Parses the contents of the string data, calling the appropriate
handler functions to process the parsed data. isfinal must be
true on the final call to this method. data can be the empty
string at any time.
ParseFile(
file)
Parse XML data reading from the object file. file only
needs to provide the read(nbytes) method, returning the
empty string when there's no more data.
SetBase(
base)
Sets the base to be used for resolving relative URIs in system
identifiers in declarations. Resolving relative identifiers is left
to the application: this value will be passed through as the
base argument to the ExternalEntityRefHandler,
NotationDeclHandler, and
UnparsedEntityDeclHandler functions.
GetBase(
)
Returns a string containing the base set by a previous call to
SetBase(), or None if
SetBase() hasn't been called.
GetInputContext(
)
Returns the input data that generated the current event as a string.
The data is in the encoding of the entity which contains the text.
When called while an event handler is not active, the return value is
None.
New in version 2.1.
ExternalEntityParserCreate(
context[,
encoding])
Create a ``child'' parser which can be used to parse an external
parsed entity referred to by content parsed by the parent parser. The
context parameter should be the string passed to the
ExternalEntityRefHandler() handler function, described below.
The child parser is created with the ordered_attributes,
returns_unicode and specified_attributes set to the
values of this parser.
UseForeignDTD(
[flag])
Calling this with a true value for flag (the default) will cause
Expat to call the ExternalEntityRefHandler with
None for all arguments to allow an alternate DTD to be
loaded. If the document does not contain a document type declaration,
the ExternalEntityRefHandler will still be called, but the
StartDoctypeDeclHandler and EndDoctypeDeclHandler
will not be called.
Passing a false value for flag will cancel a previous call that
passed a true value, but otherwise has no effect.
This method can only be called before the Parse() or
ParseFile() methods are called; calling it after either of
those have been called causes ExpatError to be raised with
the code attribute set to
errors.XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING.
New in version 2.3.
xmlparser objects have the following attributes:
buffer_size
The size of the buffer used when buffer_text is true. This
value cannot be changed at this time.
New in version 2.3.
buffer_text
Setting this to true causes the xmlparser object to buffer
textual content returned by Expat to avoid multiple calls to the
CharacterDataHandler() callback whenever possible. This can
improve performance substantially since Expat normally breaks
character data into chunks at every line ending. This attribute is
false by default, and may be changed at any time.
New in version 2.3.
buffer_used
If buffer_text is enabled, the number of bytes stored in the
buffer. These bytes represent UTF-8 encoded text. This attribute has
no meaningful interpretation when buffer_text is false.
New in version 2.3.
ordered_attributes
Setting this attribute to a non-zero integer causes the attributes to
be reported as a list rather than a dictionary. The attributes are
presented in the order found in the document text. For each
attribute, two list entries are presented: the attribute name and the
attribute value. (Older versions of this module also used this
format.) By default, this attribute is false; it may be changed at
any time.
New in version 2.1.
returns_unicode
If this attribute is set to a non-zero integer, the handler functions
will be passed Unicode strings. If returns_unicode is
False, 8-bit strings containing UTF-8 encoded data will be
passed to the handlers. This is True by default when
Python is built with Unicode support.
Changed in version 1.6:
Can be changed at any time to affect the result
type.
specified_attributes
If set to a non-zero integer, the parser will report only those
attributes which were specified in the document instance and not those
which were derived from attribute declarations. Applications which
set this need to be especially careful to use what additional
information is available from the declarations as needed to comply
with the standards for the behavior of XML processors. By default,
this attribute is false; it may be changed at any time.
New in version 2.1.
The following attributes contain values relating to the most recent
error encountered by an xmlparser object, and will only have
correct values once a call to Parse() or ParseFile()
has raised a xml.parsers.expat.ExpatError exception.
ErrorByteIndex
Byte index at which an error occurred.
ErrorCode
Numeric code specifying the problem. This value can be passed to the
ErrorString() function, or compared to one of the constants
defined in the errors object.
ErrorColumnNumber
Column number at which an error occurred.
ErrorLineNumber
Line number at which an error occurred.
The following attributes contain values relating to the current parse
location in an xmlparser object. During a callback reporting
a parse event they indicate the location of the first of the sequence
of characters that generated the event. When called outside of a
callback, the position indicated will be just past the last parse
event (regardless of whether there was an associated callback).
New in version 2.4.
CurrentByteIndex
Current byte index in the parser input.
CurrentColumnNumber
Current column number in the parser input.
CurrentLineNumber
Current line number in the parser input.
Here is the list of handlers that can be set. To set a handler on an
xmlparser object o, use
o.handlername = func. handlername must
be taken from the following list, and func must be a callable
object accepting the correct number of arguments. The arguments are
all strings, unless otherwise stated.
XmlDeclHandler(
version, encoding, standalone)
Called when the XML declaration is parsed. The XML declaration is the
(optional) declaration of the applicable version of the XML
recommendation, the encoding of the document text, and an optional
``standalone'' declaration. version and encoding will be
strings of the type dictated by the returns_unicode
attribute, and standalone will be 1 if the document is
declared standalone, 0 if it is declared not to be standalone,
or -1 if the standalone clause was omitted.
