| /* |
| * Copyright 2010 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| // Author: gagansingh@google.com (Gagan Singh) |
| |
| #include "net/instaweb/rewriter/public/js_disable_filter.h" |
| |
| #include "net/instaweb/http/public/log_record.h" |
| #include "net/instaweb/rewriter/public/flush_early_content_writer_filter.h" |
| #include "net/instaweb/rewriter/public/js_defer_disabled_filter.h" |
| #include "net/instaweb/rewriter/public/rewrite_driver.h" |
| #include "net/instaweb/rewriter/public/rewrite_options.h" |
| #include "pagespeed/kernel/base/escaping.h" |
| #include "pagespeed/kernel/base/string.h" |
| #include "pagespeed/kernel/base/string_util.h" |
| #include "pagespeed/kernel/html/html_element.h" |
| #include "pagespeed/kernel/html/html_name.h" |
| #include "pagespeed/kernel/html/html_node.h" |
| #include "pagespeed/kernel/http/user_agent_matcher.h" |
| #include "pagespeed/opt/logging/enums.pb.h" |
| |
| namespace net_instaweb { |
| |
| const char JsDisableFilter::kEnableJsExperimental[] = |
| "window.pagespeed = window.pagespeed || {};" |
| "window.pagespeed.defer_js_experimental=true;"; |
| const char JsDisableFilter::kElementOnloadCode[] = |
| "var elem=this;" |
| "if (this==window) elem=document.body;" |
| "elem.setAttribute('data-pagespeed-loaded', 1)"; |
| |
| JsDisableFilter::JsDisableFilter(RewriteDriver* driver) |
| : CommonFilter(driver), |
| script_tag_scanner_(driver), |
| index_(0), |
| ie_meta_tag_written_(false), |
| max_prefetch_js_elements_(0) { |
| } |
| |
| JsDisableFilter::~JsDisableFilter() { |
| } |
| |
| void JsDisableFilter::DetermineEnabled(GoogleString* disabled_reason) { |
| bool should_apply = JsDeferDisabledFilter::ShouldApply(driver()); |
| set_is_enabled(should_apply); |
| AbstractLogRecord* log_record = driver()->log_record(); |
| if (should_apply) { |
| log_record->LogRewriterHtmlStatus( |
| RewriteOptions::FilterId(RewriteOptions::kDisableJavascript), |
| RewriterHtmlApplication::ACTIVE); |
| } else if (!driver()->flushing_early()) { |
| log_record->LogRewriterHtmlStatus( |
| RewriteOptions::FilterId(RewriteOptions::kDisableJavascript), |
| RewriterHtmlApplication::USER_AGENT_NOT_SUPPORTED); |
| } |
| } |
| |
| void JsDisableFilter::StartDocumentImpl() { |
| index_ = 0; |
| ie_meta_tag_written_ = false; |
| should_look_for_prefetch_js_elements_ = false; |
| prefetch_js_elements_.clear(); |
| prefetch_js_elements_count_ = 0; |
| max_prefetch_js_elements_ = |
| driver()->options()->max_prefetch_js_elements(); |
| prefetch_mechanism_ = |
| driver()->user_agent_matcher()->GetPrefetchMechanism( |
| driver()->user_agent()); |
| } |
| |
| void JsDisableFilter::InsertJsDeferExperimentalScript() { |
| bool defer_js_experimental = |
| driver()->options()->enable_defer_js_experimental(); |
| if (!defer_js_experimental) { |
| return; |
| } |
| // We are not adding this code in js_defer_disabled_filter to avoid |
| // duplication of code for blink and critical line code. |
| HtmlElement* script_node = |
| driver()->NewElement(NULL, HtmlName::kScript); |
| |
| driver()->AddAttribute(script_node, HtmlName::kType, "text/javascript"); |
| driver()->AddAttribute(script_node, HtmlName::kDataPagespeedNoDefer, NULL); |
| HtmlNode* script_code = |
| driver()->NewCharactersNode(script_node, kEnableJsExperimental); |
| InsertNodeAtBodyEnd(script_node); |
| driver()->AppendChild(script_node, script_code); |
| } |
| |
| void JsDisableFilter::InsertMetaTagForIE(HtmlElement* element) { |
| if (ie_meta_tag_written_) { |
| return; |
| } |
| ie_meta_tag_written_ = true; |
| if (!driver()->user_agent_matcher()->IsIe(driver()->user_agent())) { |
| return; |
| } |
| |
| HtmlElement* head_node = element; |
| if (element->keyword() != HtmlName::kHead) { |
| head_node = |
| driver()->NewElement(element->parent(), HtmlName::kHead); |
| driver()->InsertNodeBeforeCurrent(head_node); |
| } |
| // TODO(ksimbili): Don't add the following if there is already a meta tag |
| // and if it's content is greater than IE8 (deferJs supported version). |
| HtmlElement* meta_tag = |
| driver()->NewElement(head_node, HtmlName::kMeta); |
| |
| driver()->AddAttribute(meta_tag, HtmlName::kHttpEquiv, "X-UA-Compatible"); |
| driver()->AddAttribute(meta_tag, HtmlName::kContent, "IE=edge"); |
| driver()->PrependChild(head_node, meta_tag); |
| } |
| |
| void JsDisableFilter::StartElementImpl(HtmlElement* element) { |
| if (element->keyword() == HtmlName::kHead) { |
| if (!ie_meta_tag_written_) { |
| InsertMetaTagForIE(element); |
| } |
| should_look_for_prefetch_js_elements_ = true; |
| } else if (element->keyword() == HtmlName::kBody) { |
