XML::FSM Class Reference

#include <xml.h>

Public Member Functions
	FSM ()
State	getState ()
const std::string &	getTag ()
void	next (State new_state, const std::string &tag=std::string())
bool	finished ()

Private Member Functions
void	advance (State new_state)

Private Attributes
State	m_state
	Current state. Initialized to NEW.
std::stack< std::string >	m_tags
	Stack of header name tags.
const std::vector< std::array< int, 2 > >	transitions

Detailed Description

XML Finite State Machine. This class used for both input and output to keep track of current state of XML and to make sure the next state is a legal transition

Constructor & Destructor Documentation

XML::FSM::FSM ( )

inline

Default constructor for FSM class. Initialize FSM to state NEW. Only time FSM is in this state.

Member Function Documentation

void XML::FSM::advance ( State  new_state )

private

Check the transition of old state (m_state) => new_state is legal. If legal, m_state is new_state otherwise it is set to illegal.

bool XML::FSM::finished ( )

inline

Check if FSM is finished when last closing footer is encountered.

Returns

True if there no more tags to be processed.

State XML::FSM::getState ( )

inline

Return current state of FSM.

Returns

Current state of FSM.

const std::string& XML::FSM::getTag ( )

inline

Return string with tag last added or next to be processed.

Returns

Return top of tag stack.

void XML::FSM::next	(	State	new_state,
		const std::string &	tag = std::string()
	)

Advance FSM to new_state and check if this is a legal transition. If tag is non-empty it also checked. Either m_state is set to new_state or ILLEGAL.

Parameters

new_state	Expected next state after transition
tag	Expected next tag (may be empty if not relevent).

Member Data Documentation

const std::vector<std::array<int, 2> > XML::FSM::transitions

private

Initial value:

= {
            { NEW,             HEADER                         },
            { ATOM_END|FOOTER, FOOTER|HEADER                  },
            { HEADER,          NAME_VALUE|HEADER_END|ATOM_END },
            { NAME_VALUE,      HEADER_END|ATOM_END|NAME_VALUE },
            { HEADER_END,      ELEMENT|HEADER                 },
            { ELEMENT,         FOOTER                         }
        }

The array transitions implments the following state machine to check XML syntax.

     +---—+      NEW  +-----—+
     ^      |       |   |        |
     |      V       V   V        |
   FOOTER<–+---—>HEADER--—+ |
     ^      ^        |  |      | |
     |      |   +-—+  |  +-+ | |
     |      |   |       |  | | | |
     |      |   V       V  V | | |
     |    ATOM_END<-NAME_VALUE | |
     |                 |       | |
     |                 V       | |
     +–ELEMENT<—HEADER_END<-+ |
                       |         |
                       +------—+

---

The documentation for this class was generated from the following files:

• xml.h
• xml.cpp