This is only available with Expat version 1.95.0 or newer.
New in version 2.1.
Called when Expat begins parsing the document type declaration
(<!DOCTYPE ...). The doctypeName is provided exactly
as presented. The systemId and publicId parameters give
the system and public identifiers if specified, or None if
omitted. has_internal_subset will be true if the document
contains and internal document declaration subset.
This requires Expat version 1.2 or newer.
EndDoctypeDeclHandler(
)
Called when Expat is done parsing the document type declaration.
This requires Expat version 1.2 or newer.
ElementDeclHandler(
name, model)
Called once for each element type declaration. name is the name
of the element type, and model is a representation of the
content model.
AttlistDeclHandler(
elname, attname,
type, default, required)
Called for each declared attribute for an element type. If an
attribute list declaration declares three attributes, this handler is
called three times, once for each attribute. elname is the name
of the element to which the declaration applies and attname is
the name of the attribute declared. The attribute type is a string
passed as type; the possible values are 'CDATA',
'ID', 'IDREF', ...
default gives the default value for the attribute used when the
attribute is not specified by the document instance, or None if
there is no default value (#IMPLIED values). If the attribute
is required to be given in the document instance, required will
be true.
This requires Expat version 1.95.0 or newer.
StartElementHandler(
name, attributes)
Called for the start of every element. name is a string
containing the element name, and attributes is a dictionary
mapping attribute names to their values.
EndElementHandler(
name)
Called for the end of every element.
ProcessingInstructionHandler(
target, data)
Called for every processing instruction.
CharacterDataHandler(
data)
Called for character data. This will be called for normal character
data, CDATA marked content, and ignorable whitespace. Applications
which must distinguish these cases can use the
StartCdataSectionHandler, EndCdataSectionHandler,
and ElementDeclHandler callbacks to collect the required
information.
Called for unparsed (NDATA) entity declarations. This is only present
for version 1.2 of the Expat library; for more recent versions, use
EntityDeclHandler instead. (The underlying function in the
Expat library has been declared obsolete.)
Called for all entity declarations. For parameter and internal
entities, value will be a string giving the declared contents
of the entity; this will be None for external entities. The
notationName parameter will be None for parsed entities,
and the name of the notation for unparsed entities.
is_parameter_entity will be true if the entity is a parameter
entity or false for general entities (most applications only need to
be concerned with general entities).
This is only available starting with version 1.95.0 of the Expat
library.
New in version 2.1.
NotationDeclHandler(
notationName, base,
systemId, publicId)
Called for notation declarations. notationName, base, and
systemId, and publicId are strings if given. If the
public identifier is omitted, publicId will be None.
StartNamespaceDeclHandler(
prefix, uri)
Called when an element contains a namespace declaration. Namespace
declarations are processed before the StartElementHandler is
called for the element on which declarations are placed.
EndNamespaceDeclHandler(
prefix)
Called when the closing tag is reached for an element
that contained a namespace declaration. This is called once for each
namespace declaration on the element in the reverse of the order for
which the StartNamespaceDeclHandler was called to indicate
the start of each namespace declaration's scope. Calls to this
handler are made after the corresponding EndElementHandler
for the end of the element.
CommentHandler(
data)
Called for comments. data is the text of the comment, excluding
the leading `<!--' and trailing `-->'.
StartCdataSectionHandler(
)
Called at the start of a CDATA section. This and
EndCdataSectionHandler are needed to be able to identify
the syntactical start and end for CDATA sections.
EndCdataSectionHandler(
)
Called at the end of a CDATA section.
DefaultHandler(
data)
Called for any characters in the XML document for
which no applicable handler has been specified. This means
characters that are part of a construct which could be reported, but
for which no handler has been supplied.
DefaultHandlerExpand(
data)
This is the same as the DefaultHandler,
but doesn't inhibit expansion of internal entities.
The entity reference will not be passed to the default handler.
NotStandaloneHandler(
)
Called if the
XML document hasn't been declared as being a standalone document.
This happens when there is an external subset or a reference to a
parameter entity, but the XML declaration does not set standalone to
yes in an XML declaration. If this handler returns 0,
then the parser will throw an XML_ERROR_NOT_STANDALONE
error. If this handler is not set, no exception is raised by the
parser for this condition.
ExternalEntityRefHandler(
context, base,
systemId, publicId)
Called for references to external entities. base is the current
base, as set by a previous call to SetBase(). The public and
system identifiers, systemId and publicId, are strings if
given; if the public identifier is not given, publicId will be
None. The context value is opaque and should only be
used as described below.
For external entities to be parsed, this handler must be implemented.
It is responsible for creating the sub-parser using
ExternalEntityParserCreate(context), initializing it with
the appropriate callbacks, and parsing the entity. This handler
should return an integer; if it returns 0, the parser will
throw an XML_ERROR_EXTERNAL_ENTITY_HANDLING error,
otherwise parsing will continue.
If this handler is not provided, external entities are reported by the
DefaultHandler callback, if provided.
