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      1 // Copyright (c) 2012 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 CHROMEOS_NETWORK_ONC_ONC_MAPPER_H_
      6 #define CHROMEOS_NETWORK_ONC_ONC_MAPPER_H_
      7 
      8 #include <string>
      9 
     10 #include "base/memory/scoped_ptr.h"
     11 #include "chromeos/chromeos_export.h"
     12 
     13 namespace base {
     14 class DictionaryValue;
     15 class ListValue;
     16 class Value;
     17 }
     18 
     19 namespace chromeos {
     20 namespace onc {
     21 
     22 struct OncValueSignature;
     23 
     24 // This class implements a DeepCopy of base::Values for ONC objects that
     25 // iterates over both the ONC signature and the object hierarchy. DCHECKs if a
     26 // field signature without value signature or an array signature without entry
     27 // signature is reached.
     28 //
     29 // The general term "map" is used here, as this class is meant as base class and
     30 // the copy behavior can be adapted by overriding the methods. By comparing the
     31 // address of a signature object to the list of signatures in "onc_signature.h",
     32 // accurate signature-specific translations or validations can be applied in the
     33 // overriding methods.
     34 //
     35 // The ONC validator and normalizer derive from this class and adapt the default
     36 // copy behavior.
     37 class CHROMEOS_EXPORT Mapper {
     38  public:
     39   Mapper();
     40   virtual ~Mapper();
     41 
     42  protected:
     43   // Calls |MapObject|, |MapArray| and |MapPrimitive| according to |onc_value|'s
     44   // type, which always return an object of the according type. Result of the
     45   // mapping is returned. Only on error sets |error| to true.
     46   virtual scoped_ptr<base::Value> MapValue(const OncValueSignature& signature,
     47                                            const base::Value& onc_value,
     48                                            bool* error);
     49 
     50   // Maps objects/dictionaries. By default calls |MapFields|, which recurses
     51   // into each field of |onc_object|, and drops unknown fields. Result of the
     52   // mapping is returned. Only on error sets |error| to true. In this
     53   // implementation only unknown fields are errors.
     54   virtual scoped_ptr<base::DictionaryValue> MapObject(
     55       const OncValueSignature& signature,
     56       const base::DictionaryValue& onc_object,
     57       bool* error);
     58 
     59   // Maps primitive values like BinaryValue, StringValue, IntegerValue... (all
     60   // but dictionaries and lists). By default copies |onc_primitive|. Result of
     61   // the mapping is returned. Only on error sets |error| to true.
     62   virtual scoped_ptr<base::Value> MapPrimitive(
     63       const OncValueSignature& signature,
     64       const base::Value& onc_primitive,
     65       bool* error);
     66 
     67   // Maps each field of the given |onc_object| according to |object_signature|.
     68   // Adds the mapping of each field to |result| using |MapField| and drops
     69   // unknown fields by default. Sets |found_unknown_field| to true if this
     70   // dictionary contains any unknown fields. Set |nested_error| to true only if
     71   // nested errors occured.
     72   virtual void MapFields(const OncValueSignature& object_signature,
     73                          const base::DictionaryValue& onc_object,
     74                          bool* found_unknown_field,
     75                          bool* nested_error,
     76                          base::DictionaryValue* result);
     77 
     78   // Maps the value |onc_value| of field |field_name| according to its field
     79   // signature in |object_signature| using |MapValue|. Sets
     80   // |found_unknown_field| to true and returns NULL if |field_name| cannot be
     81   // found in |object_signature|. Otherwise returns the mapping of |onc_value|.
     82   virtual scoped_ptr<base::Value> MapField(
     83       const std::string& field_name,
     84       const OncValueSignature& object_signature,
     85       const base::Value& onc_value,
     86       bool* found_unknown_field,
     87       bool* error);
     88 
     89   // Maps the array |onc_array| according to |array_signature|, which defines
     90   // the type of the entries. Maps each entry by calling |MapValue|. If any of
     91   // the nested mappings failed, the flag |nested_error| is set to true and the
     92   // entry is dropped from the result. Otherwise |nested_error| isn't
     93   // modified. The resulting array is returned.
     94   virtual scoped_ptr<base::ListValue> MapArray(
     95       const OncValueSignature& array_signature,
     96       const base::ListValue& onc_array,
     97       bool* nested_error);
     98 
     99   // Calls |MapValue| and returns its result. Called by |MapArray| for each
    100   // entry and its index in the enclosing array.
    101   virtual scoped_ptr<base::Value> MapEntry(int index,
    102                                            const OncValueSignature& signature,
    103                                            const base::Value& onc_value,
    104                                            bool* error);
    105 
    106  private:
    107   DISALLOW_COPY_AND_ASSIGN(Mapper);
    108 };
    109 
    110 }  // namespace onc
    111 }  // namespace chromeos
    112 
    113 #endif  // CHROMEOS_NETWORK_ONC_ONC_MAPPER_H_
    114