ledger/src/builder.h
2008-04-13 03:38:46 -04:00

83 lines
2.2 KiB
C++

#ifndef _BUILDER_H
#define _BUILDER_H
#include "xml.h"
namespace ledger {
/**
* @class builder_t
*
* @brief Represents an interface for building a data hierarchy.
*
* This interface is much like .NET's XmlWriter facility. It
* abstracts the kind of hierarchy we're building, instead focusing
* only on the relationships.
*/
class builder_t
{
virtual void pushAttribute(const string& name,
const string& value) = 0;
virtual void pushAttribute(const nameid_t name_id,
const string& value) = 0;
virtual void beginNode(const string& name) = 0;
virtual void beginNode(const nameid_t name_id) = 0;
virtual void appendText(const string& text) = 0;
virtual node_t * endNode(const optional<string>& name =
optional<string>()) = 0;
virtual node_t * endNode(const nameid_t name_id) = 0;
};
/**
* @class xml_builder_t
*
* @brief Build a generic node_t hierarchy.
*
* This builder can be used to parse ordinary XML into a document
* object structure which can then be traversed in memory.
*/
class xml_builder_t : public builder_t
{
};
/**
* @class journal_builder_t
*
* @brief This custom builder creates an XML-mirrored Ledger journal.
*
* Rather than simply creating a node_t hierarchy, as xml_builder_t
* does, this code creates the associated journal elements referred to
* by those nodes, and then refers to those elements via minimalist
* "shadow nodes".
*
* Thus, after building a <transaction> element, the element itself
* will have no children, but instead will point to a transaction_t
* object. If later an XPath expression desires to traverse the
* <transaction> element, all of the appropriate child nodes will be
* constructed on the fly, as if they'd been created in the first
* place by a regular xml_builder_t.
*/
class journal_builder_t : public xml_builder_t
{
};
/**
* @class xml_writer_t
*
* @brief Create textual XML on the given output stream.
*
* This builder, rather than manipulating data structures in memory,
* simply streams its contents on the fly to the given output stream.
* It uses only enough memory to remember the currently push
* attributes and text.
*/
class xml_writer_t : public builder_t
{
};
} // namespace ledger
#endif // _BUILDER_H