chrome/utility/media_galleries/iapps_xml_utils.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_UTILITY_MEDIA_GALLERIES_IAPPS_XML_UTILS_H_
   6 #define CHROME_UTILITY_MEDIA_GALLERIES_IAPPS_XML_UTILS_H_
   7
   8 #include <set>
   9 #include <string>
  10
  11 #include "base/files/file.h"
  12 #include "base/stl_util.h"
  13
  14 class XmlReader;
  15
  16 namespace iapps {
  17
  18 // Like XmlReader::SkipToElement, but will advance to the next open tag if the
  19 // cursor is on a close tag.
  20 bool SkipToNextElement(XmlReader* reader);
  21
  22 // Traverse |reader| looking for a node named |name| at the current depth
  23 // of |reader|.
  24 bool SeekToNodeAtCurrentDepth(XmlReader* reader, const std::string& name);
  25
  26 // Search within a "dict" node for |key|. The cursor must be on the starting
  27 // "dict" node when entering this function.
  28 bool SeekInDict(XmlReader* reader, const std::string& key);
  29
  30 // Get the value out of a string node.
  31 bool ReadString(XmlReader* reader, std::string* result);
  32
  33 // Get the value out of an integer node.
  34 bool ReadInteger(XmlReader* reader, uint64* result);
  35
  36 // Read in the contents of the given library xml |file| and return as a string.
  37 std::string ReadFileAsString(base::File file);
  38
  39 // Contains the common code and main loop for reading the key/values
  40 // of an XML dict. The derived class must implement |HandleKeyImpl()|
  41 // which is called with each key, and may re-implement |ShouldLoop()|,
  42 // |FinishedOk()| and/or |AllowRepeats()|.
  43 class XmlDictReader {
  44  public:
  45   explicit XmlDictReader(XmlReader* reader);
  46   virtual ~XmlDictReader();
  47
  48   // The main loop of this class. Reads all the keys in the
  49   // current element and calls |HandleKey()| with each.
  50   bool Read();
  51
  52   // Re-implemented by derived class if it should bail from the
  53   // loop earlier, such as if it encountered all required fields.
  54   virtual bool ShouldLoop();
  55
  56   // Called by |Read()| with each key. Calls derived |HandleKeyImpl()|.
  57   bool HandleKey(const std::string& key);
  58
  59   virtual bool HandleKeyImpl(const std::string& key) = 0;
  60
  61   // Re-implemented by the derived class (to return true) if
  62   // it should allow fields to be repeated, but skipped.
  63   virtual bool AllowRepeats();
  64
  65   // Re-implemented by derived class if it should test for required
  66   // fields instead of just returning true.
  67   virtual bool FinishedOk();
  68
  69   // A convenience function for the derived classes.
  70   // Skips to next element.
  71   bool SkipToNext();
  72
  73   // A convenience function for the derived classes.
  74   // Used to test if all required keys have been encountered.
  75   bool Found(const std::string& key) const;
  76
  77  protected:
  78   XmlReader* reader_;
  79
  80  private:
  81   // The keys that the reader has run into in this element.
  82   std::set<std::string> found_;
  83
  84   DISALLOW_COPY_AND_ASSIGN(XmlDictReader);
  85 };
  86
  87 }  // namespace iapps
  88
  89 #endif  // CHROME_UTILITY_MEDIA_GALLERIES_IAPPS_XML_UTILS_H_