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      1 /*
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     10  *     * Redistributions in binary form must reproduce the above
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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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     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "config.h"
     32 #include "bindings/v8/V8LazyEventListener.h"
     33 
     34 #include "V8Document.h"
     35 #include "V8HTMLFormElement.h"
     36 #include "V8Node.h"
     37 #include "bindings/v8/ScriptController.h"
     38 #include "bindings/v8/ScriptSourceCode.h"
     39 #include "bindings/v8/V8Binding.h"
     40 #include "bindings/v8/V8DOMWrapper.h"
     41 #include "bindings/v8/V8HiddenPropertyName.h"
     42 #include "bindings/v8/V8ScriptRunner.h"
     43 #include "core/dom/Document.h"
     44 #include "core/dom/Node.h"
     45 #include "core/html/HTMLElement.h"
     46 #include "core/html/HTMLFormElement.h"
     47 #include "core/inspector/InspectorInstrumentation.h"
     48 #include "core/frame/ContentSecurityPolicy.h"
     49 #include "core/frame/Frame.h"
     50 
     51 #include "wtf/StdLibExtras.h"
     52 
     53 namespace WebCore {
     54 
     55 V8LazyEventListener::V8LazyEventListener(const AtomicString& functionName, const AtomicString& eventParameterName, const String& code, const String sourceURL, const TextPosition& position, Node* node, v8::Isolate* isolate)
     56     : V8AbstractEventListener(true, mainThreadNormalWorld(), isolate)
     57     , m_functionName(functionName)
     58     , m_eventParameterName(eventParameterName)
     59     , m_code(code)
     60     , m_sourceURL(sourceURL)
     61     , m_node(node)
     62     , m_position(position)
     63 {
     64 }
     65 
     66 template<typename T>
     67 v8::Handle<v8::Object> toObjectWrapper(T* domObject, v8::Isolate* isolate)
     68 {
     69     if (!domObject)
     70         return v8::Object::New();
     71     v8::Handle<v8::Value> value = toV8(domObject, v8::Handle<v8::Object>(), isolate);
     72     if (value.IsEmpty())
     73         return v8::Object::New();
     74     return v8::Local<v8::Object>::New(isolate, value.As<v8::Object>());
     75 }
     76 
     77 v8::Local<v8::Value> V8LazyEventListener::callListenerFunction(ExecutionContext* context, v8::Handle<v8::Value> jsEvent, Event* event)
     78 {
     79     v8::Local<v8::Object> listenerObject = getListenerObject(context);
     80     if (listenerObject.IsEmpty())
     81         return v8::Local<v8::Value>();
     82 
     83     v8::Local<v8::Function> handlerFunction = listenerObject.As<v8::Function>();
     84     v8::Local<v8::Object> receiver = getReceiverObject(context, event);
     85     if (handlerFunction.IsEmpty() || receiver.IsEmpty())
     86         return v8::Local<v8::Value>();
     87 
     88     // FIXME: Can |context| be 0 here?
     89     if (!context)
     90         return v8::Local<v8::Value>();
     91 
     92     if (!context->isDocument())
     93         return v8::Local<v8::Value>();
     94 
     95     Frame* frame = toDocument(context)->frame();
     96     if (!frame)
     97         return v8::Local<v8::Value>();
     98 
     99     if (!frame->script().canExecuteScripts(AboutToExecuteScript))
    100         return v8::Local<v8::Value>();
    101 
    102     v8::Handle<v8::Value> parameters[1] = { jsEvent };
    103     return frame->script().callFunction(handlerFunction, receiver, WTF_ARRAY_LENGTH(parameters), parameters);
    104 }
    105 
    106 static void V8LazyEventListenerToString(const v8::FunctionCallbackInfo<v8::Value>& info)
    107 {
    108     v8SetReturnValue(info, info.Holder()->GetHiddenValue(V8HiddenPropertyName::toStringString(info.GetIsolate())));
    109 }
    110 
    111 void V8LazyEventListener::prepareListenerObject(ExecutionContext* context)
    112 {
    113     if (context->isDocument() && !toDocument(context)->allowInlineEventHandlers(m_node, this, m_sourceURL, m_position.m_line)) {
    114         clearListenerObject();
    115         return;
    116     }
    117 
    118     if (hasExistingListenerObject())
    119         return;
    120 
    121     ASSERT(context->isDocument());
    122 
    123     v8::Isolate* isolate = toIsolate(context);
    124     v8::HandleScope handleScope(isolate);
    125 
    126     // Use the outer scope to hold context.
    127     v8::Local<v8::Context> v8Context = toV8Context(context, world());
    128     // Bail out if we cannot get the context.
    129     if (v8Context.IsEmpty())
    130         return;
    131 
    132     v8::Context::Scope scope(v8Context);
    133 
    134     String listenerSource =  InspectorInstrumentation::preprocessEventListener(toDocument(context)->frame(), m_code, m_sourceURL, m_functionName);
    135 
    136     // FIXME: Remove the following 'with' hack.
    137     //
    138     // Nodes other than the document object, when executing inline event
    139     // handlers push document, form owner, and the target node on the scope chain.
