v8::FunctionTemplate Class Reference

#include <v8.h>

Inheritance diagram for v8::FunctionTemplate:

Public Member Functions
	V8_DEPRECATED ("Use maybe version", Local< Function > GetFunction())
V8_WARN_UNUSED_RESULT MaybeLocal< Function >	GetFunction (Local< Context > context)
V8_WARN_UNUSED_RESULT MaybeLocal< Object >	NewRemoteInstance ()
void	SetCallHandler (FunctionCallback callback, Local< Value > data=Local< Value >(), SideEffectType side_effect_type=SideEffectType::kHasSideEffect)
void	SetLength (int length)
Local< ObjectTemplate >	InstanceTemplate ()
void	Inherit (Local< FunctionTemplate > parent)
Local< ObjectTemplate >	PrototypeTemplate ()
void	SetPrototypeProviderTemplate (Local< FunctionTemplate > prototype_provider)
void	SetClassName (Local< String > name)
void	SetAcceptAnyReceiver (bool value)
void	SetHiddenPrototype (bool value)
void	ReadOnlyPrototype ()
void	RemovePrototype ()
bool	HasInstance (Local< Value > object)
Public Member Functions inherited from v8::Template
void	Set (Local< Name > name, Local< Data > value, PropertyAttribute attributes=None)
void	SetPrivate (Local< Private > name, Local< Data > value, PropertyAttribute attributes=None)
V8_INLINE void	Set (Isolate *isolate, const char *name, Local< Data > value)
void	SetAccessorProperty (Local< Name > name, Local< FunctionTemplate > getter=Local< FunctionTemplate >(), Local< FunctionTemplate > setter=Local< FunctionTemplate >(), PropertyAttribute attribute=None, AccessControl settings=DEFAULT)
void	SetNativeDataProperty (Local< String > name, AccessorGetterCallback getter, AccessorSetterCallback setter=nullptr, Local< Value > data=Local< Value >(), PropertyAttribute attribute=None, Local< AccessorSignature > signature=Local< AccessorSignature >(), AccessControl settings=DEFAULT, SideEffectType getter_side_effect_type=SideEffectType::kHasSideEffect, SideEffectType setter_side_effect_type=SideEffectType::kHasSideEffect)
void	SetNativeDataProperty (Local< Name > name, AccessorNameGetterCallback getter, AccessorNameSetterCallback setter=nullptr, Local< Value > data=Local< Value >(), PropertyAttribute attribute=None, Local< AccessorSignature > signature=Local< AccessorSignature >(), AccessControl settings=DEFAULT, SideEffectType getter_side_effect_type=SideEffectType::kHasSideEffect, SideEffectType setter_side_effect_type=SideEffectType::kHasSideEffect)
void	SetLazyDataProperty (Local< Name > name, AccessorNameGetterCallback getter, Local< Value > data=Local< Value >(), PropertyAttribute attribute=None, SideEffectType getter_side_effect_type=SideEffectType::kHasSideEffect, SideEffectType setter_side_effect_type=SideEffectType::kHasSideEffect)
void	SetIntrinsicDataProperty (Local< Name > name, Intrinsic intrinsic, PropertyAttribute attribute=None)

Static Public Member Functions
static Local< FunctionTemplate >	New (Isolate *isolate, FunctionCallback callback=nullptr, Local< Value > data=Local< Value >(), Local< Signature > signature=Local< Signature >(), int length=0, ConstructorBehavior behavior=ConstructorBehavior::kAllow, SideEffectType side_effect_type=SideEffectType::kHasSideEffect)
static MaybeLocal< FunctionTemplate >	FromSnapshot (Isolate *isolate, size_t index)
static Local< FunctionTemplate >	NewWithCache (Isolate *isolate, FunctionCallback callback, Local< Private > cache_property, Local< Value > data=Local< Value >(), Local< Signature > signature=Local< Signature >(), int length=0, SideEffectType side_effect_type=SideEffectType::kHasSideEffect)
static V8_INLINE FunctionTemplate *	Cast (Data *data)

Friends
class	Context
class	ObjectTemplate

Detailed Description

A FunctionTemplate is used to create functions at runtime. There can only be one function created from a FunctionTemplate in a context. The lifetime of the created function is equal to the lifetime of the context. So in case the embedder needs to create temporary functions that can be collected using Scripts is preferred.

