jinja2/exceptions.py

# -*- coding: utf-8 -*-
"""
    jinja2.exceptions
    ~~~~~~~~~~~~~~~~~

    Jinja exceptions.

    :copyright: (c) 2010 by the Jinja Team.
    :license: BSD, see LICENSE for more details.
"""
import sys
import six
from six.moves import map


class TemplateError(Exception):
    """Baseclass for all template errors."""

    if sys.version_info[0] < 3:
        def __init__(self, message=None):
            if message is not None:
                message = six.text_type(message).encode('utf-8')
            Exception.__init__(self, message)

        @property
        def message(self):
            if self.args:
                message = self.args[0]
                if message is not None:
                    return message.decode('utf-8', 'replace')

    else:
        @property
        def message(self):
            if self.args:
                message = self.args[0]
                if message is not None:
                    return message


class TemplateNotFound(IOError, LookupError, TemplateError):
    """Raised if a template does not exist."""

    # looks weird, but removes the warning descriptor that just
    # bogusly warns us about message being deprecated
    message = None

    def __init__(self, name, message=None):
        IOError.__init__(self)
        if message is None:
            message = name
        self.message = message
        self.name = name
        self.templates = [name]

    def __str__(self):
        return self.message.encode('utf-8')

    # unicode goes after __str__ because we configured 2to3 to rename
    # __unicode__ to __str__.  because the 2to3 tree is not designed to
    # remove nodes from it, we leave the above __str__ around and let
    # it override at runtime.
    def __unicode__(self):
        return self.message


class TemplatesNotFound(TemplateNotFound):
    """Like :class:`TemplateNotFound` but raised if multiple templates
    are selected.  This is a subclass of :class:`TemplateNotFound`
    exception, so just catching the base exception will catch both.

    .. versionadded:: 2.2
    """

    def __init__(self, names=(), message=None):
        if message is None:
            message = u'none of the templates given were found: ' + \
                      u', '.join(map(six.text_type, names))
        TemplateNotFound.__init__(self, names and names[-1] or None, message)
        self.templates = list(names)


class TemplateSyntaxError(TemplateError):
    """Raised to tell the user that there is a problem with the template."""

    def __init__(self, message, lineno, name=None, filename=None):
        TemplateError.__init__(self, message)
        self.lineno = lineno
        self.name = name
        self.filename = filename
        self.source = None

        # this is set to True if the debug.translate_syntax_error
        # function translated the syntax error into a new traceback
        self.translated = False

    def __str__(self):
        s = self.__unicode__()
        return s if six.PY3 else s.encode('utf-8')

    def __unicode__(self):
        # for translated errors we only return the message
        if self.translated:
            return self.message

        # otherwise attach some stuff
        location = 'line %d' % self.lineno
        name = self.filename or self.name
        if name:
            location = 'File "%s", %s' % (name, location)
        lines = [self.message, '  ' + location]

        # if the source is set, add the line to the output
        if self.source is not None:
            try:
                line = self.source.splitlines()[self.lineno - 1]
            except IndexError:
                line = None
            if line:
                lines.append('    ' + line.strip())

        return u'\n'.join(lines)


class TemplateAssertionError(TemplateSyntaxError):
    """Like a template syntax error, but covers cases where something in the
    template caused an error at compile time that wasn't necessarily caused
    by a syntax error.  However it's a direct subclass of
    :exc:`TemplateSyntaxError` and has the same attributes.
    """


class TemplateRuntimeError(TemplateError):
    """A generic runtime error in the template engine.  Under some situations
    Jinja may raise this exception.
    """


class UndefinedError(TemplateRuntimeError):
    """Raised if a template tries to operate on :class:`Undefined`."""


class SecurityError(TemplateRuntimeError):
    """Raised if a template tries to do something insecure if the
    sandbox is enabled.
    """


class FilterArgumentError(TemplateRuntimeError):
    """This error is raised if a filter was called with inappropriate
    arguments
    """