// DatasetCreator.h

#ifndef DatasetCreator_H
#define DatasetCreator_H

// David Adams
// July 2002
//
// Class which creates datasets from XML elements.
// The dataset subclass must be registered before datasets of that
// type are produced.

#include <string>
#include <vector>
#include <iosfwd>
#include "dataset_util/Text.h"

class XmlElement;

namespace dset {

class Dataset;
class DatasetRepository;

class DatasetCreator {

public:  // typedefs

  // Pointer to a function which creates a dataset from an XML element
  // and a database to resolve dataset references.
  typedef
    const Dataset* (*FunPtr) (const XmlElement&, DatasetRepository*);

  // List of class names.
  typedef std::vector<std::string> NameList;

public:  // static functions

  // Register a class.
  // The function pointed to by pfun will called when the an element
  // with name name is encountered.
  // Returns nonzero for error (e.g. same name already used for a
  // differenct function).
  static int insert(std::string name, FunPtr pfun);

  // Create a dataset using the appropriate function.
  // First tries the attribute "fulltype" and then the element name.
  // Caller is responsible for managing (deleting) the dataset.
  // Returns 0 if the element has an unknown name.
  static const Dataset*
    create(const XmlElement& ele, DatasetRepository* prep =0);

  // Return the list of names for which functions have been registered.
  static NameList names();

  // Return if a specified name is registered.
  static bool has(std::string name);

  // Display the names for which functions have been registered.
  static void display(std::ostream& lhs);

};

}  // end namespace dset

#endif