| /* |
| * 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. |
| */ |
| |
| // Authors: jmarantz@google.com (Joshua Marantz) |
| // jefftk@google.com (Jeff Kaufman) |
| |
| #include "net/instaweb/rewriter/public/resource_tag_scanner.h" |
| |
| #include "net/instaweb/rewriter/public/css_tag_scanner.h" |
| #include "net/instaweb/rewriter/public/rewrite_options.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/http/semantic_type.h" |
| |
| namespace net_instaweb { |
| namespace resource_tag_scanner { |
| |
| const char kIcon[] = "icon"; // favicons |
| |
| // See http://developer.apple.com/library/ios/#DOCUMENTATION/ |
| // AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ |
| // ConfiguringWebApplications.html |
| const char kAppleTouchIcon[] = "apple-touch-icon"; |
| const char kAppleTouchIconPrecomposed[] = "apple-touch-icon-precomposed"; |
| const char kAppleTouchStartupImage[] = "apple-touch-startup-image"; |
| |
| // Below are the values of the "rel" attribute of LINK tag which are relevant to |
| // DNS prefetch. |
| const char kRelPrefetch[] = "prefetch"; |
| const char kRelDnsPrefetch[] = "dns-prefetch"; |
| |
| const char kAttrValImage[] = "image"; // <input type="image" src=...> |
| |
| namespace { |
| |
| bool IsAttributeValid(HtmlElement::Attribute* attr) { |
| return attr != NULL && !attr->decoding_error(); |
| } |
| |
| semantic_type::Category CategorizeAttributeBySpec( |
| const HtmlElement* element, HtmlName::Keyword attribute_name) { |
| switch (element->keyword()) { |
| case HtmlName::kLink: { |
| // See http://www.whatwg.org/specs/web-apps/current-work/multipage/links.html#linkTypes |
| if (attribute_name != HtmlName::kHref) { |
| return semantic_type::kUndefined; |
| } |
| const HtmlElement::Attribute* rel_attr = |
| element->FindAttribute(HtmlName::kRel); |
| if (rel_attr == NULL) { |
| return semantic_type::kHyperlink; |
| } |
| if (CssTagScanner::IsStylesheetOrAlternate( |
| rel_attr->DecodedValueOrNull())) { |
| return semantic_type::kStylesheet; |
| } |
| // Ignore keywords we don't recognize, to deal with cases like |
| // "shortcut icon" where shortcut is simply ignored. |
| StringPieceVector values; |
| SplitStringPieceToVector(rel_attr->DecodedValueOrNull(), |
| " ", &values, true /* skip empty */); |
| // Image takes precedence over prefetch, so look for images first. |
| for (int i = 0, n = values.size(); i < n; ++i) { |
| if (StringCaseEqual(values[i], kIcon) || |
| StringCaseEqual(values[i], kAppleTouchIcon) || |
| StringCaseEqual(values[i], kAppleTouchIconPrecomposed) || |
| StringCaseEqual(values[i], kAppleTouchStartupImage)) { |
| return semantic_type::kImage; |
| } |
| } |
| for (int i = 0, n = values.size(); i < n; ++i) { |
| if (StringCaseEqual(values[i], kRelPrefetch) || |
| StringCaseEqual(values[i], kRelDnsPrefetch)) { |
| return semantic_type::kPrefetch; |
| } |
| } |
| return semantic_type::kUndefined; |
| } |
| case HtmlName::kScript: |
| return (attribute_name == HtmlName::kSrc ? |
| semantic_type::kScript : semantic_type::kUndefined); |
| case HtmlName::kImg: |
| if (attribute_name == HtmlName::kSrc) { |
| return semantic_type::kImage; |
| } |
| if (attribute_name == HtmlName::kLongdesc) { |
| return semantic_type::kHyperlink; |
| } |
| return semantic_type::kUndefined; |
| case HtmlName::kBody: |
| if (attribute_name == HtmlName::kBackground) { |
| return semantic_type::kImage; |
| } |
| if (attribute_name == HtmlName::kCite) { |
| return semantic_type::kHyperlink; |
| } |
| return semantic_type::kUndefined; |
| case HtmlName::kTd: |
| case HtmlName::kTh: |
| case HtmlName::kTable: |
| case HtmlName::kTbody: |
| case HtmlName::kTfoot: |
| case HtmlName::kThead: |
| return (attribute_name == HtmlName::kBackground ? |
| semantic_type::kImage : semantic_type::kUndefined); |
| case HtmlName::kInput: |
| if (attribute_name == HtmlName::kFormaction) { |
| return semantic_type::kHyperlink; |
| } |
| if (StringCaseEqual(element->AttributeValue(HtmlName::kType), |
| kAttrValImage) && |
