tools/aapt2/link/XmlNamespaceRemover.cpp

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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.
 */

#include "link/Linkers.h"

#include <algorithm>

#include "ResourceTable.h"

namespace aapt {

namespace {

/**
 * Visits each xml Node, removing URI references and nested namespaces.
 */
class XmlVisitor : public xml::Visitor {
 public:
  explicit XmlVisitor(bool keep_uris) : keep_uris_(keep_uris) {}

  void Visit(xml::Element* el) override {
    // Strip namespaces
    for (auto& child : el->children) {
      while (child && xml::NodeCast<xml::Namespace>(child.get())) {
        if (child->children.empty()) {
          child = {};
        } else {
          child = std::move(child->children.front());
          child->parent = el;
        }
      }
    }
    el->children.erase(
        std::remove_if(el->children.begin(), el->children.end(),
                       [](const std::unique_ptr<xml::Node>& child) -> bool {
                         return child == nullptr;
                       }),
        el->children.end());

    if (!keep_uris_) {
      for (xml::Attribute& attr : el->attributes) {
        attr.namespace_uri = std::string();
      }
      el->namespace_uri = std::string();
    }
    xml::Visitor::Visit(el);
  }

 private:
  DISALLOW_COPY_AND_ASSIGN(XmlVisitor);

  bool keep_uris_;
};

}  // namespace

bool XmlNamespaceRemover::Consume(IAaptContext* context,
                                  xml::XmlResource* resource) {
  if (!resource->root) {
    return false;
  }
  // Replace any root namespaces until the root is a non-namespace node
  while (xml::NodeCast<xml::Namespace>(resource->root.get())) {
    if (resource->root->children.empty()) {
      break;
    }
    resource->root = std::move(resource->root->children.front());
    resource->root->parent = nullptr;
  }
  XmlVisitor visitor(keep_uris_);
  resource->root->Accept(&visitor);
  return true;
}

}  // namespace aapt