    140     // We do this by using 'with' statement.
    141     // See chrome/fast/forms/form-action.html
    142     //     chrome/fast/forms/selected-index-value.html
    143     //     base/fast/overflow/onscroll-layer-self-destruct.html
    144     //
    145     // Don't use new lines so that lines in the modified handler
    146     // have the same numbers as in the original code.
    147     // FIXME: V8 does not allow us to programmatically create object environments so
    148     //        we have to do this hack! What if m_code escapes to run arbitrary script?
    149     //
    150     // Call with 4 arguments instead of 3, pass additional null as the last parameter.
    151     // By calling the function with 4 arguments, we create a setter on arguments object
    152     // which would shadow property "3" on the prototype.
    153     String code = "(function() {"
    154         "with (this[2]) {"
    155         "with (this[1]) {"
    156         "with (this[0]) {"
    157             "return function(" + m_eventParameterName + ") {" +
    158                 listenerSource + "\n" // Insert '\n' otherwise //-style comments could break the handler.
    159             "};"
    160         "}}}})";
    161 
    162     v8::Handle<v8::String> codeExternalString = v8String(isolate, code);
    163 
    164     v8::Local<v8::Value> result = V8ScriptRunner::compileAndRunInternalScript(codeExternalString, isolate, m_sourceURL, m_position, 0);
    165     if (result.IsEmpty())
    166         return;
    167 
    168     // Call the outer function to get the inner function.
    169     ASSERT(result->IsFunction());
    170     v8::Local<v8::Function> intermediateFunction = result.As<v8::Function>();
    171 
    172     HTMLFormElement* formElement = 0;
    173     if (m_node && m_node->isHTMLElement())
    174         formElement = toHTMLElement(m_node)->formOwner();
    175 
    176     v8::Handle<v8::Object> nodeWrapper = toObjectWrapper<Node>(m_node, isolate);
    177     v8::Handle<v8::Object> formWrapper = toObjectWrapper<HTMLFormElement>(formElement, isolate);
    178     v8::Handle<v8::Object> documentWrapper = toObjectWrapper<Document>(m_node ? m_node->ownerDocument() : 0, isolate);
    179 
    180     v8::Local<v8::Object> thisObject = v8::Object::New();
    181     if (thisObject.IsEmpty())
    182         return;
    183     if (!thisObject->ForceSet(v8::Integer::New(0, isolate), nodeWrapper))
    184         return;
    185     if (!thisObject->ForceSet(v8::Integer::New(1, isolate), formWrapper))
    186         return;
    187     if (!thisObject->ForceSet(v8::Integer::New(2, isolate), documentWrapper))
    188         return;
    189 
    190     // FIXME: Remove this code when we stop doing the 'with' hack above.
    191     v8::Local<v8::Value> innerValue = V8ScriptRunner::callInternalFunction(intermediateFunction, thisObject, 0, 0, isolate);
    192     if (innerValue.IsEmpty() || !innerValue->IsFunction())
    193         return;
    194 
    195     v8::Local<v8::Function> wrappedFunction = innerValue.As<v8::Function>();
    196 
    197     // Change the toString function on the wrapper function to avoid it
    198     // returning the source for the actual wrapper function. Instead it
    199     // returns source for a clean wrapper function with the event
    200     // argument wrapping the event source code. The reason for this is
    201     // that some web sites use toString on event functions and eval the
    202     // source returned (sometimes a RegExp is applied as well) for some
    203     // other use. That fails miserably if the actual wrapper source is
    204     // returned.
    205     v8::Handle<v8::FunctionTemplate> toStringTemplate =
    206         V8PerIsolateData::current()->lazyEventListenerToStringTemplate();
    207     if (toStringTemplate.IsEmpty())
    208         toStringTemplate = v8::FunctionTemplate::New(isolate, V8LazyEventListenerToString);
    209     v8::Local<v8::Function> toStringFunction;
    210     if (!toStringTemplate.IsEmpty())
    211         toStringFunction = toStringTemplate->GetFunction();
    212     if (!toStringFunction.IsEmpty()) {
    213         String toStringString = "function " + m_functionName + "(" + m_eventParameterName + ") {\n  " + m_code + "\n}";
    214         wrappedFunction->SetHiddenValue(V8HiddenPropertyName::toStringString(isolate), v8String(isolate, toStringString));
    215         wrappedFunction->Set(v8AtomicString(isolate, "toString"), toStringFunction);
    216     }
    217 
    218     wrappedFunction->SetName(v8String(isolate, m_functionName));
    219 
    220     // FIXME: Remove the following comment-outs.
    221     // See https://bugs.webkit.org/show_bug.cgi?id=85152 for more details.
    222     //
    223     // For the time being, we comment out the following code since the
    224     // second parsing can happen.
    225     // // Since we only parse once, there's no need to keep data used for parsing around anymore.
    226     // m_functionName = String();
    227     // m_code = String();
    228     // m_eventParameterName = String();
    229     // m_sourceURL = String();
    230 
    231     setListenerObject(wrappedFunction);
    232 }
    233 
    234 } // namespace WebCore
    235