Changeset 15384 in webkit for trunk/JavaScriptCore/API/JSObjectRef.h

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:

File:

• trunk/JavaScriptCore/API/JSObjectRef.h (modified) (5 diffs)

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.
 */