1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef CHROME_RENDERER_EXTENSIONS_MODULE_SYSTEM_H_
6 #define CHROME_RENDERER_EXTENSIONS_MODULE_SYSTEM_H_
8 #include "base/compiler_specific.h"
9 #include "base/memory/linked_ptr.h"
10 #include "base/memory/scoped_ptr.h"
11 #include "chrome/renderer/extensions/native_handler.h"
12 #include "chrome/renderer/extensions/object_backed_native_handler.h"
13 #include "v8/include/v8.h"
20 namespace extensions {
22 class ChromeV8Context;
24 // A module system for JS similar to node.js' require() function.
25 // Each module has three variables in the global scope:
26 // - exports, an object returned to dependencies who require() this
28 // - require, a function that takes a module name as an argument and returns
29 // that module's exports object.
30 // - requireNative, a function that takes the name of a registered
31 // NativeHandler and returns an object that contains the functions the
32 // NativeHandler defines.
34 // Each module in a ModuleSystem is executed at most once and its exports
37 // Note that a ModuleSystem must be used only in conjunction with a single
39 // TODO(koz): Rename this to JavaScriptModuleSystem.
40 class ModuleSystem : public ObjectBackedNativeHandler {
44 virtual ~SourceMap() {}
45 virtual v8::Handle<v8::Value> GetSource(v8::Isolate* isolate,
46 const std::string& name) = 0;
47 virtual bool Contains(const std::string& name) = 0;
50 class ExceptionHandler {
52 virtual ~ExceptionHandler() {}
53 virtual void HandleUncaughtException(const v8::TryCatch& try_catch) = 0;
56 // Formats |try_catch| as a nice string.
57 std::string CreateExceptionString(const v8::TryCatch& try_catch);
60 // Enables native bindings for the duration of its lifetime.
61 class NativesEnabledScope {
63 explicit NativesEnabledScope(ModuleSystem* module_system);
64 ~NativesEnabledScope();
67 ModuleSystem* module_system_;
68 DISALLOW_COPY_AND_ASSIGN(NativesEnabledScope);
71 // |source_map| is a weak pointer.
72 ModuleSystem(ChromeV8Context* context, SourceMap* source_map);
73 virtual ~ModuleSystem();
75 // Require the specified module. This is the equivalent of calling
76 // require('module_name') from the loaded JS files.
77 v8::Handle<v8::Value> Require(const std::string& module_name);
78 void Require(const v8::FunctionCallbackInfo<v8::Value>& args);
80 // Run |code| in the current context with the name |name| used for stack
82 v8::Handle<v8::Value> RunString(v8::Handle<v8::String> code,
83 v8::Handle<v8::String> name);
85 // Calls the specified method exported by the specified module. This is
86 // equivalent to calling require('module_name').method_name() from JS.
87 v8::Local<v8::Value> CallModuleMethod(const std::string& module_name,
88 const std::string& method_name);
89 v8::Local<v8::Value> CallModuleMethod(
90 const std::string& module_name,
91 const std::string& method_name,
92 std::vector<v8::Handle<v8::Value> >* args);
93 v8::Local<v8::Value> CallModuleMethod(
94 const std::string& module_name,
95 const std::string& method_name,
97 v8::Handle<v8::Value> argv[]);
99 // Register |native_handler| as a potential target for requireNative(), so
100 // calls to requireNative(|name|) from JS will return a new object created by
102 void RegisterNativeHandler(const std::string& name,
103 scoped_ptr<NativeHandler> native_handler);
105 // Causes requireNative(|name|) to look for its module in |source_map_|
106 // instead of using a registered native handler. This can be used in unit
107 // tests to mock out native modules.
108 void OverrideNativeHandlerForTest(const std::string& name);
110 // Executes |code| in the current context with |name| as the filename.
111 void RunString(const std::string& code, const std::string& name);
113 // Make |object|.|field| lazily evaluate to the result of
114 // require(|module_name|)[|module_field|].
116 // TODO(kalman): All targets for this method are ObjectBackedNativeHandlers,
117 // move this logic into those classes (in fact, the chrome
118 // object is the only client, only that needs to implement it).
