| /** |
| * 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: jmarantz@google.com (Joshua Marantz) |
| |
| #include "net/instaweb/rewriter/public/css_move_to_head_filter.h" |
| |
| #include "net/instaweb/htmlparse/public/html_parse.h" |
| #include "net/instaweb/htmlparse/public/html_element.h" |
| #include "net/instaweb/util/public/statistics.h" |
| |
| namespace { |
| |
| // names for Statistics variables. |
| const char kCssElements[] = "css_elements"; |
| |
| } // namespace |
| |
| namespace net_instaweb { |
| |
| CssMoveToHeadFilter::CssMoveToHeadFilter(HtmlParse* html_parse, |
| Statistics* statistics) |
| : html_parse_(html_parse), |
| css_tag_scanner_(html_parse), |
| counter_(NULL) { |
| s_head_ = html_parse->Intern("head"); |
| s_noscript_ = html_parse->Intern("noscript"); |
| s_style_ = html_parse->Intern("style"); |
| if (statistics != NULL) { |
| counter_ = statistics->GetVariable(kCssElements); |
| } |
| } |
| |
| void CssMoveToHeadFilter::Initialize(Statistics* statistics) { |
| statistics->AddVariable(kCssElements); |
| } |
| |
| void CssMoveToHeadFilter::StartDocument() { |
| head_element_ = NULL; |
| noscript_element_ = NULL; |
| } |
| |
| void CssMoveToHeadFilter::StartElement(HtmlElement* element) { |
| if (noscript_element_ == NULL && element->tag() == s_noscript_) { |
| noscript_element_ = element; // Record top-level <noscript>. |
| } |
| } |
| |
| void CssMoveToHeadFilter::EndElement(HtmlElement* element) { |
| if ((head_element_ == NULL) && (element->tag() == s_head_)) { |
| head_element_ = element; |
| |
| } else if (element == noscript_element_) { |
| noscript_element_ = NULL; // We are exitting the top level </noscript>. |
| |
| // Do not move anything out of a <noscript> element and we can only move |
| // this to <head> if <head> is still rewritable. |
| } else if (noscript_element_ == NULL && head_element_ != NULL && |
| html_parse_->IsRewritable(head_element_)){ |
| HtmlElement::Attribute* href; |
| const char* media; |
| if (element->tag() == s_style_ || |
| css_tag_scanner_.ParseCssElement(element, &href, &media)) { |
| html_parse_->MoveCurrentInto(head_element_); |
| // TODO(sligocki): It'd be nice to have this pattern simplified. |
| if (counter_ != NULL) { |
| counter_->Add(1); |
| } |
| } |
| } |
| } |
| |
| } // namespace net_instaweb |
