Python jinja2.runtime.Undefined() Examples

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable is not defined'``. If you want
    to use default with variables that evaluate to false you have to
    set the second parameter to `true`:

    .. sourcecode:: jinja

        {{ ''|default('the string was empty', true) }}
    """
    if isinstance(value, Undefined) or (boolean and not value):
        return default_value
    return value 

def xproto_first_non_empty(lst):
    # Returns the first non-empty element in the list. Empty is interpreted to be either
    # None or the empty string or an instance of jinja2 Undefined(). The value False and the
    # string "False" are not considered empty, but are values.
    for item in lst:
        if (item is not None) and (item != "") and (not isinstance(item, Undefined)):
            return item 

def test_undefined(value):
    """Like :func:`defined` but the other way round."""
    return isinstance(value, Undefined) 

def test_defined(value):
    """Return true if the variable is defined:

    .. sourcecode:: jinja

        {% if variable is defined %}
            value of variable: {{ variable }}
        {% else %}
            variable is not defined
        {% endif %}

    See the :func:`default` filter for a simple way to set undefined
    variables.
    """
    return not isinstance(value, Undefined) 

def test_undefined(value):
    """Like :func:`defined` but the other way round."""
    return isinstance(value, Undefined) 

def is_undefined(obj):
    """Check if the object passed is undefined.  This does nothing more than
    performing an instance check against :class:`Undefined` but looks nicer.
    This can be used for custom filters or tests that want to react to
    undefined variables.  For example a custom default filter can look like
    this::

        def default(var, default=''):
            if is_undefined(var):
                return default
            return var
    """
    from jinja2.runtime import Undefined
    return isinstance(obj, Undefined) 

def do_xmlattr(_eval_ctx, d, autospace=True):
    """Create an SGML/XML attribute string based on the items in a dict.
    All values that are neither `none` nor `undefined` are automatically
    escaped:

    .. sourcecode:: html+jinja

        <ul{{ {'class': 'my_list', 'missing': none,
                'id': 'list-%d'|format(variable)}|xmlattr }}>
        ...
        </ul>

    Results in something like this:

    .. sourcecode:: html

        <ul class="my_list" id="list-42">
        ...
        </ul>

    As you can see it automatically prepends a space in front of the item
    if the filter returned something unless the second parameter is false.
    """
    rv = u' '.join(
        u'%s="%s"' % (escape(key), escape(value))
        for key, value in iteritems(d)
        if value is not None and not isinstance(value, Undefined)
    )
    if autospace and rv:
        rv = u' ' + rv
    if _eval_ctx.autoescape:
        rv = Markup(rv)
    return rv 

def fail_for_missing_callable(string, name):
    msg = string % name
    if isinstance(name, Undefined):
        try:
            name._fail_with_undefined_error()
        except Exception as e:
            msg = '%s (%s; did you forget to quote the callable name?)' % (msg, e)
    raise TemplateRuntimeError(msg) 

def __new__(cls, source,
                block_start_string=BLOCK_START_STRING,
                block_end_string=BLOCK_END_STRING,
                variable_start_string=VARIABLE_START_STRING,
                variable_end_string=VARIABLE_END_STRING,
                comment_start_string=COMMENT_START_STRING,
                comment_end_string=COMMENT_END_STRING,
                line_statement_prefix=LINE_STATEMENT_PREFIX,
                line_comment_prefix=LINE_COMMENT_PREFIX,
                trim_blocks=TRIM_BLOCKS,
                lstrip_blocks=LSTRIP_BLOCKS,
                newline_sequence=NEWLINE_SEQUENCE,
                keep_trailing_newline=KEEP_TRAILING_NEWLINE,
                extensions=(),
                optimized=True,
                undefined=Undefined,
                finalize=None,
                autoescape=False,
                enable_async=False):
        env = get_spontaneous_environment(
            block_start_string, block_end_string, variable_start_string,
            variable_end_string, comment_start_string, comment_end_string,
            line_statement_prefix, line_comment_prefix, trim_blocks,
            lstrip_blocks, newline_sequence, keep_trailing_newline,
            frozenset(extensions), optimized, undefined, finalize, autoescape,
            None, 0, False, None, enable_async)
        return env.from_string(source, template_class=cls) 

def __call__(self, *args, **kwargs):
        context = self._template.new_context(dict(*args, **kwargs))
        consume(self._template.root_render_func(context))
        rv = context.vars['result']
        if self._undefined_to_none and isinstance(rv, Undefined):
            rv = None
        return rv 

def is_undefined(obj):
    """Check if the object passed is undefined.  This does nothing more than
    performing an instance check against :class:`Undefined` but looks nicer.
    This can be used for custom filters or tests that want to react to
    undefined variables.  For example a custom default filter can look like
    this::

        def default(var, default=''):
            if is_undefined(var):
                return default
            return var
    """
    from jinja2.runtime import Undefined
    return isinstance(obj, Undefined) 

def test_xproto_first_non_empty(self):
        self.assertEqual(xproto_first_non_empty(["a"]), "a")
        self.assertEqual(xproto_first_non_empty([None,"a"]), "a")
        self.assertEqual(xproto_first_non_empty([None]), None)
        self.assertEqual(xproto_first_non_empty([]), None)
        self.assertEqual(xproto_first_non_empty([False, True]), False)
        self.assertEqual(xproto_first_non_empty([None, "Foo", True]), "Foo")
        self.assertEqual(xproto_first_non_empty(["", "Foo", True]), "Foo")
        self.assertEqual(xproto_first_non_empty([Undefined(), "Foo", True]), "Foo") 

