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foreach callback and little more on the readme
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Bradley Meck committed May 27, 2010
1 parent bfd2d23 commit 6e773cb
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22 changes: 18 additions & 4 deletions README.TXT
View file
@@ -1,10 +1,22 @@
#node-watchable

##exports
* Watchable(onGet,onSet)
* Watchable(onGet,onSet,onForeach)

Supplies getter and setter callbacks across all the properties along with a for(x in y) callback that returns the list
Callback's can use the _this_ object in order to act normally without reinvoking themselves.

** Value onGet(String propertyName, Value value, hadAlready)

Returns the value at a specific index
** Value onSet(String propertyName, Value oldValue, Value value, hadAlready)

Returns the value to save at a specific index
** Array onForeach()

Returns an array containing all the index keys for this object


Supplies getter and setter callbacks across all the properties
Currently both callbacks are required

##example
Code
Expand Down Expand Up @@ -32,4 +44,6 @@ Output

##uses
1. Debugging - Show what is being accessed / set
2. False natives - refuse to allow properties to be set / got beyond a specified few
2. False natives - refuse to allow properties to be set / got beyond a specified few
3. Dynamic programming - Fib[3] could compute Fib[1] and Fib[2]
4. Index based getters / setters - Fib[0] cannot have a getter set normally because it is a number not string based index (all non-number non-undefined values become string based).
183 changes: 135 additions & 48 deletions overload.cc
View file
Expand Up @@ -20,7 +20,15 @@ Handle<Value> WatchableNamedPropertyGetter(
) {
HandleScope scope;
//Grab the value of the property
Handle<Object> holder=info.Holder();
Handle<Object> holder = info.Holder();
Handle<Object> map = Handle<Object>::Cast(
holder->GetInternalField(0)
);
//Default
Handle<Value> data = holder->GetInternalField(1);
if(data->IsNull()) {
return scope.Close(map->Get(property));
}
Handle<Value> value;
Handle<Value> had_value;

Expand All @@ -37,7 +45,6 @@ Handle<Value> WatchableNamedPropertyGetter(
Handle<Value> values[3] = {property,value,had_value};

//Grab function and call (property,value)
Handle<Value> data = holder->GetInternalField(1);
Handle<Function> callback = Handle<Function>::Cast(data);
Handle<Value> new_value = callback->Call(info.Holder(),3,values);

Expand All @@ -52,7 +59,8 @@ Handle<Value> WatchableNamedPropertySetter(
) {
HandleScope scope;
//Grab the value of the property
Handle<Object> holder = Handle<Object>::Cast(
Handle<Object> holder = info.Holder();
Handle<Object> map = Handle<Object>::Cast(
holder->GetInternalField(0)
);
Handle<Value> old_value;
Expand All @@ -66,14 +74,21 @@ Handle<Value> WatchableNamedPropertySetter(
old_value = Undefined();
had_value = False();
}
//Default
Handle<Value> data = holder->GetInternalField(2);
if(data->IsNull()) {
return scope.Close(map->Set(property,value)
?value
:old_value
);
}

//Set up arguments
Handle<Value> values[4] = {property,old_value,value,had_value};

//Grab function and call (property,value)
Handle<Value> data = holder->GetInternalField(2);
Handle<Function> callback = Handle<Function>::Cast(data);
Handle<Value> new_value = callback->Call(Holder,4,values);
Handle<Value> new_value = callback->Call(holder,4,values);

holder->ForceSet(property,new_value);

Expand All @@ -86,26 +101,32 @@ Handle<Array> WatchableNamedPropertyEnumerator(
) {
HandleScope scope;
//Grab the value of the property
Handle<Object> holder = Handle<Object>::Cast(
Handle<Object> holder = info.Holder();
Handle<Object> map = Handle<Object>::Cast(
holder->GetInternalField(0)
);
//Default
Handle<Value> data = holder->GetInternalField(4);
if(data->IsNull()) {
return scope.Close(map->GetPropertyNames());
}
Handle<Value> old_value;
Handle<Value> had_value;

Handle<Array> names = holder->GetPropertyNames();

//Set up arguments
Handle<Value> values[4] = {property,old_value,value,had_value};
Handle<Value> values[0] = {};

//Grab function and call (property,value)
Handle<Value> data = holder->GetInternalField(2);
Handle<Function> callback = Handle<Function>::Cast(data);
Handle<Value> new_value = callback->Call(holder,4,values);

holder->ForceSet(property,new_value);
Handle<Value> new_value = callback->Call(holder,0,values);

//Return value is the return of the function call
return scope.Close(new_value);
if(new_value->IsArray()) {
return scope.Close(Handle<Array>::Cast(new_value));
}
else {
ThrowException(String::New("Callback must return an Array."));
return scope.Close(Array::New());
}
}

Handle<Value> WatchableIndexedPropertyGetter(
Expand All @@ -115,15 +136,21 @@ Handle<Value> WatchableIndexedPropertyGetter(
HandleScope scope;

//Grab the value
Handle<Object> holder = Handle<Object>::Cast(
Handle<Object> holder = info.Holder();
Handle<Object> map = Handle<Object>::Cast(
holder->GetInternalField(0)
);
//Default
Handle<Value> data = holder->GetInternalField(1);
if(data->IsNull()) {
return scope.Close(map->Get(index));
}
Handle<Number> property = Number::New(index);
Handle<Value> value;
Handle<Value> had_value;

if( holder->Has(index) ) {
value = holder->Get(index);
value = map->Get(index);
had_value = True();
}
else {
Expand All @@ -134,7 +161,6 @@ Handle<Value> WatchableIndexedPropertyGetter(
Handle<Value> values[3] = {property,value,had_value};

