libxml++: xmlpp::SaxParser Class Reference

SAX XML parser. More...

#include <libxml++/parsers/saxparser.h>

Inheritance diagram for xmlpp::SaxParser:

Classes

struct  Attribute
 Simple structure used in the start_element callback, in which the attributes are a list of name/value pairs. More...

 
struct  AttributeHasName
 This functor is a helper to find an attribute by name in an AttributeList using the standard algorithm std::find_if. More...

 

Public Types

using AttributeList = std::deque< Attribute >
 
- Public Types inherited from xmlpp::Parser
using size_type = unsigned int
 

Public Member Functions

 SaxParser (bool use_get_entity=false)
 
 ~SaxParser () override
 
void finish_chunk_parsing ()
 Finish a chunk-wise parse. More...

 
void parse_chunk (const Glib::ustring& chunk)
 Parse a chunk of data. More...

 
void parse_chunk_raw (const unsigned char* contents, size_type bytes_count)
 Parse a chunk of data. More...

 
void parse_file (const std::string& filename) override
 Parse an XML document from a file. More...

 
void parse_memory (const Glib::ustring& contents) override
 Parse an XML document from a string. More...

 
void parse_memory_raw (const unsigned char* contents, size_type bytes_count) override
 Parse an XML document from raw memory. More...

 
void parse_stream (std::istream& in) override
 Parse an XML document from a stream. More...

 
- Public Member Functions inherited from xmlpp::Parser
 Parser ()
 
 ~Parser () override
 
bool get_include_default_attributes () noexcept
 See set_include_default_attributes(). More...

 
void get_parser_options (int& set_options, int& clear_options) noexcept
 See set_parser_options(). More...

 
bool get_substitute_entities () const noexcept
 See set_substitute_entities(). More...

 
bool get_throw_messages () const noexcept
 See set_throw_messages(). More...

 
bool get_validate () const noexcept
 See set_validate(). More...

 
void set_include_default_attributes (bool val=true) noexcept
 Set whether default attribute values from the DTD shall be included in the node tree. More...

 
void set_parser_options (int set_options=0, int clear_options=0) noexcept
 Set and/or clear parser option flags. More...

 
void set_substitute_entities (bool val=true) noexcept
 Set whether the parser will automatically substitute entity references with the text of the entities' definitions. More...

 
void set_throw_messages (bool val=true) noexcept
 Set whether the parser will collect and throw error and warning messages. More...

 
void set_validate (bool val=true) noexcept
 By default, the parser will not validate the XML file. More...

 

Protected Member Functions

void initialize_context () override
 
virtual void on_cdata_block (const Glib::ustring& text)
 
virtual void on_characters (const Glib::ustring& characters)
 
virtual void on_comment (const Glib::ustring& text)
 
virtual void on_end_document ()
 
virtual void on_end_element (const Glib::ustring& name)
 
virtual void on_entity_declaration (const Glib::ustring& name, XmlEntityType type, const Glib::ustring& publicId, const Glib::ustring& systemId, const Glib::ustring& content)
 Override this to receive information about every entity declaration. More...

 
virtual void on_error (const Glib::ustring& text)
 
virtual void on_fatal_error (const Glib::ustring& text)
 
virtual _xmlEntity* on_get_entity (const Glib::ustring& name)
 Override this method to resolve entities references in your derived parser, instead of using the default entity resolution, or to be informed when entity references are encountered. More...

 
virtual void on_internal_subset (const Glib::ustring& name, const Glib::ustring& publicId, const Glib::ustring& systemId)
 Override this to receive information about the document's DTD and any entity declarations. More...

 
virtual void on_start_document ()
 
virtual void on_start_element (const Glib::ustring& name, const AttributeList& attributes)
 
virtual void on_warning (const Glib::ustring& text)
 
void release_underlying () override
 
- Protected Member Functions inherited from xmlpp::Parser
virtual void check_for_error_and_warning_messages ()
 
virtual void check_for_exception ()
 
virtual void handle_exception ()
 To be called in an exception handler. More...