Any modification of a FunctionTemplate after first instantiation will trigger a crash.

A FunctionTemplate can have properties, these properties are added to the function object when it is created.

A FunctionTemplate has a corresponding instance template which is used to create object instances when the function is used as a constructor. Properties added to the instance template are added to each object instance.

A FunctionTemplate can have a prototype template. The prototype template is used to create the prototype object of the function.

The following example shows how to use a FunctionTemplate:

v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(isolate);
t->Set(isolate, "func_property", v8::Number::New(isolate, 1));

v8::Local<v8::Template> proto_t = t->PrototypeTemplate();
proto_t->Set(isolate,
             "proto_method",
             v8::FunctionTemplate::New(isolate, InvokeCallback));
proto_t->Set(isolate, "proto_const", v8::Number::New(isolate, 2));

v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
instance_t->SetAccessor(String::NewFromUtf8(isolate, "instance_accessor"),
                        InstanceAccessorCallback);
instance_t->SetHandler(
    NamedPropertyHandlerConfiguration(PropertyHandlerCallback));
instance_t->Set(String::NewFromUtf8(isolate, "instance_property"),
                Number::New(isolate, 3));

v8::Local<v8::Function> function = t->GetFunction();
v8::Local<v8::Object> instance = function->NewInstance();

Let's use "function" as the JS variable name of the function object and "instance" for the instance object created above. The function and the instance will have the following properties:

func_property in function == true;
function.func_property == 1;

function.prototype.proto_method() invokes 'InvokeCallback'
function.prototype.proto_const == 2;

instance instanceof function == true;
instance.instance_accessor calls 'InstanceAccessorCallback'
instance.instance_property == 3;

A FunctionTemplate can inherit from another one by calling the FunctionTemplate::Inherit method. The following graph illustrates the semantics of inheritance:

FunctionTemplate Parent  -> Parent() . prototype -> { }
  ^                                                  ^
  | Inherit(Parent)                                  | .__proto__
  |                                                  |
FunctionTemplate Child   -> Child()  . prototype -> { }

A FunctionTemplate 'Child' inherits from 'Parent', the prototype object of the Child() function has proto pointing to the Parent() function's prototype object. An instance of the Child function has all properties on Parent's instance templates.

Let Parent be the FunctionTemplate initialized in the previous section and create a Child FunctionTemplate by:

Local<FunctionTemplate> parent = t;
Local<FunctionTemplate> child = FunctionTemplate::New();
child->Inherit(parent);

Local<Function> child_function = child->GetFunction();
Local<Object> child_instance = child_function->NewInstance();

The Child function and Child instance will have the following properties:

child_func.prototype.__proto__ == function.prototype;
child_instance.instance_accessor calls 'InstanceAccessorCallback'
child_instance.instance_property == 3;

Definition at line 5718 of file v8.h.

Member Function Documentation

FromSnapshot()

MaybeLocal< FunctionTemplate > v8::FunctionTemplate::FromSnapshot ( Isolate *  isolate, size_t  index  )

static

Get a template included in the snapshot by index.

Definition at line 1432 of file api.cc.

HasInstance()

bool v8::FunctionTemplate::HasInstance

(

Local< Value >

object

)

Returns true if the given object is an instance of this function template.

Definition at line 6401 of file api.cc.

Inherit()

void v8::FunctionTemplate::Inherit

(

v8::Local< FunctionTemplate >

value

)

Causes the function template to inherit from a parent function template. This means the function's prototype.__proto__ is set to the parent function's prototype.

Definition at line 1374 of file api.cc.

InstanceTemplate()

Local< ObjectTemplate > v8::FunctionTemplate::InstanceTemplate

(

)

Get the InstanceTemplate.

Definition at line 1538 of file api.cc.

