1 """Different kinds of SAX Exceptions"""

     2 import sys

     3 if sys.platform[:4] == "java":

     4     from java.lang import Exception

     5 del sys

     6 

     7 # ===== SAXEXCEPTION =====

     8 

     9 class SAXException(Exception):

    10     """Encapsulate an XML error or warning. This class can contain

    11     basic error or warning information from either the XML parser or

    12     the application: you can subclass it to provide additional

    13     functionality, or to add localization. Note that although you will

    14     receive a SAXException as the argument to the handlers in the

    15     ErrorHandler interface, you are not actually required to throw

    16     the exception; instead, you can simply read the information in

    17     it."""

    18 

    19     def __init__(self, msg, exception=None):

    20         """Creates an exception. The message is required, but the exception

    21         is optional."""

    22         self._msg = msg

    23         self._exception = exception

    24         Exception.__init__(self, msg)

    25 

    26     def getMessage(self):

    27         "Return a message for this exception."

    28         return self._msg

    29 

    30     def getException(self):

    31         "Return the embedded exception, or None if there was none."

    32         return self._exception

    33 

    34     def __str__(self):

    35         "Create a string representation of the exception."

    36         return self._msg

    37 

    38     def __getitem__(self, ix):

    39         """Avoids weird error messages if someone does exception[ix] by

    40         mistake, since Exception has __getitem__ defined."""

    41         raise AttributeError("__getitem__")

    42 

    43 

    44 # ===== SAXPARSEEXCEPTION =====

    45 

    46 class SAXParseException(SAXException):

    47     """Encapsulate an XML parse error or warning.

    48 

    49     This exception will include information for locating the error in

    50     the original XML document. Note that although the application will

    51     receive a SAXParseException as the argument to the handlers in the

    52     ErrorHandler interface, the application is not actually required

    53     to throw the exception; instead, it can simply read the

    54     information in it and take a different action.

    55 

    56     Since this exception is a subclass of SAXException, it inherits

    57     the ability to wrap another exception."""

    58 

    59     def __init__(self, msg, exception, locator):

    60         "Creates the exception. The exception parameter is allowed to be None."

    61         SAXException.__init__(self, msg, exception)

    62         self._locator = locator

    63 

    64         # We need to cache this stuff at construction time.

    65         # If this exception is thrown, the objects through which we must

    66         # traverse to get this information may be deleted by the time

    67         # it gets caught.

    68         self._systemId = self._locator.getSystemId()

    69         self._colnum = self._locator.getColumnNumber()

    70         self._linenum = self._locator.getLineNumber()

    71 

    72     def getColumnNumber(self):

    73         """The column number of the end of the text where the exception

    74         occurred."""

    75         return self._colnum

    76 

    77     def getLineNumber(self):

    78         "The line number of the end of the text where the exception occurred."

    79         return self._linenum

    80 

    81     def getPublicId(self):

    82         "Get the public identifier of the entity where the exception occurred."

    83         return self._locator.getPublicId()

    84 

    85     def getSystemId(self):

    86         "Get the system identifier of the entity where the exception occurred."

    87         return self._systemId

    88 

    89     def __str__(self):

    90         "Create a string representation of the exception."

    91         sysid = self.getSystemId()

    92         if sysid is None:

    93             sysid = "<unknown>"

    94         linenum = self.getLineNumber()

    95         if linenum is None:

    96             linenum = "?"

    97         colnum = self.getColumnNumber()

    98         if colnum is None:

    99             colnum = "?"

   100         return "%s:%s:%s: %s" % (sysid, linenum, colnum, self._msg)

   101 

   102 

   103 # ===== SAXNOTRECOGNIZEDEXCEPTION =====

   104 

   105 class SAXNotRecognizedException(SAXException):

   106     """Exception class for an unrecognized identifier.

   107 

   108     An XMLReader will raise this exception when it is confronted with an

   109     unrecognized feature or property. SAX applications and extensions may

   110     use this class for similar purposes."""

   111 

   112 

   113 # ===== SAXNOTSUPPORTEDEXCEPTION =====

   114 

   115 class SAXNotSupportedException(SAXException):

   116     """Exception class for an unsupported operation.

   117 

   118     An XMLReader will raise this exception when a service it cannot

   119     perform is requested (specifically setting a state or value). SAX

   120     applications and extensions may use this class for similar

   121     purposes."""

   122 

   123 # ===== SAXNOTSUPPORTEDEXCEPTION =====

   124 

   125 class SAXReaderNotAvailable(SAXNotSupportedException):

   126     """Exception class for a missing driver.

   127 

   128     An XMLReader module (driver) should raise this exception when it

   129     is first imported, e.g. when a support module cannot be imported.

   130     It also may be raised during parsing, e.g. if executing an external

   131     program is not permitted."""