| /* |
| * 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/add_head_filter.h" |
| |
| #include "base/logging.h" |
| #include "pagespeed/kernel/html/html_element.h" |
| #include "pagespeed/kernel/html/html_name.h" |
| #include "pagespeed/kernel/html/html_parse.h" |
| |
| namespace net_instaweb { |
| |
| AddHeadFilter::AddHeadFilter(HtmlParse* html_parse, bool combine_multiple_heads) |
| : html_parse_(html_parse), |
| combine_multiple_heads_(combine_multiple_heads), |
| found_head_(false), |
| head_element_(NULL) { |
| } |
| |
| AddHeadFilter::~AddHeadFilter() {} |
| |
| void AddHeadFilter::StartDocument() { |
| found_head_ = false; |
| head_element_ = NULL; |
| } |
| |
| void AddHeadFilter::StartElement(HtmlElement* element) { |
| if (!found_head_) { |
| if (element->keyword() == HtmlName::kHead) { |
| found_head_ = true; |
| head_element_ = element; |
| } else if (element->keyword() != HtmlName::kHtml) { |
| // Add head before first non-head non-html element (if no head found yet). |
| head_element_ = html_parse_->NewElement( |
| element->parent(), HtmlName::kHead); |
| html_parse_->InsertNodeBeforeNode(element, head_element_); |
| found_head_ = true; |
| } |
| } |
| } |
| |
| void AddHeadFilter::EndElement(HtmlElement* element) { |
| if (combine_multiple_heads_ && |
| (element->keyword() == HtmlName::kHead) && (element != head_element_) && |
| (head_element_ != NULL) && html_parse_->IsRewritable(head_element_)) { |
| // Combine heads |
| if (!(html_parse_->MoveCurrentInto(head_element_) && |
| html_parse_->DeleteSavingChildren(element))) { |
| LOG(DFATAL) << "Failed to move or delete head in " << html_parse_->url(); |
| } |
| } |
| } |
| |
| void AddHeadFilter::Flush() { |
| // Cannot combine heads across flush, so we NULL the pointer. |
| head_element_ = NULL; |
| } |
| |
| void AddHeadFilter::EndDocument() { |
| if (!found_head_) { |
| // Degenerate case: page contains no elements (or only <html> elements). |
| head_element_ = html_parse_->NewElement(NULL, HtmlName::kHead); |
| html_parse_->InsertNodeBeforeCurrent(head_element_); |
| found_head_ = true; |
| } |
| } |
| |
| } // namespace net_instaweb |