def is_undefined(obj):
    """Check if the object passed is undefined.  This does nothing more than
    performing an instance check against :class:`Undefined` but looks nicer.
    This can be used for custom filters or tests that want to react to
    undefined variables.  For example a custom default filter can look like
    this::

        def default(var, default=''):
            if is_undefined(var):
                return default
            return var
    """
    from jinja2.runtime import Undefined
    return isinstance(obj, Undefined) 

def __call__(self, *args, **kwargs):
        context = self._template.new_context(dict(*args, **kwargs))
        consume(self._template.root_render_func(context))
        rv = context.vars['result']
        if self._undefined_to_none and isinstance(rv, Undefined):
            rv = None
        return rv 

def __new__(cls, source,
                block_start_string=BLOCK_START_STRING,
                block_end_string=BLOCK_END_STRING,
                variable_start_string=VARIABLE_START_STRING,
                variable_end_string=VARIABLE_END_STRING,
                comment_start_string=COMMENT_START_STRING,
                comment_end_string=COMMENT_END_STRING,
                line_statement_prefix=LINE_STATEMENT_PREFIX,
                line_comment_prefix=LINE_COMMENT_PREFIX,
                trim_blocks=TRIM_BLOCKS,
                lstrip_blocks=LSTRIP_BLOCKS,
                newline_sequence=NEWLINE_SEQUENCE,
                keep_trailing_newline=KEEP_TRAILING_NEWLINE,
                extensions=(),
                optimized=True,
                undefined=Undefined,
                finalize=None,
                autoescape=False,
                enable_async=False):
        env = get_spontaneous_environment(
            block_start_string, block_end_string, variable_start_string,
            variable_end_string, comment_start_string, comment_end_string,
            line_statement_prefix, line_comment_prefix, trim_blocks,
            lstrip_blocks, newline_sequence, keep_trailing_newline,
            frozenset(extensions), optimized, undefined, finalize, autoescape,
            None, 0, False, None, enable_async)
        return env.from_string(source, template_class=cls) 

def fail_for_missing_callable(string, name):
    msg = string % name
    if isinstance(name, Undefined):
        try:
            name._fail_with_undefined_error()
        except Exception as e:
            msg = '%s (%s; did you forget to quote the callable name?)' % (msg, e)
    raise TemplateRuntimeError(msg) 

def do_xmlattr(_eval_ctx, d, autospace=True):
    """Create an SGML/XML attribute string based on the items in a dict.
    All values that are neither `none` nor `undefined` are automatically
    escaped:

    .. sourcecode:: html+jinja

        <ul{{ {'class': 'my_list', 'missing': none,
                'id': 'list-%d'|format(variable)}|xmlattr }}>
        ...
        </ul>

    Results in something like this:

    .. sourcecode:: html

        <ul class="my_list" id="list-42">
        ...
        </ul>

    As you can see it automatically prepends a space in front of the item
    if the filter returned something unless the second parameter is false.
    """
    rv = u' '.join(
        u'%s="%s"' % (escape(key), escape(value))
        for key, value in iteritems(d)
        if value is not None and not isinstance(value, Undefined)
    )
    if autospace and rv:
        rv = u' ' + rv
    if _eval_ctx.autoescape:
        rv = Markup(rv)
    return rv 

def test_undefined(value):
    """Like :func:`defined` but the other way round."""
    return isinstance(value, Undefined) 

def test_defined(value):
    """Return true if the variable is defined:

    .. sourcecode:: jinja

        {% if variable is defined %}
            value of variable: {{ variable }}
        {% else %}
            variable is not defined
        {% endif %}

    See the :func:`default` filter for a simple way to set undefined
    variables.
    """
    return not isinstance(value, Undefined) 

def dollars_filter(x):
    """
    Format as currency using :py:func:`~.utils.fmt_currency`.

    :param x: currency amount, int, float, decimal, etc.
    :return: formatted currency
    :rtype: str
    """
    if x == '' or x is None or isinstance(x, Undefined):
        return ''
    return fmt_currency(x) 

def ago_filter(dt):
    """
    Format a datetime using humanize.naturaltime, "ago"

    :param dt: datetime to compare to now
    :type dt: datetime.datetime
    :return: ago string
    :rtype: str
    """
    if dt == '' or dt is None or isinstance(dt, Undefined):
        return ''
    return naturaltime(dtnow() - dt) 

def __new__(cls, source,
                block_start_string=BLOCK_START_STRING,
                block_end_string=BLOCK_END_STRING,
                variable_start_string=VARIABLE_START_STRING,
                variable_end_string=VARIABLE_END_STRING,
                comment_start_string=COMMENT_START_STRING,
                comment_end_string=COMMENT_END_STRING,
                line_statement_prefix=LINE_STATEMENT_PREFIX,
                line_comment_prefix=LINE_COMMENT_PREFIX,
                trim_blocks=TRIM_BLOCKS,
                lstrip_blocks=LSTRIP_BLOCKS,
                newline_sequence=NEWLINE_SEQUENCE,
                keep_trailing_newline=KEEP_TRAILING_NEWLINE,
                extensions=(),
                optimized=True,
                undefined=Undefined,
                finalize=None,
                autoescape=False):
        env = get_spontaneous_environment(
            block_start_string, block_end_string, variable_start_string,
            variable_end_string, comment_start_string, comment_end_string,
            line_statement_prefix, line_comment_prefix, trim_blocks,
            lstrip_blocks, newline_sequence, keep_trailing_newline,
            frozenset(extensions), optimized, undefined, finalize, autoescape,
            None, 0, False, None)
        return env.from_string(source, template_class=cls)