| if (!ie_meta_tag_written_) { |
| InsertMetaTagForIE(element); |
| } |
| if (prefetch_js_elements_count_ != 0) { |
| // We have collected some script elements that can be downloaded early. |
| should_look_for_prefetch_js_elements_ = false; |
| // The method to download the scripts differs based on the user agent. |
| // Iframe is used for non-chrome UAs whereas for Chrome, the scripts are |
| // downloaded as Image.src(). |
| if (prefetch_mechanism_ == UserAgentMatcher::kPrefetchImageTag) { |
| HtmlElement* script = driver()->NewElement(element, HtmlName::kScript); |
| driver()->AddAttribute( |
| script, HtmlName::kDataPagespeedNoDefer, NULL); |
| GoogleString script_data = StrCat("(function(){", prefetch_js_elements_, |
| "})()"); |
| driver()->PrependChild(element, script); |
| HtmlNode* script_code = |
| driver()->NewCharactersNode(script, script_data); |
| driver()->AppendChild(script, script_code); |
| } |
| } |
| } else { |
| HtmlElement::Attribute* src; |
| if (script_tag_scanner_.ParseScriptElement(element, &src) == |
| ScriptTagScanner::kJavaScript) { |
| if (element->FindAttribute(HtmlName::kDataPagespeedNoDefer) || |
| element->FindAttribute(HtmlName::kPagespeedNoDefer)) { |
| driver()->log_record()->LogJsDisableFilter( |
| RewriteOptions::FilterId(RewriteOptions::kDisableJavascript), true); |
| return; |
| } |
| |
| // Honor disallow. |
| if (src != NULL && src->DecodedValueOrNull() != NULL) { |
| GoogleUrl abs_url(driver()->base_url(), src->DecodedValueOrNull()); |
| if (abs_url.IsWebValid() && |
| !driver()->options()->IsAllowed(abs_url.Spec())) { |
| driver()->log_record()->LogJsDisableFilter( |
| RewriteOptions::FilterId(RewriteOptions::kDisableJavascript), |
| true); |
| return; |
| } |
| } |
| |
| // TODO(rahulbansal): Add a separate bool to track the inline |
| // scripts till first external script which aren't deferred.1 |
| driver()->log_record()->LogJsDisableFilter( |
| RewriteOptions::FilterId(RewriteOptions::kDisableJavascript), false); |
| |
| // TODO(rahulbansal): Add logging for prioritize scripts |
| if (src != NULL) { |
| if (should_look_for_prefetch_js_elements_ && |
| prefetch_js_elements_count_ < max_prefetch_js_elements_) { |
| GoogleString escaped_source; |
| if (prefetch_mechanism_ == UserAgentMatcher::kPrefetchImageTag) { |
| EscapeToJsStringLiteral(src->DecodedValueOrNull(), false, |
| &escaped_source); |
| StrAppend(&prefetch_js_elements_, StringPrintf( |
| FlushEarlyContentWriterFilter::kPrefetchImageTagHtml, |
| escaped_source.c_str())); |
| } |
| prefetch_js_elements_count_++; |
| } |
| } |
| HtmlElement::Attribute* type = element->FindAttribute(HtmlName::kType); |
| if (type != NULL) { |
| type->set_name(driver()->MakeName(HtmlName::kDataPagespeedOrigType)); |
| } |
| // Delete all type attributes if any. Some sites have more than one type |
| // attribute(duplicate). Chrome and firefox picks up the first type |
| // attribute for the node. |
| while (element->DeleteAttribute(HtmlName::kType)) {} |
| HtmlElement::Attribute* prioritize_attr = element->FindAttribute( |
| HtmlName::kDataPagespeedPrioritize); |
| if (prioritize_attr != NULL && |
| driver()->options()->enable_prioritizing_scripts()) { |
| element->AddAttribute( |
| driver()->MakeName(HtmlName::kType), "text/prioritypsajs", |
| HtmlElement::DOUBLE_QUOTE); |
| } else { |
| element->AddAttribute( |
| driver()->MakeName(HtmlName::kType), "text/psajs", |
| HtmlElement::DOUBLE_QUOTE); |
| } |
| element->AddAttribute(driver()->MakeName(HtmlName::kOrigIndex), |
| IntegerToString(index_++), |
| HtmlElement::DOUBLE_QUOTE); |
| } |
| } |
| |
| HtmlElement::Attribute* onload = element->FindAttribute(HtmlName::kOnload); |
| if (onload != NULL) { |
| // The onload value can be any script. It's not necessary that it is |
| // always javascript. But we don't have any way of identifying it. |
| // For now let us assume it is JS, which is the case in majority. |
| // TODO(ksimbili): Try fixing not adding non-Js code, if we can. |
| // TODO(ksimbili): Call onloads on elements in the same order as they are |
| // triggered. |
| onload->set_name(driver()->MakeName("data-pagespeed-onload")); |
| driver()->AddEscapedAttribute(element, HtmlName::kOnload, |
| kElementOnloadCode); |
| // TODO(sligocki): Should we add onerror handler here too? |
| } |
| } |
| |
| void JsDisableFilter::EndElementImpl(HtmlElement* element) { |
| if (element->keyword() == HtmlName::kHead) { |
| should_look_for_prefetch_js_elements_ = false; |
| } |
| } |
| |
| void JsDisableFilter::EndDocument() { |
| InsertJsDeferExperimentalScript(); |
| } |
| |
| } // namespace net_instaweb |
