Subj : helper macros for accessing the jsapi
To   : netscape.public.mozilla.jseng
From : stefan noll
Date : Mon Aug 01 2005 02:38 am

hi,

some time ago i wrote some helper macros for accessing the jsapi. 
perhaps there are usefull for somebody:

header file:
> #ifdef LINUX
> #define XP_UNIX
> #endif
> 
> #ifdef WIN32
> #define XP_WIN
> #endif
> 
> #include "jsapi.h"
> 
> extern int32 Jsval_AsInt(JSContext *cx, jsval v);
> 
> extern jsdouble Jsval_AsDouble(JSContext *cx, jsval v);
> 
> #define JSVAL_AS_STRING(x) JS_GetStringBytes(JS_ValueToString(cx,x))
> #define JSVAL_AS_INT(x) Jsval_AsInt(cx,x)
> #define JSVAL_AS_DOUBLE(x) Jsval_AsDouble(cx,x)
> 
> 	/* JS Class Functions */
> #define DEFINE_JSCLASS \
> 	static JSBool JSGetProperty(JSContext *cx, JSObject *obj, jsval id, jsval *vp);\
> 	static JSBool JSSetProperty(JSContext *cx, JSObject *obj, jsval id, jsval *vp);\
> 	static JSBool JSConstructor(JSContext *cx, JSObject *obj, uintN argc, \
> 		jsval *argv, jsval *rval);\
> 	static void JSDestructor(JSContext *cx, JSObject *obj);\
> 	static JSObject *JSInit(JSContext *cx, JSObject *obj, JSObject *proto);\
> 	static JSObject *JSInitGlobal(JSContext *cx, JSObject *obj, const char* Name=0); \
> 	\
> 	static JSClass JsClass;\
> 	static JSPropertySpec JsProperties[];\
> 	static JSFunctionSpec JsMethods[]; 
> 
> 
> 
> 
> #define IMPLEMENT_JSINIT(c) IMPLEMENT_JSINIT_ARGS(c, 0);
> 
> 
> 
> 
> #define IMPLEMENT_JSINIT_ARGS(c,args)\
> 	JSObject *c::JSInit(JSContext *cx, JSObject *obj, JSObject *proto)\
> 	{\
> 		JSObject *newObj = JS_InitClass(cx, obj, proto, &JsClass, \
> 		c::JSConstructor, args,\
> 		NULL, c::JsMethods,\
> 		NULL, NULL);\
> 		JS_DefineProperties(cx, newObj, c::JsProperties);\
> 		return newObj;\
> 	}\
> 	JSObject *c::JSInitGlobal(JSContext *cx, JSObject *obj, const char* Name) \
> 	{ \
> 		if(!Name) Name = #c; \
> 		JSObject *ClassObject;\
> 		ClassObject = JS_DefineObject(cx, obj, Name, &JsClass, NULL, 0);\
> 		if(!ClassObject) { fprintf(stderr, "klassenobjekt nicht initialisiert");  return NULL; }\
> 		if(!JS_DefineFunctions(cx, ClassObject, c::JsMethods)) { fprintf(stderr, "funktionen nicht initialisiert");  return NULL; }\
> 		if(!JS_DefineProperties(cx, ClassObject, c::JsProperties)) { fprintf(stderr, "eigenschaften nicht initialisiert");  return NULL; }\
> 		return ClassObject ; \
> 	}
> 
> #define IMPLEMENT_JSDESTRUCTOR(c)\
> void c::JSDestructor(JSContext *cx, JSObject *obj)\
> {\
> 	c* pThis = (c*)JS_GetPrivate(cx, obj);\
> 	if(pThis) delete pThis;\
> 	pThis = NULL;\
> }
> 
> #define IMPLEMENT_JSCONSTRUCTOR(c)\
> JSBool c::JSConstructor(JSContext *cx, JSObject *obj, uintN argc,  jsval *argv, jsval *rval)\
> {\
> 	c* pThis = new c();\
> 	JS_SetPrivate(cx, obj, (void*)pThis);\
> 	return JS_TRUE;\
> }
> 
> 
> #define IMPLEMENT_JSCONSTRUCTOR_ARGS1(c,arg1)\
> JSBool c::JSConstructor(JSContext *cx, JSObject *obj, uintN argc,  jsval *argv, jsval *rval)\
> {\
> 	c* pThis = new c(arg1);\
> 	JS_SetPrivate(cx, obj, (void*)pThis);\
> 	return JS_TRUE;\
> }
> 
> #define IMPLEMENT_JSCONSTRUCTOR_ARGS2(c,arg1,arg2)\
> JSBool c::JSConstructor(JSContext *cx, JSObject *obj, uintN argc,  jsval *argv, jsval *rval)\
> {\
> 	c* pThis = new c(arg1,arg2);\
> 	JS_SetPrivate(cx, obj, (void*)pThis);\
> 	return JS_TRUE;\
> }
> 
> 
> 
> #define IMPLEMENT_JSCLASS(c) \
> JSClass c::JsClass = \
> {\
> 	#c, JSCLASS_HAS_PRIVATE,\
> 		JS_PropertyStub, JS_PropertyStub,\
> 		c::JSGetProperty, c::JSSetProperty,\
> 		JS_EnumerateStub, JS_ResolveStub, \
> 		JS_ConvertStub, c::JSDestructor\
> };
> 
> #define DEFINE_PROPERTIES(c) JSPropertySpec c::JsProperties[] = 
> #define DEFINE_OBJECTMETHODS(c) JSFunctionSpec c::JsMethods[] = 
> 
> #define DEFINE_METHOD(f, nArgs)    { #f, f, nArgs, 0, 0 },
> 
> #define DEFINE_END { 0 }
> 
> #define METHOD_DEKLARATION(f) static JSBool f##(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
> 
> #define METHOD_IMPLEMENTATION(c, f) \
> JSBool c::f(JSContext *cx, JSObject *obj, uintN argc, \
>                                        jsval *argv, jsval *value)\
>    {\
> 	c* pThis = (c*)JS_GetPrivate(cx, obj); \
> 	const char* FuncName = #f;\
> {
>      
> 
> #define IMPLEMENT_GET_PROPERTIES(c)\
> JSBool c::JSGetProperty(JSContext *cx, JSObject *obj, jsval id, jsval *value)\
> {\
> 	if (!JSVAL_IS_INT(id)) return JS_TRUE;\
> 	c* pThis = (c*)JS_GetPrivate(cx, obj);\
> 	switch(JSVAL_TO_INT(id))\
>     {
> 
> #define IMPLEMENT_SET_PROPERTIES(c)\
> JSBool c::JSSetProperty(JSContext *cx, JSObject *obj, jsval id, jsval *value)\
> {\
> 	if (!JSVAL_IS_INT(id)) return JS_TRUE;\
> 	c* pThis = (c*)JS_GetPrivate(cx, obj);\
> 	switch(JSVAL_TO_INT(id))\
>     {
> 	
> 
> #define END_IMPLEMENT 	}	return JS_TRUE; }
> 
> 
> #define PROPERTY(p) case p: {
> #define ENDPROPERTY } break;
> 
> #define RETURN_VALUE_INT(v) *value = INT_TO_JSVAL(v);
> #define RETURN_VALUE_DOUBLE(v) JS_NewDoubleValue(cx,v, value);
> 
> 
> #define CHECKARGSCOUNT(nArgs)\
> 		if(argc != nArgs)\
> 		{\
> 			JS_ReportError(cx, "%s needs exactly %i aguments", FuncName, nArgs);\
> 			return false;\
> 		}



