+Options)Parse an XML file. The parser can operate in two input and two output
modes. Output is either a structured term as described with
or call-backs on predefined events. The first is especially suitable for
manipulating not-too-large documents, while the latter provides a
primitive means for handling very large documents.
Input is a stream. A full description of the option-list is below.
- A variable that will be unified with a list describing the content of
the document (see load_structure/2).
- An input stream that is read. This option must be given.
- Stop parsing after Characters. This option is useful to parse
input embedded in envelopes, such as the HTTP protocol.
- Specify the representation of cdata elements. Supported are
atom (default), and
string. See load_structure/3
- Defines how much of the input is parsed. This option is used to parse
only parts of a file.
- Default. Parse everything upto the end of the input.
- The parser stops after reading the first element. Using
source(Stream), this implies reading is stopped as soon as
the element is complete, and another call may be issued on the same
stream to read the next element.
- The value
content is like
element but assumes
the element has already been opened. It may be used in a call-back from
call( to parse individual
elements after validating their headers.
- This may be used to stop the parser after reading the first declaration.
This is especially useful to parse only the
- This option is intended to be used in conjunction with the
allowed(Elements) option of get_sgml_parser/2.
It disables the parser's default to complete the parse-tree by closing
all open elements.
- Set the maximum number of errors. If this number is exceeded further
writes to the stream will yield an I/O error exception. Printing of
errors is suppressed after reaching this value. The default is 50. Using
makes the parser continue, no matter how many errors it encounters.
error(limit_exceeded(max_errors, Max), _)
- Defines how syntax errors are handled.
- Suppress all messages.
- Default. Pass messages to print_message/2.
- Print dubious input such as attempts for redefinitions in the DTD using print_message/2
- Error handling if an XML namespace is not defined. Default generates an
quiet, the error is suppressed. Can be used
call(urlns, Closure) to provide external
expansion of namespaces. See also section
- call(+Event, :PredicateName)
- Issue call-backs on the specified events. PredicateName is
the name of the predicate to call on this event, possibly prefixed with
a module identifier. If the handler throws an exception, parsing is
stopped and sgml_parse/2
re-throws the exception. The defined events are:
- An open-tag has been parsed. The named handler is called with three
Handler(+Tag, +Attributes, +Parser).
- A close-tag has been parsed. The named handler is called with two
- CDATA has been parsed. The named handler is called with two arguments:
Handler(+CDATA, +Parser), where CDATA is an atom
representing the data.
- A processing instruction has been parsed. The named handler is called
with two arguments:
Text is the text of the processing instruction.
- A declaration (
<!...>) has been read. The named
handler is called with two arguments:
+Parser), where Text is the text of the declaration
with comments removed.
This option is expecially useful for highlighting declarations and
comments in editor support, where the location of the declaration is
- An error has been encountered. the named handler is called with three
Handler(+Severity, +Message, +Parser),
Severity is one of
Message is an atom representing the diagnostic message. The
location of the error can be determined using get_sgml_parser/2
If this option is present, errors and warnings are not reported using
- When parsing an in
xmlns mode, a new namespace declaraction
is pushed on the environment. The named handler is called with three
Handler(+NameSpace, +URL, +Parser).
See section 3.3.1 for details.
- When parsing an in
xmlns mode, this predicate can be used
to map a url into either a canonical URL for this namespace or another
internal identifier. See section 3.3.1