Changeset 15384 in webkit for trunk/JavaScriptCore

Timestamp:

Jul 12, 2006, 2:55:55 AM (19 years ago)

Author:

mjs

Message:

4eviewed by Geoff.

• add handling of hasInstance callback for API objects

• API/JSCallbackObject.cpp: (KJS::JSCallbackObject::implementsHasInstance): Check if callback is present. (KJS::JSCallbackObject::hasInstance): Invoke appropriate callback.
• API/JSCallbackObject.h:
• API/JSClassRef.cpp:
• API/JSObjectRef.h:
• API/testapi.c: (MyObject_hasInstance): Test case; should match what construct would do.
• API/testapi.js:

Location:

trunk/JavaScriptCore

Files:

• API/JSCallbackObject.cpp (modified) (1 diff)
• API/JSCallbackObject.h (modified) (1 diff)
• API/JSClassRef.cpp (modified) (1 diff)
• API/JSObjectRef.h (modified) (5 diffs)
• API/testapi.c (modified) (2 diffs)
• API/testapi.js (modified) (1 diff)
• ChangeLog (modified) (1 diff)

trunk/JavaScriptCore/API/JSCallbackObject.cpp

@@ -236 +236 @@
 }
 
+bool JSCallbackObject::implementsHasInstance() const
+{
+    for (JSClassRef jsClass = m_class; jsClass; jsClass = jsClass->parent)
+        if (jsClass->callbacks.hasInstance)
+            return true;
+
+    return false;
+}
+
+bool JSCallbackObject::hasInstance(ExecState *exec, JSValue *value)
+{
+    JSContextRef execRef = toRef(exec);
+    JSObjectRef thisRef = toRef(this);
+
+    for (JSClassRef jsClass = m_class; jsClass; jsClass = jsClass->parent)
+        if (JSObjectHasInstanceCallback hasInstance = jsClass->callbacks.hasInstance)
+            return hasInstance(execRef, thisRef, toRef(value), toRef(exec->exceptionSlot()));
+
+    ASSERT(0); // implementsHasInstance should prevent us from reaching here
+    return 0;
+}
+
+
 bool JSCallbackObject::implementsCall() const
 {

trunk/JavaScriptCore/API/JSCallbackObject.h

@@ -55 +55 @@
     virtual JSObject* construct(ExecState*, const List& args);
 
+    virtual bool implementsHasInstance() const;
+    virtual bool hasInstance(ExecState *exec, JSValue *value);
+
     virtual bool implementsCall() const;
     virtual JSValue* callAsFunction(ExecState*, JSObject* thisObj, const List &args);

trunk/JavaScriptCore/API/JSClassRef.cpp

@@ -31 +31 @@
 using namespace KJS;
 
-const JSObjectCallbacks kJSObjectCallbacksNone = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+const JSObjectCallbacks kJSObjectCallbacksNone = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
 JSClassRef JSClassCreate(JSStaticValue* staticValues, JSStaticFunction* staticFunctions, const JSObjectCallbacks* callbacks, JSClassRef parentClass)

trunk/JavaScriptCore/API/JSObjectRef.h

@@ -194 +194 @@
 /*! 
 @typedef JSObjectCallAsConstructorCallback
-@abstract The callback invoked when an object is used as a constructor in a 'new' statement.
+@abstract The callback invoked when an object is used as a constructor in a 'new' expression.
 @param context The current execution context.
 @param constructor A JSObject that is the constructor being called.
@@ -207 +207 @@
 If your callback were invoked by the JavaScript expression 'new myConstructorFunction()', constructor would be set to myConstructorFunction.
 
-If this callback is NULL, using your object as a constructor in a 'new' statement will throw an exception.
+If this callback is NULL, using your object as a constructor in a 'new' expression will throw an exception.
 */
 typedef JSObjectRef 
 (*JSObjectCallAsConstructorCallback) (JSContextRef context, JSObjectRef constructor, size_t argc, JSValueRef argv[], JSValueRef* exception);
+
+/*! 
+@typedef JSObjectHasInstanceCallback
+@abstract The callback invoked when an object is used in an 'instanceof' expression.
+@param context The current execution context.
+@param constructor The JSObject receiving the hasInstance request
+@param possibleInstance The JSValue being tested to determine if it is an instance of constructor.
+@param exception A pointer to a JSValueRef in which to return an exception, if any.
+@result true if possibleInstance is an instance of constructor, otherwise false
+
+@discussion If you named your function HasInstance, you would declare it like this:
+
+bool HasInstance(JSContextRef context, JSObjectRef constructor, JSValueRef possibleInstance, JSValueRef* exception);
+
+If your callback were invoked by the JavaScript expression 'someValue instanceof myObject', constructor would be set to myObject and possibleInstance would be set to someValue..
+
+If this callback is NULL, using your object in an 'instanceof' will always return false.
+
+Standard JavaScript practice calls for objects that implement the callAsConstructor callback to implement the hasInstance callback as well.
+*/
+typedef bool 
+(*JSObjectHasInstanceCallback)  (JSContextRef context, JSObjectRef constructor, JSValueRef possibleInstance, JSValueRef* exception);
 