119 void SetLazyField(v8::Handle<v8::Object> object,
120 const std::string& field,
121 const std::string& module_name,
122 const std::string& module_field);
124 void SetLazyField(v8::Handle<v8::Object> object,
125 const std::string& field,
126 const std::string& module_name,
127 const std::string& module_field,
128 v8::AccessorGetterCallback getter);
130 // Make |object|.|field| lazily evaluate to the result of
131 // requireNative(|module_name|)[|module_field|].
132 // TODO(kalman): Same as above.
133 void SetNativeLazyField(v8::Handle<v8::Object> object,
134 const std::string& field,
135 const std::string& module_name,
136 const std::string& module_field);
138 // Passes exceptions to |handler| rather than console::Fatal.
139 void SetExceptionHandlerForTest(scoped_ptr<ExceptionHandler> handler) {
140 exception_handler_ = handler.Pass();
144 friend class ChromeV8Context;
145 virtual void Invalidate() OVERRIDE;
148 typedef std::map<std::string, linked_ptr<NativeHandler> > NativeHandlerMap;
150 // Retrieves the lazily defined field specified by |property|.
151 static void LazyFieldGetter(v8::Local<v8::String> property,
152 const v8::PropertyCallbackInfo<v8::Value>& info);
153 // Retrieves the lazily defined field specified by |property| on a native
155 static void NativeLazyFieldGetter(
156 v8::Local<v8::String> property,
157 const v8::PropertyCallbackInfo<v8::Value>& info);
159 // Called when an exception is thrown but not caught.
160 void HandleException(const v8::TryCatch& try_catch);
162 // Ensure that require_ has been evaluated from require.js.
163 void EnsureRequireLoaded();
165 void RequireForJs(const v8::FunctionCallbackInfo<v8::Value>& args);
166 v8::Local<v8::Value> RequireForJsInner(v8::Handle<v8::String> module_name);
168 typedef v8::Handle<v8::Value> (ModuleSystem::*RequireFunction)(
170 // Base implementation of a LazyFieldGetter which uses |require_fn| to require
172 static void LazyFieldGetterInner(
173 v8::Local<v8::String> property,
174 const v8::PropertyCallbackInfo<v8::Value>& info,
175 RequireFunction require_function);
177 // Return the named source file stored in the source map.
178 // |args[0]| - the name of a source file in source_map_.
179 v8::Handle<v8::Value> GetSource(const std::string& module_name);
181 // Return an object that contains the native methods defined by the named
183 // |args[0]| - the name of a native handler object.
184 v8::Handle<v8::Value> RequireNativeFromString(const std::string& native_name);
185 void RequireNative(const v8::FunctionCallbackInfo<v8::Value>& args);
187 // Wraps |source| in a (function(require, requireNative, exports) {...}).
188 v8::Handle<v8::String> WrapSource(v8::Handle<v8::String> source);
190 // NativeHandler implementation which returns the private area of an Object.
191 void Private(const v8::FunctionCallbackInfo<v8::Value>& args);
193 // NativeHandler implementation which returns a function wrapper for a
194 // provided function.
195 void CreateFunctionWrapper(const v8::FunctionCallbackInfo<v8::Value>& args);
197 ChromeV8Context* context_;
199 // A map from module names to the JS source for that module. GetSource()
200 // performs a lookup on this map.
201 SourceMap* source_map_;
203 // A map from native handler names to native handlers.
204 NativeHandlerMap native_handler_map_;
206 // When 0, natives are disabled, otherwise indicates how many callers have
207 // pinned natives as enabled.
208 int natives_enabled_;
210 // Called when an exception is thrown but not caught in JS. Overridable by
212 scoped_ptr<ExceptionHandler> exception_handler_;
214 std::set<std::string> overridden_native_handlers_;
216 DISALLOW_COPY_AND_ASSIGN(ModuleSystem);
219 } // namespace extensions
221 #endif // CHROME_RENDERER_EXTENSIONS_MODULE_SYSTEM_H_