 
virtual void on_parser_error (const Glib::ustring& message)
 
virtual void on_parser_warning (const Glib::ustring& message)
 
virtual void on_validity_error (const Glib::ustring& message)
 
virtual void on_validity_warning (const Glib::ustring& message)
 
- Protected Member Functions inherited from xmlpp::NonCopyable
 NonCopyable () noexcept
 
 NonCopyable (const NonCopyable&)=delete
 
 NonCopyable (NonCopyable&&)=delete
 
virtual ~NonCopyable ()
 
NonCopyableoperator= (const NonCopyable&)=delete
 
NonCopyableoperator= (NonCopyable&&)=delete
 

Additional Inherited Members

- Protected Types inherited from xmlpp::Parser
enum  MsgType {

  MsgType::ParserError,

  MsgType::ParserWarning,

  MsgType::ValidityError,

  MsgType::ValidityWarning

}
 
- Static Protected Member Functions inherited from xmlpp::Parser
static void callback_error_or_warning (MsgType msg_type, void* ctx, const char* msg, va_list var_args)
 
static void callback_parser_error (void* ctx, const char* msg,...)
 
static void callback_parser_warning (void* ctx, const char* msg,...)
 
static void callback_validity_error (void* ctx, const char* msg,...)
 
static void callback_validity_warning (void* ctx, const char* msg,...)
 
- Protected Attributes inherited from xmlpp::Parser
_xmlParserCtxt* context_
 
std::unique_ptr< exceptionexception_
 

Detailed Description

SAX XML parser.

Derive your own class and override the on_*() methods. SAX = Simple API for XML

In a system that does not support std::exception_ptr: If an overridden on_*() method throws an exception which is not derived from xmlpp::exception, that exception is replaced by a xmlpp::exception before it is propagated out of the parse method, such as parse_file().

Member Typedef Documentation

Constructor & Destructor Documentation

xmlpp::SaxParser::SaxParser ( bool  use_get_entity = false)
Parameters
use_get_entitySet this to true if you will override on_get_entity(). In theory, if you do not override on_get_entity() the parser should behave exactly the same whether you use true or false here. But the default implementation of on_get_entity(), needed if you override on_get_entity() might not have the same behaviour as the underlying default behaviour of libxml, so the libxml implementation is the default here.
xmlpp::SaxParser::~SaxParser ( )
override

Member Function Documentation

void xmlpp::SaxParser::finish_chunk_parsing ( )

Finish a chunk-wise parse.

Call this after the last call to parse_chunk() or parse_chunk_raw(). Don't use this function with the other parsing methods.

Exceptions
xmlpp::internal_error
xmlpp::parse_error
xmlpp::validity_error
void xmlpp::SaxParser::initialize_context ( )
overrideprotectedvirtual

Reimplemented from xmlpp::Parser.

virtual void xmlpp::SaxParser::on_cdata_block ( const Glib::ustring text)
protectedvirtual
virtual void xmlpp::SaxParser::on_characters ( const Glib::ustring characters)
protectedvirtual
virtual void xmlpp::SaxParser::on_comment ( const Glib::ustring text)
protectedvirtual
virtual void xmlpp::SaxParser::on_end_document ( )
protectedvirtual
virtual void xmlpp::SaxParser::on_end_element ( const Glib::ustring name)
protectedvirtual
virtual void xmlpp::SaxParser::on_entity_declaration ( const Glib::ustring name,
XmlEntityType  type,
const Glib::ustring publicId,
const Glib::ustring systemId,
const Glib::ustring content 
)
protectedvirtual

Override this to receive information about every entity declaration.

If you override this function, and you want normal entity substitution to work, then you must call the base class in your override.

This would be useful when overriding on_get_entity().

Exceptions
xmlpp::internal_error
virtual void xmlpp::SaxParser::on_error ( const Glib::ustring text)
protectedvirtual
virtual void xmlpp::SaxParser::on_fatal_error ( const Glib::ustring text)
protectedvirtual
Exceptions
xmlpp::parse_error
virtual _xmlEntity* xmlpp::SaxParser::on_get_entity ( const Glib::ustring name)
protectedvirtual

Override this method to resolve entities references in your derived parser, instead of using the default entity resolution, or to be informed when entity references are encountered.

