#ifndef s11n_S11N_NODE_HPP_INCLUDED #define s11n_S11N_NODE_HPP_INCLUDED //////////////////////////////////////////////////////////////////////// // s11n_node.hpp // A reference implementation for s11n's Data Node concept. // License: Public Domain // Author: stephan@s11n.net //////////////////////////////////////////////////////////////////////// #include #include #include #include // for lexical casting #include namespace s11n { /** s11n_node is a slightly lighter-weight replacement for the data_node type used in s11n 1.0.x. It will become the standard node type for s11nlite in 1.1/1.2. */ class S11N_EXPORT_API s11n_node { public: /** The map type this object uses to store properties. */ typedef std::map < std::string, std::string > map_type; /** A pair type used to store key/value properties internally. */ typedef map_type::value_type value_type; /** The type used to store property keys. For compatibility with std::map. */ typedef map_type::key_type key_type; /** The type used to internally store property values. For compatibility with std::map. */ typedef map_type::mapped_type mapped_type; /** The container type used to store this object's children. It contains (s11n_node *). While the exact type is not guaranteed, it is guaranteed to obey the most-commonly-used std::list/vector conventions: push_back(), erase(), etc. */ typedef std::vector child_list_type; /** Creates a new node with an empty name() and an class_name() of "s11n::s11n_node". This node is functionally useless until it's name is set, as nodes with empty names are not supported by any current i/o parsers. */ s11n_node(); /** Creates a new node with the given name() and an class_name() of "s11n::s11n_node". */ explicit s11n_node( const std::string & name ); /** Creates a new node with the given name() and and class_name(). Does not throw. */ s11n_node( const std::string & name, const std::string implclass ); /** Destroys all child objects owned by this object, freeing up their resources. Does not throw. */ ~s11n_node(); /** Swaps all publically-visible internal state with rhs. This includes: - class_name() - name() - children() - properties() Complexity is, in theory, constant time. For all data we use their member swap() implementations, which should be constant-time for the containers. The C++ Standard apparently guarantees O(1) swap() for strings, too. (Josuttis, The C++ Standard Library, section 11.2.8, page 490.) Added in version 1.1.3. */ void swap( s11n_node & rhs ); /** Copies the properties, name, class name and children of rhs. If rhs is this object then this function does nothing. Does not throw. */ s11n_node & operator=( const s11n_node & rhs ); /** See copy(). Does not throw. */ s11n_node( const s11n_node & rhs ); /** Returns a list of the s11n_node children of this object. The caller should not delete any pointers from this list unless he also removes the pointers from the list, or else they will get double-deleted later. In practice it is (almost) never necessary for client code to manipulate this list directly. */ child_list_type & children(); /** The const form of children(). */ const child_list_type & children() const; /** Removes all properties and deletes all children from this object, freeing up their resources. Any pointers to children of this object become invalided by a call to this function (they get deleted). */ void clear(); /** Defines the class name which should be used as the implementation class when this node is deserialize()d. Client Serializable types should call this one time from their serialize() method, after calling the parent class' serialize() method (if indeed that is called at all), passing it the name of their class, using the name expected by the classloader. By convention the class name is the same as it's C++ name, thus Serializable class foo::FooBar should call: 
node.class_name( "foo::FooBar" );
from it's serialize() function. If classes to not set this then the serialized data will not have a proper implementation class name. That is likely to break deserialization. TODO: consider returning the old value, to simplify swap() operations. Added in 1.1.3. */ void class_name( const std::string & n ); /** Returns the implementation class name set via class_name(). */ std::string class_name() const; /** The name which should be used as the key for storing the node. This is normally translated to something like an XML element name (e.g., <name>), and should not contain spaces or other characters which may not be usable as key names. To be safe, stick to alphanumeric and underscores, starting with a letter or underscore. (This class does no enforce any naming conventions, but your data file parsers very well may.) */ void name( const std::string & n ); /** Returns this node's name, as set via name(string). */ std::string name() const; /** Returns true if this object has no properties and no children. The name() and class_name() are *not* considered. */ bool empty() const; /** Lexically casts val to a string and stores it as a property. If this type conversion is not possible it will fail at compile time. A value-conversion failure, on the other hand, is not caught at compile time. T must support complementary ostream<< and istream>> operators. */ template < typename T > void set( const std::string & key, const T & val ) { this->m_map[key] = ::s11n::Detail::variant(val).str(); } /** Tries to get a property named key and lexically cast it to type T. If this type conversion is not possible it will fail at compile time. A value-conversion failure, on the other hand, is not caught at compile time. If value conversion fails, or if the requested property is not set, then defaultval is returned. This can be interpretted as an error value if the client so chooses, and it is often helpful to pass a known-invalid value here for that purpose. */ template < typename T > T get( const std::string & key, const T & defaultval ) const { map_type::const_iterator cit = this->m_map.find( key ); return ( this->m_map.end() == cit ) ? defaultval : ::s11n::Detail::variant( (*cit).second ).cast_to(defaultval); } /** Returns true if this object contains the given property, else false. */ bool is_set( const std::string & key ) const; /** Removes the given property from this object. */ void unset( const std::string & key ); /** Returns the map of properties contained by this node. */ map_type & properties(); /** Const overload. */ const map_type & properties() const; private: std::string m_name; // name of this node std::string m_iname; // class_name name of this node map_type m_map; // stores key/value properties. child_list_type m_children; // holds child pointers /** Copies all properties and child s11n_nodes from rhs into this object, as well as any other details which need to be copied. This can be a very expensive operation, and is rarely necessary. */ void copy( const s11n_node & rhs ); /** Removes all property entries from this object. */ void clear_properties(); /** Removes all children from this object, deleting all child pointers. */ void clear_children(); }; // class s11n_node } // namespace s11n #endif // s11n_S11N_NODE_HPP_INCLUDED