Workspace
3 |    version = "1.0">
4 |    <FileRef
5 |       location = "self:AOPAspect.xcodeproj">
6 |    </FileRef>
7 | </Workspace>
8 | 


--------------------------------------------------------------------------------
/AOPAspect/AOPAspect/AOPAspect-Prefix.pch:
--------------------------------------------------------------------------------
1 | //
2 | // Prefix header for all source files of the 'AOPAspect' target in the 'AOPAspect' project
3 | //
4 | 
5 | #ifdef __OBJC__
6 |     #import <Foundation/Foundation.h>
7 | #endif
8 | 


--------------------------------------------------------------------------------
/AOPAspect/AOPAspect/AOPAspect.h:
--------------------------------------------------------------------------------
 1 | //
 2 | //  AOPAspect.h
 3 | //  AOPAspect
 4 | //
 5 | //  Created by Andras Koczka on 1/21/12.
 6 | //  Copyright (c) 2012 Andras Koczka
 7 | //
 8 | //  Permission is hereby granted, free of charge, to any person obtaining a copy
 9 | //  of this software and associated documentation files (the "Software"), to deal
10 | //  in the Software without restriction, including without limitation the rights
11 | //  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 | //  copies of the Software, and to permit persons to whom the Software is furnished
13 | //  to do so, subject to the following conditions:
14 | //
15 | //  The above copyright notice and this permission notice shall be included
16 | //  in all copies or substantial portions of the Software.
17 | //
18 | //  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 | //  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
20 | //  FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
21 | //  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
22 | //  IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23 | //  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 | //
25 | 
26 | #import <Foundation/Foundation.h>
27 | 
28 | typedef void (^aspect_block_t)(NSInvocation *invocation);
29 | 
30 | @interface AOPAspect : NSObject
31 | 
32 | // Intercept methods return an identifier that can be used for deregistration with the removeInterceptorWithIdentifier method
33 | // Only instance methods can be intercepted
34 | - (NSString *)interceptClass:(Class)aClass beforeExecutingSelector:(SEL)selector usingBlock:(aspect_block_t)block;
35 | - (NSString *)interceptClass:(Class)aClass afterExecutingSelector:(SEL)selector usingBlock:(aspect_block_t)block;
36 | - (NSString *)interceptClass:(Class)aClass insteadExecutingSelector:(SEL)selector usingBlock:(aspect_block_t)block;
37 | 
38 | // Removes an interceptor block
39 | - (void)removeInterceptorWithIdentifier:(NSString *)identifier;
40 | 
41 | // Use this method to get the AOPAspect instance. Don't use alloc/init.
42 | + (AOPAspect *)instance;
43 | 
44 | @end
45 | 


--------------------------------------------------------------------------------
/AOPAspect/AOPAspect/AOPAspect.m:
--------------------------------------------------------------------------------
  1 | //
  2 | //  AOPAspect.m
  3 | //  AOPAspect
  4 | //
  5 | //  Created by Andras Koczka on 1/21/12.
  6 | //  Copyright (c) 2012 Andras Koczka
  7 | //
  8 | //  Permission is hereby granted, free of charge, to any person obtaining a copy
  9 | //  of this software and associated documentation files (the "Software"), to deal
 10 | //  in the Software without restriction, including without limitation the rights
 11 | //  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 12 | //  copies of the Software, and to permit persons to whom the Software is furnished
 13 | //  to do so, subject to the following conditions:
 14 | //
 15 | //  The above copyright notice and this permission notice shall be included
 16 | //  in all copies or substantial portions of the Software.