If you override this function then you must also specify true for use_get_entity constructor parameter. You will probably need to override on_entity_declaration() as well so that you can use that information when resolving the entity reference.

This is known to be difficult, because it requires both an understanding of the W3C specifications and knowledge of the libxml internals. Entity resolution is easier with the DomParser.

Call this method in this base class for default processing. For instance, if you just want to know about the existence of an entity reference, without affecting the normal substitution, just override and call the base class.

Unlike the DomParser, the SaxParser will also tell you about entity references for the 5 predefined entities.

Parameters
nameThe entity reference name.
Returns
The resolved xmlEntity for the entity reference, or nullptr if not found. You must include libxml/parser.h in order to use this C struct. This instance will not be freed by the caller.
virtual void xmlpp::SaxParser::on_internal_subset ( const Glib::ustring name,
const Glib::ustring publicId,
const Glib::ustring systemId 
)
protectedvirtual

Override this to receive information about the document's DTD and any entity declarations.

virtual void xmlpp::SaxParser::on_start_document ( )
protectedvirtual
virtual void xmlpp::SaxParser::on_start_element ( const Glib::ustring name,
const AttributeList attributes 
)
protectedvirtual
virtual void xmlpp::SaxParser::on_warning ( const Glib::ustring text)
protectedvirtual
void xmlpp::SaxParser::parse_chunk ( const Glib::ustring chunk)

Parse a chunk of data.

This lets you pass a document in small chunks, e.g. from a network connection. The on_* virtual functions are called each time the chunks provide enough information to advance the parser.

The first call to parse_chunk() will setup the parser. When the last chunk has been parsed, call finish_chunk_parsing() to finish the parse.

Parameters
chunkThe next piece of the XML document.
Exceptions
xmlpp::internal_error
xmlpp::parse_error
xmlpp::validity_error
void xmlpp::SaxParser::parse_chunk_raw ( const unsigned char *  contents,
size_type  bytes_count 
)

Parse a chunk of data.

Since libxml++ 2.24:

This lets you pass a document in small chunks, e.g. from a network connection. The on_* virtual functions are called each time the chunks provide enough information to advance the parser.

The first call to parse_chunk_raw() will setup the parser. When the last chunk has been parsed, call finish_chunk_parsing() to finish the parse.

Parameters
contentsThe next piece of the XML document as an array of bytes.
bytes_countThe number of bytes in the contents array.
Exceptions
xmlpp::internal_error
xmlpp::parse_error
xmlpp::validity_error
void xmlpp::SaxParser::parse_file ( const std::string filename)
overridevirtual

Parse an XML document from a file.

Parameters
filenameThe path to the file.
Exceptions
xmlpp::internal_error
xmlpp::parse_error
xmlpp::validity_error

Implements xmlpp::Parser.

void xmlpp::SaxParser::parse_memory ( const Glib::ustring contents)
overridevirtual

Parse an XML document from a string.

Parameters
contentsThe XML document as a string.
Exceptions
xmlpp::internal_error
xmlpp::parse_error
xmlpp::validity_error

Implements xmlpp::Parser.

void xmlpp::SaxParser::parse_memory_raw ( const unsigned char *  contents,
size_type  bytes_count 
)
overridevirtual

Parse an XML document from raw memory.

Parameters
contentsThe XML document as an array of bytes.
bytes_countThe number of bytes in the contents array.
Exceptions
xmlpp::internal_error
xmlpp::parse_error
xmlpp::validity_error

Implements xmlpp::Parser.

void xmlpp::SaxParser::parse_stream ( std::istream in)
overridevirtual

Parse an XML document from a stream.

Parameters
inThe stream.
Exceptions
xmlpp::internal_error
xmlpp::parse_error
xmlpp::validity_error

Implements xmlpp::Parser.

void xmlpp::SaxParser::release_underlying ( )
overrideprotectedvirtual

Reimplemented from xmlpp::Parser.