Component balxml_base64parser [Package balxml]

Provide push parser for Base64 types. More...

Namespaces
namespace	balxml

---

Detailed Description

Outline

• Purpose
• Classes
• Description
  • Usage

Purpose:

Provide push parser for Base64 types.

Deprecated:

Use bdlde_base64decoder instead.

Classes:

balxml::Base64Parser

push parser for Base64 types

Description:

The balxml::Base64Parser class template provided by this component can be used to parse Base64 characters into one of the supported Base64 types, which are bsl::vector<char> and bsl::string. The TYPE parameter can be one of these two types.

This class template is a model of the PushParser concept, which contains the following methods:

  int beginParse(TYPE *object);
      // Prepare the parser to start parsing a new value and associate the
      // specified 'object' with the parser.  Return 0 if successful and
      // non-zero otherwise.

  int endParse();
      // Ends the parse operation and store the value parsed from the pushed
      // characters into the associated object.  Return 0 if successful and
      // non-zero otherwise.  The behavior is undefined unless an object is
      // associated with this parser.  Upon successful completion, the parser
      // will be disassociated with the object.

  template <typename INPUT_ITERATOR>
  int pushCharacters(INPUT_ITERATOR begin, INPUT_ITERATOR end);
      // Push the characters ranging from the specified 'begin' up to (but
      // not including) the specified 'end' into this parser.  Return 0 if
      // successful and non-zero otherwise.  The parameterized
      // 'INPUT_ITERATOR' must be dereferenceable to a 'char' value.  The
      // behavior is undefined unless an object is associated with this
      // parser.

Usage:

The following snippets of code illustrate the usage of this component. Suppose you had an input stream that contained Base64 data. The following loadFromBase64Stream function loads this data into an bsl::vector<char> blob:

  #include <balxml_base64parser.h>

  #include <istream>
  #include <iterator>
  #include <vector>

  using namespace BloombergLP;

  int loadFromBase64Stream(bsl::vector<char> *result, bsl::istream& stream)
  {
      enum { FAILURE = -1 };

      balxml::Base64Parser<bsl::vector<char> > parser;

      if (0 != parser.beginParse(result)) {
          return FAILURE;
      }

      if (0 != parser.pushCharacters(bsl::istreambuf_iterator<char>(stream),
                                     bsl::istreambuf_iterator<char>())) {
          return FAILURE;
      }

      return parser.endParse();
  }

The following function demonstrates the loadFromBase64Stream function:

  #include <sstream>

  void usageExample()
  {
      const char INPUT[] = "YWJjZA==";  // "abcd" in Base64

      bsl::vector<char>  vec;
      bsl::istringstream iss(INPUT);

      int result = loadFromBase64Stream(&vec, iss);

      assert(0   == result);
      assert(4   == vec.size());
      assert('a' == vec[0]);
      assert('b' == vec[1]);
      assert('c' == vec[2]);
      assert('d' == vec[3]);
  }