 17 | //
 18 | //  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 19 | //  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 20 | //  FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 21 | //  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 22 | //  IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 23 | //  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 24 | //
 25 | 
 26 | #import "AOPAspect.h"
 27 | #import <objc/runtime.h>
 28 | #import <objc/message.h>
 29 | 
 30 | 
 31 | #pragma mark - Type definitions and keys
 32 | 
 33 | 
 34 | typedef enum {
 35 |     AOPAspectInspectorTypeBefore = 0,
 36 |     AOPAspectInspectorTypeInstead = 1,
 37 |     AOPAspectInspectorTypeAfter = 2
 38 | }AOPAspectInspectorType;
 39 | 
 40 | static NSString *const AOPAspectCurrentObjectKey = @"AOPAspectCurrentObjectKey";
 41 | 
 42 | 
 43 | #pragma mark - Shared instance
 44 | 
 45 | 
 46 | static AOPAspect *aspectManager = NULL;
 47 | 
 48 | 
 49 | #pragma mark - Implementation
 50 | 
 51 | 
 52 | @implementation AOPAspect {
 53 |     
 54 |     // interceptorStorage (dict) -> interceptorTypes (dict) -> interceptors (array) -> interceptor (dict) -> block
 55 |     NSMutableDictionary *interceptorStorage; // Ok, this is ugly
 56 |     
 57 |     aspect_block_t methodInvoker;
 58 |     dispatch_queue_t synchronizerQueue;
 59 | }
 60 | 
 61 | 
 62 | #pragma mark - Object lifecycle
 63 | 
 64 | 
 65 | + (void)initialize {
 66 |     static dispatch_once_t onceToken;
 67 |     dispatch_once(&onceToken, ^{
 68 |         aspectManager = [[AOPAspect alloc] init];
 69 |         aspectManager->interceptorStorage = [[NSMutableDictionary alloc] init];
 70 |         
 71 |         // Create queue for synchronization
 72 |         aspectManager->synchronizerQueue = dispatch_queue_create("Synchronizer queue - AOPAspect", DISPATCH_QUEUE_SERIAL);
 73 | 
 74 |         // Store the default method invoker block
 75 |         aspectManager->methodInvoker = ^(NSInvocation *invocation) {
 76 |             // Invoke the original method
 77 |             [invocation invoke];
 78 |         };
 79 |     });
 80 | }
 81 | 
 82 | + (AOPAspect *)instance {
 83 |     return aspectManager;
 84 | }
 85 | 
 86 | - (void)dealloc {
 87 |     dispatch_release(synchronizerQueue);
 88 | }
 89 | 
 90 | 
 91 | #pragma mark - Helper methods
 92 | 
 93 | 
 94 | - (NSString *)keyWithClass:(Class)aClass selector:(SEL)selector {
 95 |     return [NSString stringWithFormat:@"%@%@", NSStringFromClass(aClass), NSStringFromSelector(selector)];
 96 | }
 97 | 
 98 | - (SEL)extendedSelectorWithClass:(Class)aClass selector:(SEL)selector {
 99 |     return NSSelectorFromString([self keyWithClass:aClass selector:selector]);
100 | }
101 | 
102 | // Stores the current class in the thread dictionary.
103 | - (void)setCurrentObject:(id)anObject {
104 |     [[[NSThread currentThread] threadDictionary] setObject:anObject forKey:AOPAspectCurrentObjectKey];
105 | }
106 | 
107 | - (id)currentObject {
108 |     return [[[NSThread currentThread] threadDictionary] objectForKey:AOPAspectCurrentObjectKey];
109 | }
110 | 
111 | - (Class)currentClass {
112 |     return [[[[NSThread currentThread] threadDictionary] objectForKey:AOPAspectCurrentObjectKey] class];
113 | }
114 | 
115 | - (NSString *)identifierWithClass:(Class)aClass selector:(SEL)aSelector dictionary:(NSDictionary *)dictionary {
116 |     return [NSString stringWithFormat:@"%@ | %@ | %p", NSStringFromClass(aClass), NSStringFromSelector(aSelector), dictionary];
117 | }
118 | 
119 | #pragma mark - Interceptor registration
120 | 
121 | - (void)restoreOriginalMethodWithClass:(Class)aClass selector:(SEL)aSelector {
122 | 
123 |     Method method = class_getInstanceMethod(aClass, aSelector);
124 |     IMP implementation;
125 |     
126 |     if ([[aClass instanceMethodSignatureForSelector:aSelector] methodReturnLength] > sizeof(double)) {
127 |         implementation = class_getMethodImplementation_stret([self class], [self extendedSelectorWithClass:aClass selector:aSelector]);
128 |     }
129 |     else {
130 |         implementation = class_getMethodImplementation([self class], [self extendedSelectorWithClass:aClass selector:aSelector]);
131 |     }
132 | 