//Grab function and call (property,value)
Handle<Value> data = holder->GetInternalField(1);
Handle<Function> callback = Handle<Function>::Cast(data);
Handle<Value> new_value = callback->Call(holder,3,values);

Expand All @@ -148,82 +174,143 @@ Handle<Value> WatchableIndexedPropertySetter(
, const AccessorInfo& info
) {
HandleScope scope;

//Grab the value
Handle<Object> holder = Handle<Object>::Cast(
Handle<Object> holder = info.Holder();
Handle<Object> map = Handle<Object>::Cast(
holder->GetInternalField(0)
);
Handle<Number> property = Number::New(index);
Handle<Value> had_value;

Handle<Value> old_value;
if( holder->Has(index) ) {
old_value = holder->Get(index);
old_value = map->Get(index);
had_value = True();
}
else {
old_value = Undefined();
had_value = False();
}

//Default
Handle<Value> data = holder->GetInternalField(2);
if(data->IsNull()) {
return scope.Close(map->Set(index,value)
?value
:old_value
);
}
//Set up arguments
Handle<Value> values[4] = {property,old_value,value,had_value};

//Grab function and call (property,value)
Handle<Value> data = holder->GetInternalField(2);
Handle<Function> callback = Handle<Function>::Cast(data);
Handle<Value> new_value = callback->Call(holder,4,values);

holder->Set(index,new_value);
map->Set(index,new_value);

//Return value is the return of the function call
return scope.Close(new_value);
}
Handle<Array> WatchableIndexedPropertyEnumerator(
const AccessorInfo& info
) {
HandleScope scope;
//Grab the value
Handle<Object> holder = info.Holder();
Handle<Object> map = Handle<Object>::Cast(
holder->GetInternalField(0)
);
//Default
Handle<Value> data = holder->GetInternalField(2);
if(data->IsNull()) {
return scope.Close(map->GetPropertyNames());
}
//Set up arguments
Handle<Value> values[0];

//Grab function and call (property,value)
Handle<Function> callback = Handle<Function>::Cast(data);
Handle<Value> new_value = callback->Call(holder,0,values);

if(new_value->IsArray()) {
return scope.Close(Handle<Array>::Cast(new_value));
}
else {
ThrowException(String::New("Callback must return an Array."));
return scope.Close(Array::New());
}
}


Local<ObjectTemplate> object_template = ObjectTemplate::New();
Handle<Value> Watchable(const Arguments& args) {
HandleScope scope;
Handle<Value> getter = args[0];
//Check our arguments!
if(getter.IsEmpty() || getter->IsFunction()) {}
Handle<Value> getter = args[0];
if(getter->IsFunction()) {
//Do nothing
}
else if(getter->IsNull() || getter->IsUndefined()) {
getter = Null();
}
else {
return ThrowException(String::New("Getter callback must be a function"));
}
Handle<Value> setter = args[1];
if(setter.IsEmpty() || setter->IsFunction()) {}
if(setter->IsFunction()) {
//Do nothing
}
else if(setter->IsNull() || setter->IsUndefined()) {
setter = Null();
}
else {
return ThrowException(String::New("Getter callback must be a function"));
}
Handle<Object> watchable = object_template->NewInstance();
watchable->SetInternalField(0,Object::New());
watchable->SetInternalField(1,getter);
watchable->SetInternalField(2,setter);
return scope.Close(watchable);
}

extern "C" void init (Handle<Object> target)
{
HandleScope scope;
//Every one with a different callback needs a different template
//0 - Holder object - aka the real one
//1 - Getter
//2 - Setter
//3 - Query
//4 - Deleter
//5 - Enumerator
object_template->SetInternalFieldCount(5);
Handle<Value> enumerator = args[2];
if(enumerator->IsFunction()) {
//Do nothing
}
else if(enumerator->IsNull() || enumerator->IsUndefined()) {
enumerator = Null();
}
else {
return ThrowException(String::New("Getter callback must be a function"));
}
Local<ObjectTemplate> object_template = ObjectTemplate::New();
object_template->SetNamedPropertyHandler(
WatchableNamedPropertyGetter
,WatchableNamedPropertySetter
,WatchableNamedPropertySetter,0,0
// ,WatchableNamedPropertyQuery
// ,WatchableNamedPropertyDeleter
,WatchableNamedPropertyEnumerator
);
object_template->SetIndexedPropertyHandler(
WatchableIndexedPropertyGetter
,WatchableIndexedPropertySetter
,0,0,0
,0,0
//Is this ever used?
//,WatchableIndexedPropertyEnumerator
);
//Every one with a different callback needs a different template
//0 - Holder object - aka the real one
//1 - Getter
//2 - Setter
//3 - Query
//4 - Deleter
//5 - Enumerator
object_template->SetInternalFieldCount(5);
Handle<Object> watchable = object_template->NewInstance();
watchable->SetInternalField(0,Object::New());
watchable->SetInternalField(1,getter);
watchable->SetInternalField(2,setter);
watchable->SetInternalField(4,enumerator);
//printf("watchable created\n");
return scope.Close(watchable);
}

extern "C" void init (Handle<Object> target)
{
HandleScope scope;
//printf("init\n");
Local<FunctionTemplate> watchable_template = FunctionTemplate::New(Watchable);
Local<Function> watchable = watchable_template->GetFunction();
//Export
Expand Down

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