| attribute_name == HtmlName::kSrc) { |
| return semantic_type::kImage; |
| } |
| return semantic_type::kUndefined; |
| case HtmlName::kCommand: |
| return (attribute_name == HtmlName::kIcon ? |
| semantic_type::kImage : semantic_type::kUndefined); |
| case HtmlName::kA: |
| case HtmlName::kArea: |
| return (attribute_name == HtmlName::kHref ? |
| semantic_type::kHyperlink : semantic_type::kUndefined); |
| case HtmlName::kForm: |
| return (attribute_name == HtmlName::kAction ? |
| semantic_type::kHyperlink : semantic_type::kUndefined); |
| case HtmlName::kVideo: |
| if (attribute_name == HtmlName::kSrc) { |
| return semantic_type::kOtherResource; |
| } |
| if (attribute_name == HtmlName::kPoster) { |
| return semantic_type::kImage; |
| } |
| return semantic_type::kUndefined; |
| case HtmlName::kAudio: |
| case HtmlName::kSource: |
| case HtmlName::kTrack: |
| case HtmlName::kEmbed: |
| return (attribute_name == HtmlName::kSrc ? |
| semantic_type::kOtherResource : semantic_type::kUndefined); |
| case HtmlName::kFrame: |
| case HtmlName::kIframe: |
| if (attribute_name == HtmlName::kSrc) { |
| return semantic_type::kOtherResource; |
| } |
| if (attribute_name == HtmlName::kLongdesc) { |
| return semantic_type::kHyperlink; |
| } |
| return semantic_type::kUndefined; |
| case HtmlName::kHtml: |
| return (attribute_name == HtmlName::kManifest ? |
| semantic_type::kOtherResource : semantic_type::kUndefined); |
| case HtmlName::kBlockquote: |
| case HtmlName::kQ: |
| case HtmlName::kIns: |
| case HtmlName::kDel: |
| return (attribute_name == HtmlName::kCite ? |
| semantic_type::kHyperlink : semantic_type::kUndefined); |
| case HtmlName::kButton: |
| return (attribute_name == HtmlName::kFormaction ? |
| semantic_type::kHyperlink : semantic_type::kUndefined); |
| default: |
| break; |
| } |
| return semantic_type::kUndefined; |
| } |
| |
| } // namespace |
| |
| semantic_type::Category CategorizeAttribute( |
| const HtmlElement* element, |
| const HtmlElement::Attribute* attribute, |
| const RewriteOptions* options) { |
| |
| if (attribute == NULL) { |
| return semantic_type::kUndefined; |
| } |
| |
| // Handle user-defined attributes. Do this first so spec-defined attributes |
| // can be overriden. |
| for (int i = 0, n = options->num_url_valued_attributes(); i < n; ++i) { |
| StringPiece element_i; |
| StringPiece attribute_i; |
| semantic_type::Category category_i; |
| options->UrlValuedAttribute(i, &element_i, &attribute_i, &category_i); |
| if (StringCaseEqual(element->name_str(), element_i) && |
| StringCaseEqual(attribute->name_str(), attribute_i)) { |
| return category_i; |
| } |
| if (element->keyword() == HtmlName::kStyle) { |
| // When inlining we turn <link> into <style> while preserving attributes. |
| // This means that any custom attributes defined for <link> should also be |
| // interpreted on <style>. |
| if (StringCaseEqual("link", element_i) && |
| StringCaseEqual(attribute->name_str(), attribute_i)) { |
| return category_i; |
| } |
| } |
| } |
| |
| // Handle spec-defined attributes. |
| semantic_type::Category spec_category = |
| CategorizeAttributeBySpec(element, attribute->keyword()); |
| if (spec_category != semantic_type::kUndefined) { |
| return spec_category; |
| } |
| |
| return semantic_type::kUndefined; |
| } |
| |
| void ScanElement(HtmlElement* element, |
| const RewriteOptions* options, |
| UrlCategoryVector* attributes) { |
| HtmlElement::AttributeList* attrs = element->mutable_attributes(); |
| for (HtmlElement::AttributeIterator i = attrs->begin(); |
| i != attrs->end(); ++i) { |
| UrlCategoryPair url_category_pair; |
| url_category_pair.url = i.Get(); |
| if (IsAttributeValid(url_category_pair.url)) { |
| url_category_pair.category = CategorizeAttribute( |
| element, url_category_pair.url, options); |
| if (url_category_pair.category != semantic_type::kUndefined) { |
| attributes->push_back(url_category_pair); |
| } |
| } |
| } |
| } |
| |
| } // namespace resource_tag_scanner |
| } // namespace net_instaweb |
