| /* |
| * Copyright 2011 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) |
| |
| #ifndef NET_INSTAWEB_REWRITER_PUBLIC_SIMPLE_TEXT_FILTER_H_ |
| #define NET_INSTAWEB_REWRITER_PUBLIC_SIMPLE_TEXT_FILTER_H_ |
| |
| #include "net/instaweb/rewriter/public/output_resource_kind.h" |
| #include "net/instaweb/rewriter/public/resource.h" // for ResourcePtr |
| #include "net/instaweb/rewriter/public/resource_slot.h" |
| #include "net/instaweb/rewriter/public/rewrite_filter.h" |
| #include "net/instaweb/rewriter/public/server_context.h" |
| #include "net/instaweb/rewriter/public/single_rewrite_context.h" |
| #include "pagespeed/kernel/base/basictypes.h" |
| #include "pagespeed/kernel/base/string.h" |
| #include "pagespeed/kernel/base/string_util.h" |
| #include "pagespeed/kernel/html/html_element.h" |
| |
| namespace net_instaweb { |
| |
| class RewriteContext; |
| class RewriteDriver; |
| |
| // Generic hyper-simple rewriter class, which retains zero state |
| // across different rewrites; just transforming text to other text, |
| // returning whether anything changed. This text may come from |
| // resource files or inline in HTML, though the latter is NYI. |
| // |
| // Implementors of this mechanism do not have to worry about |
| // resource-loading, cache reading/writing, expiration times, etc. |
| // Subclass SimpleTextFilter::Rewriter to define how to rewrite text. |
| class SimpleTextFilter : public RewriteFilter { |
| public: |
| class Rewriter : public RefCounted<Rewriter> { |
| public: |
| Rewriter() {} |
| virtual bool RewriteText(const StringPiece& url, |
| const StringPiece& in, |
| GoogleString* out, |
| ServerContext* server_context) = 0; |
| virtual HtmlElement::Attribute* FindResourceAttribute( |
| HtmlElement* element) = 0; |
| |
| virtual OutputResourceKind kind() const = 0; |
| virtual const char* id() const = 0; |
| virtual const char* name() const = 0; |
| |
| // See RewriteContext::OptimizationOnly() |
| virtual bool OptimizationOnly() const { return true; } |
| |
| protected: |
| REFCOUNT_FRIEND_DECLARATION(Rewriter); |
| virtual ~Rewriter(); |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(Rewriter); |
| }; |
| |
| typedef RefCountedPtr<Rewriter> RewriterPtr; |
| |
| class Context : public SingleRewriteContext { |
| public: |
| Context(const RewriterPtr& rewriter, RewriteDriver* driver, |
| RewriteContext* parent); |
| virtual ~Context(); |
| virtual void RewriteSingle( |
| const ResourcePtr& input, const OutputResourcePtr& output); |
| |
| protected: |
| virtual const char* id() const { return rewriter_->id(); } |
| virtual OutputResourceKind kind() const { return rewriter_->kind(); } |
| virtual bool OptimizationOnly() const { |
| return rewriter_->OptimizationOnly(); |
| } |
| |
| private: |
| RewriterPtr rewriter_; |
| |
| DISALLOW_COPY_AND_ASSIGN(Context); |
| }; |
| |
| SimpleTextFilter(Rewriter* rewriter, RewriteDriver* driver); |
| virtual ~SimpleTextFilter(); |
| |
| virtual void StartDocumentImpl() {} |
| virtual void EndElementImpl(HtmlElement* element) {} |
| virtual void StartElementImpl(HtmlElement* element); |
| |
| virtual RewriteContext* MakeRewriteContext(); |
| virtual RewriteContext* MakeNestedRewriteContext( |
| RewriteContext* parent, const ResourceSlotPtr& slot); |
| |
| protected: |
| virtual const char* id() const { return rewriter_->id(); } |
| virtual const char* Name() const { return rewriter_->name(); } |
| virtual bool ComputeOnTheFly() const { |
| return rewriter_->kind() == kOnTheFlyResource; |
| } |
| |
| private: |
| RewriterPtr rewriter_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SimpleTextFilter); |
| }; |
| |
| } // namespace net_instaweb |
| |
| #endif // NET_INSTAWEB_REWRITER_PUBLIC_SIMPLE_TEXT_FILTER_H_ |