WebCore/dom/ScriptElement.cpp
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/dom/ScriptElement.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,335 @@
+/*
+ * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
+ *           (C) 1999 Antti Koivisto (koivisto@kde.org)
+ *           (C) 2001 Dirk Mueller (mueller@kde.org)
+ * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@kde.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "config.h"
+#include "ScriptElement.h"
+
+#include "CachedScript.h"
+#include "DocLoader.h"
+#include "Document.h"
+#include "Frame.h"
+#include "FrameLoader.h"
+#include "HTMLNames.h"
+#include "HTMLScriptElement.h"
+#include "MIMETypeRegistry.h"
+#include "Page.h"
+#include "ScriptController.h"
+#include "ScriptSourceCode.h"
+#include "ScriptValue.h"
+#include "Settings.h"
+#include "StringHash.h"
+#include "Text.h"
+#include <wtf/StdLibExtras.h>
+
+#if ENABLE(SVG)
+#include "SVGNames.h"
+#include "SVGScriptElement.h"
+#endif
+
+namespace WebCore {
+
+void ScriptElement::insertedIntoDocument(ScriptElementData& data, const String& sourceUrl)
+{
+    if (data.createdByParser())
+        return;
+
+    if (!sourceUrl.isEmpty()) {
+        data.requestScript(sourceUrl);
+        return;
+    }
+
+    // If there's an empty script node, we shouldn't evaluate the script
+    // because if a script is inserted afterwards (by setting text or innerText)
+    // it should be evaluated, and evaluateScript only evaluates a script once.
+    data.evaluateScript(ScriptSourceCode(data.scriptContent(), data.element()->document()->url())); // FIXME: Provide a real starting line number here.
+}
+
+void ScriptElement::removedFromDocument(ScriptElementData& data)
+{
+    // Eventually stop loading any not-yet-finished content
+    data.stopLoadRequest();
+}
+
+void ScriptElement::childrenChanged(ScriptElementData& data)
+{
+    if (data.createdByParser())
+        return;
+
+    Element* element = data.element();
+
+    // If a node is inserted as a child of the script element
+    // and the script element has been inserted in the document
+    // we evaluate the script.
+    if (element->inDocument() && element->firstChild())
+        data.evaluateScript(ScriptSourceCode(data.scriptContent(), element->document()->url())); // FIXME: Provide a real starting line number here
+}
+
+static inline bool useHTML5Parser(Document* document)
+{
+    ASSERT(document);
+    Settings* settings = document->page() ? document->page()->settings() : 0;
+    return settings && settings->html5ParserEnabled();
+}
+
+void ScriptElement::finishParsingChildren(ScriptElementData& data, const String& sourceUrl)
+{
+    // The parser just reached </script>. If we have no src and no text,
+    // allow dynamic loading later.
+    if (sourceUrl.isEmpty() && data.scriptContent().isEmpty())
+        data.setCreatedByParser(false);
+}
+
+void ScriptElement::handleSourceAttribute(ScriptElementData& data, const String& sourceUrl)
+{
+    if (data.ignoresLoadRequest() || sourceUrl.isEmpty())
+        return;
+
+    data.requestScript(sourceUrl);
+}
+
+// Helper function
+static bool isSupportedJavaScriptLanguage(const String& language)
+{
+    typedef HashSet<String, CaseFoldingHash> LanguageSet;
+    DEFINE_STATIC_LOCAL(LanguageSet, languages, ());
+    if (languages.isEmpty()) {
+        languages.add("javascript");
+        languages.add("javascript");
+        languages.add("javascript1.0");
+        languages.add("javascript1.1");
+        languages.add("javascript1.2");
+        languages.add("javascript1.3");
+        languages.add("javascript1.4");
+        languages.add("javascript1.5");
+        languages.add("javascript1.6");
+        languages.add("javascript1.7");
+        languages.add("livescript");
+        languages.add("ecmascript");
+        languages.add("jscript");                
+    }
+
+    return languages.contains(language);
+}
+
+// ScriptElementData
+ScriptElementData::ScriptElementData(ScriptElement* scriptElement, Element* element)
+    : m_scriptElement(scriptElement)
+    , m_element(element)
+    , m_cachedScript(0)
+    , m_createdByParser(false)
+    , m_requested(false)
+    , m_evaluated(false)
+    , m_firedLoad(false)
+{
+    ASSERT(m_scriptElement);
+    ASSERT(m_element);
+}
+
+ScriptElementData::~ScriptElementData()
+{
+    stopLoadRequest();
+}
+
+void ScriptElementData::requestScript(const String& sourceUrl)
+{
+    Document* document = m_element->document();
+
+    // FIXME: Eventually we'd like to evaluate scripts which are inserted into a 
+    // viewless document but this'll do for now.
+    // See http://bugs.webkit.org/show_bug.cgi?id=5727
+    if (!document->frame())
+        return;
+
+    if (!m_element->dispatchBeforeLoadEvent(sourceUrl))
+        return;
+
+    ASSERT(!m_cachedScript);
+    m_cachedScript = document->docLoader()->requestScript(sourceUrl, scriptCharset());
+    m_requested = true;
+
+    // m_createdByParser is never reset - always resied at the initial value set while parsing.
+    // m_evaluated is left untouched as well to avoid script reexecution, if a <script> element
+    // is removed and reappended to the document.
