# Custom resolver API
ctypedef enum _InputDocumentDataType:
PARSER_DATA_INVALID
PARSER_DATA_EMPTY
PARSER_DATA_STRING
PARSER_DATA_FILENAME
PARSER_DATA_FILE
@cython.final
@cython.internal
cdef class _InputDocument:
cdef _InputDocumentDataType _type
cdef bytes _data_bytes
cdef object _filename
cdef object _file
cdef bint _close_file
def __cinit__(self):
self._type = PARSER_DATA_INVALID
cdef class Resolver:
"This is the base class of all resolvers."
def resolve(self, system_url, public_id, context):
"""resolve(self, system_url, public_id, context)
Override this method to resolve an external source by
``system_url`` and ``public_id``. The third argument is an
opaque context object.
Return the result of one of the ``resolve_*()`` methods.
"""
return None
def resolve_empty(self, context):
"""resolve_empty(self, context)
Return an empty input document.
Pass context as parameter.
"""
cdef _InputDocument doc_ref
doc_ref = _InputDocument()
doc_ref._type = PARSER_DATA_EMPTY
return doc_ref
def resolve_string(self, string, context, *, base_url=None):
"""resolve_string(self, string, context, base_url=None)
Return a parsable string as input document.
Pass data string and context as parameters. You can pass the
source URL or filename through the ``base_url`` keyword
argument.
"""
cdef _InputDocument doc_ref
if isinstance(string, unicode):
string = (<unicode>string).encode('utf8')
elif not isinstance(string, bytes):
raise TypeError, "argument must be a byte string or unicode string"
doc_ref = _InputDocument()
doc_ref._type = PARSER_DATA_STRING
doc_ref._data_bytes = string
if base_url is not None:
doc_ref._filename = _encodeFilename(base_url)
return doc_ref
def resolve_filename(self, filename, context):
"""resolve_filename(self, filename, context)
Return the name of a parsable file as input document.
Pass filename and context as parameters. You can also pass a
URL with an HTTP, FTP or file target.
"""
cdef _InputDocument doc_ref
doc_ref = _InputDocument()
doc_ref._type = PARSER_DATA_FILENAME
doc_ref._filename = _encodeFilename(filename)
return doc_ref
def resolve_file(self, f, context, *, base_url=None, bint close=True):
"""resolve_file(self, f, context, base_url=None, close=True)
Return an open file-like object as input document.
Pass open file and context as parameters. You can pass the
base URL or filename of the file through the ``base_url``
keyword argument. If the ``close`` flag is True (the
default), the file will be closed after reading.
Note that using ``.resolve_filename()`` is more efficient,
especially in threaded environments.
"""
cdef _InputDocument doc_ref
try:
f.read
except AttributeError:
raise TypeError, "Argument is not a file-like object"
doc_ref = _InputDocument()
doc_ref._type = PARSER_DATA_FILE
if base_url is not None:
doc_ref._filename = _encodeFilename(base_url)
else:
doc_ref._filename = _getFilenameForFile(f)
doc_ref._close_file = close
doc_ref._file = f
return doc_ref
@cython.final
@cython.internal
cdef class _ResolverRegistry:
cdef object _resolvers
cdef Resolver _default_resolver
def __cinit__(self, Resolver default_resolver=None):
self._resolvers = set()
self._default_resolver = default_resolver
def add(self, Resolver resolver not None):
"""add(self, resolver)
Register a resolver.
For each requested entity, the 'resolve' method of the resolver will
be called and the result will be passed to the parser. If this method
returns None, the request will be delegated to other resolvers or the
default resolver. The resolvers will be tested in an arbitrary order
until the first match is found.
"""
self._resolvers.add(resolver)
def remove(self, resolver):
"remove(self, resolver)"
self._resolvers.discard(resolver)
cdef _ResolverRegistry _copy(self):
cdef _ResolverRegistry registry
registry = _ResolverRegistry(self._default_resolver)
registry._resolvers = self._resolvers.copy()
return registry
def copy(self):
"copy(self)"
return self._copy()
def resolve(self, system_url, public_id, context):
"resolve(self, system_url, public_id, context)"
for resolver in self._resolvers:
result = resolver.resolve(system_url, public_id, context)
if result is not None:
return result
if self._default_resolver is None:
return None
return self._default_resolver.resolve(system_url, public_id, context)
def __repr__(self):
return repr(self._resolvers)
@cython.internal
cdef class _ResolverContext(_ExceptionContext):
cdef _ResolverRegistry _resolvers
cdef _TempStore _storage
cdef int clear(self) except -1:
_ExceptionContext.clear(self)
self._storage.clear()
return 0
cdef _initResolverContext(_ResolverContext context,
_ResolverRegistry resolvers):
if resolvers is None:
context._resolvers = _ResolverRegistry()
else:
context._resolvers = resolvers
context._storage = _TempStore()
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