133 |     method_setImplementation(method, implementation);
134 | }
135 | 
136 | - (void)interceptMethodWithClass:(Class)aClass selector:(SEL)aSelector {
137 |     
138 |     Method method = class_getInstanceMethod(aClass, aSelector);
139 |     IMP implementation;
140 |     
141 |     // Check method return type
142 |     if ([[aClass instanceMethodSignatureForSelector:aSelector] methodReturnLength] > sizeof(double)) {
143 |         implementation = (IMP)_objc_msgForward_stret;
144 |     }
145 |     else {
146 |         implementation = (IMP)_objc_msgForward;
147 |     }
148 |     
149 |     // Change the implementation
150 |     method_setImplementation(method, implementation);
151 | }
152 | 
153 | - (NSString *)storeInterceptorBlock:(aspect_block_t)block withClass:(Class)aClass selector:(SEL)aSelector type:(AOPAspectInspectorType)type {
154 |     
155 |     NSString *key = [self keyWithClass:aClass selector:aSelector];
156 | 
157 |     // Get the type dictionary
158 |     NSMutableDictionary *interceptorTypeDictionary = [interceptorStorage objectForKey:key];
159 |     
160 |     // Create a type dictionary if needed
161 |     if (!interceptorTypeDictionary) {
162 |         interceptorTypeDictionary = [[NSMutableDictionary alloc] init];
163 |         [interceptorStorage setObject:interceptorTypeDictionary forKey:key];
164 |     }
165 |     
166 |     // Get the interceptors array
167 |     NSMutableArray *interceptors = [interceptorTypeDictionary objectForKey:[NSNumber numberWithInt:type]];
168 |     
169 |     // Initialize a new array (if needed) for storing interceptors. One array for each type: before, instead, after
170 |     if (!interceptors) {
171 |         interceptors = [[NSMutableArray alloc] init];
172 |         [interceptorTypeDictionary setObject:interceptors forKey:[NSNumber numberWithInt:type]];
173 |     }
174 |     
175 |     // Wrap the interceptor into an NSDictionary so its address will be unique
176 |     NSDictionary *interceptor = [NSDictionary dictionaryWithObject:block forKey:[NSDate date]];
177 |     
178 |     // Remove the default methodinvoker in case of a new "instead" type interceptor
179 |     if (type == AOPAspectInspectorTypeInstead && interceptors.count == 1) {
180 |         if ([[[interceptors lastObject] allValues] lastObject] == (id)methodInvoker) {
181 |             [interceptors removeLastObject];
182 |         }
183 |     }
184 |     
185 |     [interceptors addObject:interceptor];
186 |     
187 |     // Return a unique identifier that can be used to identify a certain interceptor
188 |     return [self identifierWithClass:aClass selector:aSelector dictionary:interceptor];
189 | }
190 | 
191 | - (NSString *)registerClass:(Class)aClass withSelector:(SEL)aSelector type:(AOPAspectInspectorType)type usingBlock:(aspect_block_t)block {
192 |     NSParameterAssert(aClass);
193 |     NSParameterAssert(aSelector);
194 |     NSParameterAssert(block);
195 |     
196 |     // Hook a new method
197 |     if (![self respondsToSelector:[self extendedSelectorWithClass:aClass selector:aSelector]]) {
198 |         
199 |         // Get the instance method
200 |         Method method = class_getInstanceMethod(aClass, aSelector);
201 |         NSAssert(method, @"No instance method found for the given selector. Only instance methods can be intercepted.");
202 |         
203 |         IMP implementation;
204 |         NSMethodSignature *methodSignature = [aClass instanceMethodSignatureForSelector:aSelector];
205 |         
206 |         // Get the original method implementation
207 |         if ([methodSignature methodReturnLength] > sizeof(double)) {
208 |             implementation = class_getMethodImplementation_stret(aClass, aSelector);
209 |         }
210 |         else {
211 |             implementation = class_getMethodImplementation(aClass, aSelector);
212 |         }
213 | 
214 |         [self interceptMethodWithClass:aClass selector:aSelector];
215 |         
216 |         // Get the forwarding method properties
217 |         SEL forwardingMethodSelector = @selector(forwardingTargetForSelector:);
218 |         IMP forwardingMethodImplementation = class_getMethodImplementation([self class], @selector(baseClassForwardingTargetForSelector:));
