From 31639299902fb2cbfe80cff66377db9748c4ecee Mon Sep 17 00:00:00 2001 From: Andreas Kling Date: Sun, 15 Mar 2020 18:15:44 +0100 Subject: LibJS: Add a mechanism for callback-based object properties This patch adds NativeProperty, which can be used to implement object properties that have C++ getters and/or setters. Use this to move String.prototype.length to its correct place. :^) --- Libraries/LibJS/Makefile | 1 + Libraries/LibJS/NativeProperty.cpp | 56 +++++++++++++++++++++++++++++++++++++ Libraries/LibJS/NativeProperty.h | 50 +++++++++++++++++++++++++++++++++ Libraries/LibJS/Object.cpp | 11 +++++++- Libraries/LibJS/Object.h | 2 ++ Libraries/LibJS/StringObject.cpp | 1 - Libraries/LibJS/StringPrototype.cpp | 6 ++++ 7 files changed, 125 insertions(+), 2 deletions(-) create mode 100644 Libraries/LibJS/NativeProperty.cpp create mode 100644 Libraries/LibJS/NativeProperty.h (limited to 'Libraries') diff --git a/Libraries/LibJS/Makefile b/Libraries/LibJS/Makefile index f067594753..019c49d974 100644 --- a/Libraries/LibJS/Makefile +++ b/Libraries/LibJS/Makefile @@ -8,6 +8,7 @@ OBJS = \ Interpreter.o \ Lexer.o \ NativeFunction.o \ + NativeProperty.o \ Object.o \ ObjectPrototype.o \ Parser.o \ diff --git a/Libraries/LibJS/NativeProperty.cpp b/Libraries/LibJS/NativeProperty.cpp new file mode 100644 index 0000000000..e0db919ce8 --- /dev/null +++ b/Libraries/LibJS/NativeProperty.cpp @@ -0,0 +1,56 @@ +/* + * Copyright (c) 2020, Andreas Kling + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include + +namespace JS { + +NativeProperty::NativeProperty(AK::Function getter, AK::Function setter) + : m_getter(move(getter)) + , m_setter(move(setter)) +{ +} + +NativeProperty::~NativeProperty() +{ +} + +Value NativeProperty::get(Object* object) const +{ + if (!m_getter) + return js_undefined(); + return m_getter(object); +} + +void NativeProperty::set(Object* object, Value value) +{ + if (!m_setter) + return; + m_setter(object, move(value)); +} + +} diff --git a/Libraries/LibJS/NativeProperty.h b/Libraries/LibJS/NativeProperty.h new file mode 100644 index 0000000000..6406ecfb20 --- /dev/null +++ b/Libraries/LibJS/NativeProperty.h @@ -0,0 +1,50 @@ +/* + * Copyright (c) 2020, Andreas Kling + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#pragma once + +#include +#include + +namespace JS { + +class NativeProperty final : public Object { +public: + NativeProperty(AK::Function getter, AK::Function setter); + virtual ~NativeProperty() override; + + Value get(Object*) const; + void set(Object*, Value); + +private: + virtual bool is_native_property() const override { return true; } + virtual const char* class_name() const override { return "NativeProperty"; } + + AK::Function m_getter; + AK::Function m_setter; +}; + +} diff --git a/Libraries/LibJS/Object.cpp b/Libraries/LibJS/Object.cpp index 5f89aa6941..d9e7700685 100644 --- a/Libraries/LibJS/Object.cpp +++ b/Libraries/LibJS/Object.cpp @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -47,8 +48,11 @@ Value Object::get(String property_name) const const Object* object = this; while (object) { auto value = object->m_properties.get(property_name); - if (value.has_value()) + if (value.has_value()) { + if (value.value().is_object() && value.value().as_object()->is_native_property()) + return static_cast(value.value().as_object())->get(const_cast(this)); return value.value(); + } object = object->prototype(); } return js_undefined(); @@ -64,6 +68,11 @@ void Object::put_native_function(String property_name, AK::Function(move(native_function))); } +void Object::put_native_property(String property_name, AK::Function getter, AK::Function setter) +{ + put(property_name, heap().allocate(move(getter), move(setter))); +} + void Object::visit_children(Cell::Visitor& visitor) { Cell::visit_children(visitor); diff --git a/Libraries/LibJS/Object.h b/Libraries/LibJS/Object.h index 293e843f01..43bd0ae53b 100644 --- a/Libraries/LibJS/Object.h +++ b/Libraries/LibJS/Object.h @@ -42,10 +42,12 @@ public: void put(String property_name, Value); void put_native_function(String property_name, AK::Function)>); + void put_native_property(String property_name, AK::Function getter, AK::Function setter); virtual bool is_function() const { return false; } virtual bool is_native_function() const { return false; } virtual bool is_string_object() const { return false; } + virtual bool is_native_property() const { return false; } virtual const char* class_name() const override { return "Object"; } virtual void visit_children(Cell::Visitor&) override; diff --git a/Libraries/LibJS/StringObject.cpp b/Libraries/LibJS/StringObject.cpp index 6eb09ff4f2..607d7f6917 100644 --- a/Libraries/LibJS/StringObject.cpp +++ b/Libraries/LibJS/StringObject.cpp @@ -37,7 +37,6 @@ StringObject::StringObject(PrimitiveString* string) : m_string(string) { set_prototype(interpreter().string_prototype()); - put("length", Value(static_cast(m_string->string().length()))); } StringObject::~StringObject() diff --git a/Libraries/LibJS/StringPrototype.cpp b/Libraries/LibJS/StringPrototype.cpp index 3d1f50ede6..a32de5504a 100644 --- a/Libraries/LibJS/StringPrototype.cpp +++ b/Libraries/LibJS/StringPrototype.cpp @@ -36,6 +36,12 @@ namespace JS { StringPrototype::StringPrototype() { + put_native_property( + "length", [](Object* object) { + ASSERT(object->is_string_object()); + return Value((i32) static_cast(object)->primitive_string()->string().length()); + }, + nullptr); put_native_function("charAt", [](Interpreter& interpreter, Vector arguments) -> Value { i32 index = 0; if (!arguments.is_empty()) -- cgit v1.2.3