 /*! 
@@ -241 +263 @@
 @field getPropertyList The callback invoked when adding an object's properties to a property list.
 @field callAsFunction The callback invoked when an object is called as a function.
-@field callAsConstructor The callback invoked when an object is used as a constructor in a 'new' statement.
+@field hasInstance The callback invoked when an object is used in an 'instanceof' expression.
+@field callAsConstructor The callback invoked when an object is used as a constructor in a 'new' expression.
 @field convertToType The callback invoked when converting an object to a particular JavaScript type.
 */
@@ -255 +278 @@
     JSObjectCallAsFunctionCallback      callAsFunction;
     JSObjectCallAsConstructorCallback   callAsConstructor;
+    JSObjectHasInstanceCallback         hasInstance;
     JSObjectConvertToTypeCallback       convertToType;
 } JSObjectCallbacks;
@@ -344 +368 @@
 @abstract Convenience method for creating a JavaScript constructor with a given callback as its implementation.
 @param context The execution context to use.
-@param callAsConstructor The JSObjectCallAsConstructorCallback to invoke when the constructor is used in a 'new' statement.
+@param callAsConstructor The JSObjectCallAsConstructorCallback to invoke when the constructor is used in a 'new' expression.
 @result A JSObject that is a constructor. The object's prototype will be the default object prototype.
 */

trunk/JavaScriptCore/API/testapi.c

@@ -201 +201 @@
 }
 
+static bool MyObject_hasInstance(JSContextRef context, JSObjectRef constructor, JSValueRef possibleValue, JSValueRef* exception)
+{
+    UNUSED_PARAM(context);
+
+    JSStringRef numberString = JSStringCreateWithUTF8CString("Number");
+    JSObjectRef numberConstructor = JSValueToObject(context, JSObjectGetProperty(context, JSContextGetGlobalObject(context), numberString));
+    JSStringRelease(numberString);
+
+    return JSValueIsInstanceOfConstructor(context, possibleValue, numberConstructor);
+}
+
 static JSValueRef MyObject_convertToType(JSContextRef context, JSObjectRef object, JSType type, JSValueRef* exception)
 {
@@ -229 +240 @@
 JSObjectCallbacks MyObject_callbacks = {
     0,
-    &MyObject_initialize,
-    &MyObject_finalize,
-    &MyObject_hasProperty,
-    &MyObject_getProperty,
-    &MyObject_setProperty,
-    &MyObject_deleteProperty,
-    &MyObject_getPropertyList,
-    &MyObject_callAsFunction,
-    &MyObject_callAsConstructor,
-    &MyObject_convertToType,
+    MyObject_initialize,
+    MyObject_finalize,
+    MyObject_hasProperty,
+    MyObject_getProperty,
+    MyObject_setProperty,
+    MyObject_deleteProperty,
+    MyObject_getPropertyList,
+    MyObject_callAsFunction,
+    MyObject_callAsConstructor,
+    MyObject_hasInstance,
+    MyObject_convertToType,
 };
 

trunk/JavaScriptCore/API/testapi.js

@@ -82 +82 @@
 shouldBe("typeof constructedObject", "object");
 shouldBe("constructedObject.value", 1);
+shouldBe("(new MyObject()) instanceof MyObject", true);
+shouldBe("(new Object()) instanceof MyObject", false);

trunk/JavaScriptCore/ChangeLog

@@ +1 @@
+2006-07-12  Maciej Stachowiak  <[email protected]>
+
+        4eviewed by Geoff.
+        
+        - add handling of hasInstance callback for API objects
+
+        * API/JSCallbackObject.cpp:
+        (KJS::JSCallbackObject::implementsHasInstance): Check if callback is present.
+        (KJS::JSCallbackObject::hasInstance): Invoke appropriate callback.
+        * API/JSCallbackObject.h:
+        * API/JSClassRef.cpp:
+        * API/JSObjectRef.h:
+        * API/testapi.c:
+        (MyObject_hasInstance): Test case; should match what construct would do.
+        * API/testapi.js:
+
 2006-07-11  Geoffrey Garen  <[email protected]>