source implementation:
> 
> int32 Jsval_AsInt(JSContext *cx, jsval v)
> {
> 	int32 Value=0;
> 	JS_ValueToInt32(cx, v, &Value);
> 	return Value;
> }
> 
> jsdouble Jsval_AsDouble(JSContext *cx, jsval v)
> {
> 	jsdouble  Value=0;
> 	JS_ValueToNumber(cx, v, &Value);
> 	return Value;
> }



example:

> #include "JsHelper.h"
> 
> class DoSomething
> {
> public:
> 	DoSomething(int Arg1, int Arg2);
> 	virtual ~Schalter();
> 	DEFINE_JSCLASS;
> 	METHOD_DEKLARATION(Save);
> 	void setstate(int state); int getstate(); 
> protected:
> 	int m_nAdress;
> };

> IMPLEMENT_JSINIT_ARGS(DoSomething,2);
> IMPLEMENT_JSCONSTRUCTOR_ARGS2(DoSomething, JSVAL_AS_INT(argv[0]), JSVAL_AS_INT(argv[1])); 
> 
> IMPLEMENT_JSCLASS(DoSomething)
> IMPLEMENT_JSDESTRUCTOR(DoSomething);
> 
> 

> DEFINE_OBJECTMETHODS(DoSomething)
> {
> 	DEFINE_METHOD(Save, 0)	
> 	DEFINE_END
> }; 

> 
> DEFINE_PROPERTIES(DoSomething)
> { 
>     { "state", 1, JSPROP_ENUMERATE }, 
> 	DEFINE_END
> };
> 
> IMPLEMENT_SET_PROPERTIES(DoSomething)
> 	PROPERTY(1)
> 	pThis->setstate(JSVAL_AS_INT(*value));
> 	ENDPROPERTY
> 
> END_IMPLEMENT;
> 
> 
> IMPLEMENT_GET_PROPERTIES(DoSomething)
> PROPERTY(1)
> 	RETURN_VALUE_INT(pThis->getstate());
> ENDPROPERTY
> END_IMPLEMENT;

> METHOD_IMPLEMENTATION(DoSomething, Save)
> {
> 	pThis->save();
> 	return JS_TRUE;
> }
> END_IMPLEMENT;


please send me a short message if you use parts of it, you'll get more 
examples and updates :-)

sincerely,
stefan noll

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