// ContentIdList.h

#ifndef ContentIdList_H
#define ContentIdList_H

// David Adams
// June 2002
//
// Ordered list of content ID's.
//
// XML format:
//
// ContentIdList
//   ContentId
//     name = Myclass
//     key = mykey
//   ContentId
//     name = AnotherClass
//     key = another_key
//

#include <set>
#include <iosfwd>
#include "dataset_id/ContentId.h"

class XmlElement;

class ContentIdList : public std::set<ContentId> {

public:  // static methods.

  // XML name.
  static const char* xml_name() { return "ContentIdList"; }

  // XML DTD.
  static const Text& dtd();

public: // methods

  // Default constructor.
  ContentIdList();

  // Constructor from xml.
  // If try_children is true, then the children of the XML element will
  // be searched for a list. The corresponding child will be used if there
  // is exactly one match.
  explicit ContentIdList(const XmlElement& ele, bool try_children =false);

  // Keep only elements that are in the provided list.
  // The size of the new list is returned.
  ContentIdList::size_type select(const ContentIdList& cids);

  // Return if the list contains a content ID.
  bool contains(ContentId cid) const;

  // Return if the list contains another list.
  bool contains(const ContentIdList& cids) const;

  // Write to xml.
  const XmlElement* xml() const;

  // Output stream.
  std::ostream& ostr(std::ostream& lhs, std::string indent) const;

};

// Output stream.
std::ostream& operator<<(std::ostream& lhs, const ContentIdList& rhs);

#endif