| /* |
| * 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/rewrite_filter.h" |
| |
| #include "net/instaweb/rewriter/public/resource.h" |
| #include "net/instaweb/rewriter/public/rewrite_driver.h" |
| #include "pagespeed/kernel/base/charset_util.h" |
| #include "pagespeed/kernel/base/string_util.h" |
| #include "util/utf8/public/unicodetext.h" |
| #include "webutil/css/parser.h" |
| |
| namespace net_instaweb { |
| |
| class RewriteContext; |
| |
| RewriteFilter::~RewriteFilter() { |
| } |
| |
| void RewriteFilter::DetermineEnabled(GoogleString* disabled_reason) { |
| set_is_enabled(true); |
| if (UsesPropertyCacheDomCohort()) { |
| driver()->set_write_property_cache_dom_cohort(true); |
| } |
| } |
| |
| const UrlSegmentEncoder* RewriteFilter::encoder() const { |
| return driver()->default_encoder(); |
| } |
| |
| bool RewriteFilter::ComputeOnTheFly() const { |
| return false; |
| } |
| |
| RewriteContext* RewriteFilter::MakeRewriteContext() { |
| return NULL; |
| } |
| |
| RewriteContext* RewriteFilter::MakeNestedRewriteContext( |
| RewriteContext* parent, const ResourceSlotPtr& slot) { |
| return NULL; |
| } |
| |
| StringPiece RewriteFilter::GetCharsetForScript( |
| const Resource* script, |
| const StringPiece attribute_charset, |
| const StringPiece enclosing_charset) { |
| // 1. If the script has a Content-Type with a charset, use that. |
| if (!script->charset().empty()) { |
| return script->charset(); |
| } |
| |
| // 2. If the element has a charset attribute, use that. |
| if (!attribute_charset.empty()) { |
| return attribute_charset; |
| } |
| |
| // 3. If the script has a BOM, use that. |
| StringPiece bom_charset = |
| GetCharsetForBom(script->ExtractUncompressedContents()); |
| if (!bom_charset.empty()) { |
| return bom_charset; |
| } |
| |
| // 4. Use the charset of the enclosing page, if any. |
| if (!enclosing_charset.empty()) { |
| return enclosing_charset; |
| } |
| |
| // Well, we really have no idea. |
| return StringPiece(NULL); |
| } |
| |
| GoogleString RewriteFilter::GetCharsetForStylesheet( |
| const Resource* stylesheet, |
| const StringPiece attribute_charset, |
| const StringPiece enclosing_charset) { |
| // 1. If the stylesheet has a Content-Type with a charset, use that, else |
| if (!stylesheet->charset().empty()) { |
| return stylesheet->charset().as_string(); |
| } |
| |
| // 2. If the stylesheet has an initial @charset, use that. |
| StringPiece css(stylesheet->ExtractUncompressedContents()); |
| StripUtf8Bom(&css); |
| Css::Parser parser(css); |
| UnicodeText css_charset = parser.ExtractCharset(); |
| if (parser.errors_seen_mask() == 0) { |
| GoogleString at_charset = UnicodeTextToUTF8(css_charset); |
| if (!at_charset.empty()) { |
| return at_charset; |
| } |
| } |
| |
| // 3. If the stylesheet has a BOM, use that. |
| StringPiece bom_charset = |
| GetCharsetForBom(stylesheet->ExtractUncompressedContents()); |
| if (!bom_charset.empty()) { |
| return bom_charset.as_string(); |
| } |
| |
| // 4. If the element has a charset attribute, use that. |
| if (!attribute_charset.empty()) { |
| return attribute_charset.as_string(); |
| } |
| |
| // 5. Use the charset of the enclosing page, if any. |
| if (!enclosing_charset.empty()) { |
| return enclosing_charset.as_string(); |
| } |
| |
| // Well, we really have no idea. |
| return GoogleString(); |
| } |
| |
| const RewriteOptions::Filter* RewriteFilter::RelatedFilters( |
| int* num_filters) const { |
| *num_filters = 0; |
| return NULL; |
| } |
| |
| } // namespace net_instaweb |