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1 /*
2  * Copyright (C) 2006, 2007, 2008, 2009 Google Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are
6  * met:
7  *
8  *     * Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *     * Redistributions in binary form must reproduce the above
11  * copyright notice, this list of conditions and the following disclaimer
12  * in the documentation and/or other materials provided with the
13  * distribution.
14  *     * Neither the name of Google Inc. nor the names of its
15  * contributors may be used to endorse or promote products derived from
16  * this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "config.h"
32 #include "V8LazyEventListener.h"
33 
34 #include "ContentSecurityPolicy.h"
35 #include "Frame.h"
36 #include "V8Binding.h"
37 #include "V8HiddenPropertyName.h"
38 #include "V8Proxy.h"
39 #include "WorldContextHandle.h"
40 
41 #include <wtf/StdLibExtras.h>
42 
43 namespace WebCore {
44 
V8LazyEventListener(const String & functionName,bool isSVGEvent,const String & code,const String sourceURL,const TextPosition0 & position,const WorldContextHandle & worldContext)45 V8LazyEventListener::V8LazyEventListener(const String& functionName, bool isSVGEvent, const String& code, const String sourceURL, const TextPosition0& position, const WorldContextHandle& worldContext)
46     : V8AbstractEventListener(true, worldContext)
47     , m_functionName(functionName)
48     , m_isSVGEvent(isSVGEvent)
49     , m_code(code)
50     , m_sourceURL(sourceURL)
51     , m_position(position)
52 {
53 }
54 
callListenerFunction(ScriptExecutionContext * context,v8::Handle<v8::Value> jsEvent,Event * event)55 v8::Local<v8::Value> V8LazyEventListener::callListenerFunction(ScriptExecutionContext* context, v8::Handle<v8::Value> jsEvent, Event* event)
56 {
57     v8::Local<v8::Object> listenerObject = getListenerObject(context);
58     if (listenerObject.IsEmpty())
59         return v8::Local<v8::Value>();
60 
61     v8::Local<v8::Function> handlerFunction = v8::Local<v8::Function>::Cast(listenerObject);
62     v8::Local<v8::Object> receiver = getReceiverObject(event);
63     if (handlerFunction.IsEmpty() || receiver.IsEmpty())
64         return v8::Local<v8::Value>();
65 
66     v8::Handle<v8::Value> parameters[1] = { jsEvent };
67 
68     if (V8Proxy* proxy = V8Proxy::retrieve(context))
69         return proxy->callFunction(handlerFunction, receiver, 1, parameters);
70 
71     return v8::Local<v8::Value>();
72 }
73 
V8LazyEventListenerToString(const v8::Arguments & args)74 static v8::Handle<v8::Value> V8LazyEventListenerToString(const v8::Arguments& args)
75 {
76     return args.Holder()->GetHiddenValue(V8HiddenPropertyName::toStringString());
77 }
78 
prepareListenerObject(ScriptExecutionContext * context)79 void V8LazyEventListener::prepareListenerObject(ScriptExecutionContext* context)
80 {
81     if (hasExistingListenerObject())
82         return;
83 
84     if (context->isDocument() && !static_cast<Document*>(context)->contentSecurityPolicy()->allowInlineEventHandlers())
85         return;
86 
87     v8::HandleScope handleScope;
88 
89     V8Proxy* proxy = V8Proxy::retrieve(context);
90     if (!proxy)
91         return;
92 
93     // Use the outer scope to hold context.
94     v8::Local<v8::Context> v8Context = worldContext().adjustedContext(proxy);
95     // Bail out if we cannot get the context.
96     if (v8Context.IsEmpty())
97         return;
98 
99     v8::Context::Scope scope(v8Context);
100 
101     // FIXME: cache the wrapper function.
102 
103     // Nodes other than the document object, when executing inline event handlers push document, form, and the target node on the scope chain.
104     // We do this by using 'with' statement.
105     // See chrome/fast/forms/form-action.html
106     //     chrome/fast/forms/selected-index-value.html
107     //     base/fast/overflow/onscroll-layer-self-destruct.html
108     //
109     // Don't use new lines so that lines in the modified handler
110     // have the same numbers as in the original code.
111     String code = "(function (evt) {" \
112             "with (this.ownerDocument ? this.ownerDocument : {}) {" \
113             "with (this.form ? this.form : {}) {" \
114             "with (this) {" \
115             "return (function(evt){";
116     code.append(m_code);
117     // Insert '\n' otherwise //-style comments could break the handler.
118     code.append(  "\n}).call(this, evt);}}}})");
119     v8::Handle<v8::String> codeExternalString = v8ExternalString(code);
120     v8::Handle<v8::Script> script = V8Proxy::compileScript(codeExternalString, m_sourceURL, m_position);
121     if (!script.IsEmpty()) {
122         v8::Local<v8::Value> value = proxy->runScript(script, false);
123         if (!value.IsEmpty()) {
124             ASSERT(value->IsFunction());
125 
126             v8::Local<v8::Function> wrappedFunction = v8::Local<v8::Function>::Cast(value);
127 
128             // Change the toString function on the wrapper function to avoid it
129             // returning the source for the actual wrapper function. Instead it
130             // returns source for a clean wrapper function with the event
131             // argument wrapping the event source code. The reason for this is
132             // that some web sites use toString on event functions and eval the
133             // source returned (sometimes a RegExp is applied as well) for some
134             // other use. That fails miserably if the actual wrapper source is
135             // returned.
136             DEFINE_STATIC_LOCAL(v8::Persistent<v8::FunctionTemplate>, toStringTemplate, ());
137             if (toStringTemplate.IsEmpty())
138                 toStringTemplate = v8::Persistent<v8::FunctionTemplate>::New(v8::FunctionTemplate::New(V8LazyEventListenerToString));
139             v8::Local<v8::Function> toStringFunction;
140             if (!toStringTemplate.IsEmpty())
141                 toStringFunction = toStringTemplate->GetFunction();
142             if (!toStringFunction.IsEmpty()) {
143                 String toStringResult = "function ";
144                 toStringResult.append(m_functionName);
145                 toStringResult.append("(");
146                 toStringResult.append(m_isSVGEvent ? "evt" : "event");
147                 toStringResult.append(") {\n  ");
148                 toStringResult.append(m_code);
149                 toStringResult.append("\n}");
150                 wrappedFunction->SetHiddenValue(V8HiddenPropertyName::toStringString(), v8ExternalString(toStringResult));
151                 wrappedFunction->Set(v8::String::New("toString"), toStringFunction);
152             }
153 
154             wrappedFunction->SetName(v8::String::New(fromWebCoreString(m_functionName), m_functionName.length()));
155 
156             setListenerObject(wrappedFunction);
157         }
158     }
159 }
160 
161 } // namespace WebCore
162