219 |         Method forwardingMethod = class_getInstanceMethod([self class], @selector(baseClassForwardingTargetForSelector:));
220 |         const char *forwardingMethodTypeEncoding = method_getTypeEncoding(forwardingMethod);
221 |         
222 |         // Add the original forwarding method with the extended selector to self
223 |         IMP originalForwardingMethodImp = class_getMethodImplementation(aClass, forwardingMethodSelector);
224 |         SEL extendedForwardingSelector = [self extendedSelectorWithClass:aClass selector:forwardingMethodSelector];
225 |         class_addMethod([self class], extendedForwardingSelector, originalForwardingMethodImp, forwardingMethodTypeEncoding);
226 | 
227 |         // Initiate hook to self on the base object
228 |         class_replaceMethod(aClass, forwardingMethodSelector, forwardingMethodImplementation, forwardingMethodTypeEncoding);
229 | 
230 |         SEL extendedSelector = [self extendedSelectorWithClass:aClass selector:aSelector];
231 |         const char *typeEncoding = method_getTypeEncoding(method);
232 |         
233 |         // Add the original method with the extended selector to self
234 |         class_addMethod([self class], extendedSelector, implementation, typeEncoding);
235 | 
236 |         // Add the default method invoker block
237 |         dispatch_sync(synchronizerQueue, ^{
238 |             [self storeInterceptorBlock:methodInvoker withClass:aClass selector:aSelector type:AOPAspectInspectorTypeInstead];
239 |         });
240 |     }
241 |     
242 |     // Store the interceptor block
243 |     __block NSString *identifier;
244 |     dispatch_sync(synchronizerQueue, ^{
245 |         identifier = [self storeInterceptorBlock:block withClass:aClass selector:aSelector type:type];
246 |     });
247 |     
248 |     return identifier;
249 | }
250 | 
251 | - (NSString *)interceptClass:(Class)aClass beforeExecutingSelector:(SEL)selector usingBlock:(aspect_block_t)block {
252 |     return [self registerClass:aClass withSelector:selector type:AOPAspectInspectorTypeBefore usingBlock:block];
253 | }
254 | 
255 | - (NSString *)interceptClass:(Class)aClass afterExecutingSelector:(SEL)selector usingBlock:(aspect_block_t)block {
256 |     return [self registerClass:aClass withSelector:selector type:AOPAspectInspectorTypeAfter usingBlock:block];
257 | }
258 | 
259 | - (NSString *)interceptClass:(Class)aClass insteadExecutingSelector:(SEL)selector usingBlock:(aspect_block_t)block {
260 |     return [self registerClass:aClass withSelector:selector type:AOPAspectInspectorTypeInstead usingBlock:block];
261 | }
262 | 
263 | - (void)deregisterMethodWithClass:(Class)aClass selector:(SEL)aSelector {
264 |     
265 |     [self restoreOriginalMethodWithClass:aClass selector:aSelector];
266 |     [interceptorStorage removeObjectForKey:[self keyWithClass:aClass selector:aSelector]];
267 | }
268 | 
269 | - (void)removeInterceptorWithIdentifier:(NSString *)identifier {
270 | 
271 |     // Get the class and the selector from the identifier
272 |     NSArray *components = [identifier componentsSeparatedByString:@" | "];
273 |     Class aClass = NSClassFromString([components objectAtIndex:0]);
274 |     SEL selector = NSSelectorFromString([components objectAtIndex:1]);
275 |     
276 |     dispatch_sync(synchronizerQueue, ^{
277 |         
278 |         // Search for the interceptor that belongs to the given identifier
279 |         for (NSDictionary *interceptorTypeDictionary in [interceptorStorage allValues]) {
280 |             NSInteger interceptorCount = 0;
281 |             
282 |             for (int i = 0; i < 3; i++) {
283 |                 NSMutableArray *interceptors = [interceptorTypeDictionary objectForKey:[NSNumber numberWithInt:i]];
284 |                 
285 |                 for (NSDictionary *dictionary in [NSArray arrayWithArray:interceptors]) {
286 |                     
287 |                     // If found remove the interceptor
288 |                     if ([[self identifierWithClass:aClass selector:selector dictionary:dictionary] isEqualToString:identifier]) {
289 |                         [interceptors removeObject:dictionary];
290 |                         
291 |                         // Add back the default method invoker block in case of no more "instead" type blocks
