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      1 /*
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      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
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      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
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     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
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     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
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     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 
     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 
     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 
     74 static v8::Handle<v8::Value> V8LazyEventListenerToString(const v8::Arguments& args)
     75 {
     76     return args.Holder()->GetHiddenValue(V8HiddenPropertyName::toStringString());
     77 }
     78 
     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