New()

Local< FunctionTemplate > v8::FunctionTemplate::New ( Isolate *  isolate, FunctionCallback  callback = nullptr, v8::Local< Value >  data = Local<Value>(), v8::Local< Signature >  signature = Local<Signature>(), int  length = 0, ConstructorBehavior  behavior = ConstructorBehavior::kAllow, SideEffectType  side_effect_type = SideEffectType::kHasSideEffect  )

static

Creates a function template.

Definition at line 1417 of file api.cc.

NewRemoteInstance()

MaybeLocal< v8::Object > v8::FunctionTemplate::NewRemoteInstance

(

)

Similar to Context::NewRemoteContext, this creates an instance that isn't backed by an actual object.

The InstanceTemplate of this FunctionTemplate must have access checks with handlers installed.

Definition at line 6374 of file api.cc.

NewWithCache()

Local< FunctionTemplate > v8::FunctionTemplate::NewWithCache ( Isolate *  isolate, FunctionCallback  callback, Local< Private >  cache_property, Local< Value >  data = Local<Value>(), Local< Signature >  signature = Local<Signature>(), int  length = 0, SideEffectType  side_effect_type = SideEffectType::kHasSideEffect  )

static

Creates a function template backed/cached by a private property.

Definition at line 1447 of file api.cc.

PrototypeTemplate()

Local< ObjectTemplate > v8::FunctionTemplate::PrototypeTemplate

(

)

A PrototypeTemplate is the template used to create the prototype object of the function created by this template.

Definition at line 1340 of file api.cc.

ReadOnlyPrototype()

void v8::FunctionTemplate::ReadOnlyPrototype

(

)

Sets the ReadOnly flag in the attributes of the 'prototype' property of functions created from this FunctionTemplate to true.

Definition at line 1595 of file api.cc.

RemovePrototype()

void v8::FunctionTemplate::RemovePrototype

(

)

Removes the prototype property from functions created from this FunctionTemplate.

Definition at line 1604 of file api.cc.

SetAcceptAnyReceiver()

void v8::FunctionTemplate::SetAcceptAnyReceiver

(

bool

value

)

When set to true, no access check will be performed on the receiver of a function call. Currently defaults to true, but this is subject to change.

Definition at line 1577 of file api.cc.

SetCallHandler()

void v8::FunctionTemplate::SetCallHandler	(	FunctionCallback	callback,
		v8::Local< Value >	data = Local<Value>(),
		SideEffectType	side_effect_type = SideEffectType::kHasSideEffect
	)

Set the call-handler callback for a FunctionTemplate. This callback is called whenever the function created from this FunctionTemplate is called.

Definition at line 1475 of file api.cc.

SetClassName()

void v8::FunctionTemplate::SetClassName

(

Local< String >

name

)

Set the class name of the FunctionTemplate. This is used for printing objects created with the function created from the FunctionTemplate as its constructor.

Definition at line 1568 of file api.cc.

SetHiddenPrototype()

void v8::FunctionTemplate::SetHiddenPrototype

(

bool

value

)

Determines whether the proto accessor ignores instances of the function template. If instances of the function template are ignored, proto skips all instances and instead returns the next object in the prototype chain.

Call with a value of true to make the proto accessor ignore instances of the function template. Call with a value of false to make the proto accessor not ignore instances of the function template. By default, instances of a function template are not ignored.

Definition at line 1586 of file api.cc.

SetLength()

void v8::FunctionTemplate::SetLength

(

int

length

)

Set the predefined length property for the FunctionTemplate.

Definition at line 1559 of file api.cc.

SetPrototypeProviderTemplate()

void v8::FunctionTemplate::SetPrototypeProviderTemplate

(

Local< FunctionTemplate >

prototype_provider

)

A PrototypeProviderTemplate is another function template whose prototype property is used for this template. This is mutually exclusive with setting a prototype template indirectly by calling PrototypeTemplate() or using Inherit().

Definition at line 1355 of file api.cc.

V8_DEPRECATED()

v8::FunctionTemplate::V8_DEPRECATED	(	"Use maybe version"	,
		Local< Function >	GetFunction()
	)

Returns the unique function instance in the current execution context.

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The documentation for this class was generated from the following files:

• v8/include/v8.h
• v8/src/api.cc