292 |                         if (i == AOPAspectInspectorTypeInstead && interceptors.count == 0) {
293 |                             [self storeInterceptorBlock:methodInvoker withClass:aClass selector:selector type:i];
294 |                         }
295 |                     }
296 |                 }
297 |                 
298 |                 interceptorCount += interceptors.count;
299 |             }
300 |             
301 |             // If only the default methodinvoker interceptor remained than deregister the method to improve performance
302 |             if (interceptorCount == 1 && [[[[interceptorTypeDictionary objectForKey:[NSNumber numberWithInt:AOPAspectInspectorTypeInstead]] lastObject] allValues] lastObject] == (id)methodInvoker) {
303 |                 [self deregisterMethodWithClass:aClass selector:selector];
304 |             }
305 |         }
306 |     });
307 | }
308 | 
309 | 
310 | #pragma mark - Hook
311 | 
312 | 
313 | - (id)baseClassForwardingTargetForSelector:(SEL)aSelector {
314 |     
315 |     // In case the selector is not implemented on the base class
316 |     if (![self respondsToSelector:aSelector]) {
317 |         SEL extendedForwardingMethodSelector = [[AOPAspect instance] extendedSelectorWithClass:[self class] selector:@selector(forwardingTargetForSelector:)];
318 |         
319 |         // Invoke the original forwardingTargetForSelector method
320 |         return method_invoke([AOPAspect instance], class_getInstanceMethod([AOPAspect class], extendedForwardingMethodSelector), aSelector);
321 |     }
322 |     
323 |     // Store the current class
324 |     [[AOPAspect instance] setCurrentObject:self];
325 |     
326 |     return [AOPAspect instance];
327 | }
328 | 
329 | - (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector {
330 |     return [[self currentClass] instanceMethodSignatureForSelector:aSelector];
331 | }
332 | 
333 | - (void)executeInterceptorsWithClass:(Class)aClass selector:(SEL)aSelector invocation:(NSInvocation *)anInvocation {
334 |     
335 |     NSString *key = [self keyWithClass:aClass selector:aSelector];
336 |     __block NSMutableDictionary *interceptorTypeDictionary;
337 |     
338 |     dispatch_sync(synchronizerQueue, ^{
339 |         interceptorTypeDictionary = [interceptorStorage objectForKey:key];
340 |     });
341 | 
342 |     // Restore original state - this is needed for self and _cmd to be valid
343 |     // FIXME: this could cause issues between threads
344 |     [aspectManager restoreOriginalMethodWithClass:aClass selector:aSelector];
345 |     
346 |     // Executes interceptors before, instead and after
347 |     for (int i = 0; i < 3; i++) {
348 |         __block NSArray *interceptors;
349 | 
350 |         dispatch_sync(synchronizerQueue, ^{
351 |             interceptors = [NSArray arrayWithArray:[interceptorTypeDictionary objectForKey:[NSNumber numberWithInt:i]]];
352 |         });
353 | 
354 |         for (NSDictionary *interceptor in interceptors) {
355 |             aspect_block_t block = [[interceptor allValues] lastObject];
356 |             block(anInvocation);
357 |         }
358 |     }
359 |     
360 |     // Restore interception
361 |     [aspectManager interceptMethodWithClass:aClass selector:aSelector];
362 | }
363 | 
364 | - (void)forwardInvocation:(NSInvocation *)anInvocation {
365 | 
366 |     anInvocation.target = [self currentObject];
367 |     [self executeInterceptorsWithClass:[self currentClass] selector:anInvocation.selector invocation:anInvocation];
368 | }
369 | 
370 | @end
371 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 | AOPAspect is a small aspect oriented programming library for iOS. Licensed under the MIT license.
2 | 
3 | **Note:** Current implementation is **not thread safe**. Also there is a **bug** when intercepting the same method in subclasses when it is only implemented on the superclass. If all the subclasses override the method than it works OK. I will try to fix these in the next few days.
4 | 
5 | For more information on how it works, please check out the my article:
6 | 
7 | <http://codeshaker.blogspot.com/2012/01/aop-delivered.html>
8 | 


--------------------------------------------------------------------------------