+    m_firedLoad = false;
+
+    if (m_cachedScript) {
+        m_cachedScript->addClient(this);
+        return;
+    }
+
+    m_scriptElement->dispatchErrorEvent();
+}
+
+void ScriptElementData::evaluateScript(const ScriptSourceCode& sourceCode)
+{
+    if (m_evaluated || sourceCode.isEmpty() || !shouldExecuteAsJavaScript())
+        return;
+
+    if (Frame* frame = m_element->document()->frame()) {
+        if (!frame->script()->canExecuteScripts(AboutToExecuteScript))
+            return;
+
+        m_evaluated = true;
+
+        frame->script()->evaluate(sourceCode);
+        Document::updateStyleForAllDocuments();
+    }
+}
+
+void ScriptElementData::stopLoadRequest()
+{
+    if (m_cachedScript) {
+        m_cachedScript->removeClient(this);
+        m_cachedScript = 0;
+    }
+}
+
+void ScriptElementData::execute(CachedScript* cachedScript)
+{
+    ASSERT(cachedScript);
+    if (cachedScript->errorOccurred())
+        m_scriptElement->dispatchErrorEvent();
+    else {
+        evaluateScript(ScriptSourceCode(cachedScript));
+        m_scriptElement->dispatchLoadEvent();
+    }
+    cachedScript->removeClient(this);
+}
+
+void ScriptElementData::notifyFinished(CachedResource* o)
+{
+    ASSERT_UNUSED(o, o == m_cachedScript);
+    m_element->document()->executeScriptSoon(this, m_cachedScript);
+    m_cachedScript = 0;
+}
+
+bool ScriptElementData::ignoresLoadRequest() const
+{
+    return m_evaluated || m_requested || m_createdByParser || !m_element->inDocument();
+}
+
+bool ScriptElementData::shouldExecuteAsJavaScript() const
+{
+    /*
+         Mozilla 1.8 accepts javascript1.0 - javascript1.7, but WinIE 7 accepts only javascript1.1 - javascript1.3.
+         Mozilla 1.8 and WinIE 7 both accept javascript and livescript.
+         WinIE 7 accepts ecmascript and jscript, but Mozilla 1.8 doesn't.
+         Neither Mozilla 1.8 nor WinIE 7 accept leading or trailing whitespace.
+         We want to accept all the values that either of these browsers accept, but not other values.
+     */
+    String type = m_scriptElement->typeAttributeValue();
+    if (!type.isEmpty()) {
+        if (!MIMETypeRegistry::isSupportedJavaScriptMIMEType(type.stripWhiteSpace().lower()))
+            return false;
+    } else {
+        String language = m_scriptElement->languageAttributeValue();
+        if (!language.isEmpty() && !isSupportedJavaScriptLanguage(language))
+            return false;
+    }    
+
+    // No type or language is specified, so we assume the script to be JavaScript.
+    // We don't yet support setting event listeners via the 'for' attribute for scripts.
+    // If there is such an attribute it's likely better to not execute the script than to do so
+    // immediately and unconditionally.
+    // FIXME: After <rdar://problem/4471751> / https://bugs.webkit.org/show_bug.cgi?id=16915 are resolved 
+    // and we support the for syntax in script tags, this check can be removed and we should just
+    // return 'true' here.
+    String forAttribute = m_scriptElement->forAttributeValue();
+    String eventAttribute = m_scriptElement->eventAttributeValue();
+    if (forAttribute.isEmpty() || eventAttribute.isEmpty())
+        return true;
+    
+    forAttribute = forAttribute.stripWhiteSpace();
+    eventAttribute = eventAttribute.stripWhiteSpace();
+    return equalIgnoringCase(forAttribute, "window") && (equalIgnoringCase(eventAttribute, "onload") || equalIgnoringCase(eventAttribute, "onload()"));
+}
+
+String ScriptElementData::scriptCharset() const
+{
+    // First we try to get encoding from charset attribute.
+    String charset = m_scriptElement->charsetAttributeValue().stripWhiteSpace();
+
+    // If charset has not been declared in script tag, fall back to frame encoding.
+    if (charset.isEmpty()) {
+        if (Frame* frame = m_element->document()->frame())
+            charset = frame->loader()->writer()->encoding();
+    }
+
+    return charset;
+}
+
+String ScriptElementData::scriptContent() const
+{
+    Vector<UChar> val;
+    Text* firstTextNode = 0;
+    bool foundMultipleTextNodes = false;
+
+    for (Node* n = m_element->firstChild(); n; n = n->nextSibling()) {
+        if (!n->isTextNode())
+            continue;
+
+        Text* t = static_cast<Text*>(n);
+        if (foundMultipleTextNodes)
+            append(val, t->data());
+        else if (firstTextNode) {
+            append(val, firstTextNode->data());
+            append(val, t->data());
+            foundMultipleTextNodes = true;
+        } else
+            firstTextNode = t;
+    }
+
+    if (firstTextNode && !foundMultipleTextNodes)
+        return firstTextNode->data();
+
+    return String::adopt(val);
+}
+
+bool ScriptElementData::isAsynchronous() const
+{
+    // Only external scripts may be asynchronous.
+    // See: http://dev.w3.org/html5/spec/Overview.html#attr-script-async
+    return !m_scriptElement->sourceAttributeValue().isEmpty() && m_scriptElement->asyncAttributeValue();
+}
+
+bool ScriptElementData::isDeferred() const
+{
+    // Only external scripts may be deferred and async trumps defer to allow for backward compatibility.
+    // See: http://dev.w3.org/html5/spec/Overview.html#attr-script-defer
+    return !m_scriptElement->sourceAttributeValue().isEmpty() && !m_scriptElement->asyncAttributeValue() && m_scriptElement->deferAttributeValue();
+}
+
+ScriptElement* toScriptElement(Element* element)
+{
+    if (element->isHTMLElement() && element->hasTagName(HTMLNames::scriptTag))
+        return static_cast<HTMLScriptElement*>(element);
+
+#if ENABLE(SVG)
+    if (element->isSVGElement() && element->hasTagName(SVGNames::scriptTag))
+        return static_cast<SVGScriptElement*>(element);
+#endif
+
+    return 0;
+}
+
+}