def _is_scaling(self):
""" Return False if ``self.property_name`` does not have default units of ``'px'``.
Test if ``self.css_class`` contains the scaling flag ``-s``. Returns True if ``-s`` is found and
False otherwise.
**Rules:**
- The ``self.property_name`` must possess units of pixels ``'px'``.
- If no property priority is set the encoded ``css_class`` must end with ``-s``.
- If priority is set the encoded ``css_class`` must end with ``-s-i``.
:return: (*bool*) -- Returns True if ``-s`` is found and False otherwise.
**Examples**
>>> scaling_parser = ScalingParser(css_class='font-weight-24-s')
>>> scaling_parser._is_scaling()
True
>>> scaling_parser.css_class = 'font-weight-24-s-i'
>>> scaling_parser._is_scaling()
True
>>> scaling_parser.css_class = 'font-weight-24'
>>> scaling_parser._is_scaling()
False
"""
unit_parser = UnitParser(property_name=self.css_property.name)
if unit_parser.default_units() != 'px':
return False
else:
return self.css_class.endswith(self.scaling_flag) or self.css_class.endswith(self.scaling_flag + '-i')
def test_add_units_margin_top_conversion_True(self):
property_name = 'margin-top'
property_values = ['1', '-20.0', '15px', '60rem']
expected_values = ['0.0625em', '-1.25em', '0.9375em', '60rem']
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=i)
def test_add_units_multi_value_conversion_True_invalid_units(self):
# Expect the values to pass through unchanged.
property_name = 'padding'
property_values = ['1um', '-20.0no', '15txt', '60st']
unit_parser = UnitParser(property_name=property_name)
for value in property_values:
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, value, msg=value)
def test_add_units_UnitLess_Property_conversion_False(self):
property_name = 'font-weight'
property_values = ['bold', '200', '800', 'lighter']
expected_values = ['bold', '200', '800', 'lighter']
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=i)
def test_add_units_multi_value_no_conversion_invalid_units(self):
# Expect the values to pass through unchanged.
property_name = 'padding'
property_values = ['12aou', '-35oeu 15ou', '1ou 2oeu 1ou 2ou', '20i 20u*', '5e 6m 5e 6m']
unit_parser = UnitParser(property_name=property_name)
for value in property_values:
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, value, msg=value)
def test_default_units(self):
property_names = [
'font-size', 'padding', 'margin', 'pitch', 'text-indent', 'volume', 'width', 'font-weight', 'color',
'invalid', '', 'none',
]
expected_units = ['px', 'px', 'px', 'Hz', 'px', '%', 'px', '', '', '', '', '']
for i, property_name in enumerate(property_names):
unit_parser = UnitParser(property_name=property_name)
self.assertEqual(unit_parser.default_units(), expected_units[i])
def test_add_units_multi_value_conversion_True_invalid_pass_through(self):
# Handles cases input like: '1a2', '-35mx 15mx', '1px 2 m11 2', '22.5px 10 22.5px 10'
# Outputs: '1a2', '-35mx 15mx', '0.0625em 0.125em m11 0.125em', '22.5px 0.625em 22.5px 0.625em'
property_name = 'padding'
property_values = ['1a2', '-35mx 15mx', '1px 2 m11 2', '22.5px 10 22.5px 10']
expected_values = ['1a2', '-35mx 15mx', '0.0625em 0.125em m11 0.125em', '1.4062em 0.625em 1.4062em 0.625em']
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=new_value + ' vs ' + expected_values[i])
def test_add_units_margin_top_no_conversion(self):
property_name = 'margin-top'
property_values = ['1', '-20.0', '15px', '60rem']
expected_values = ['1px', '-20.0px', '15px', '60rem']
settings.use_em = False
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=i)
settings.use_em = True
def test_add_units_multi_value_conversion_True_strange_input(self):
# Note that the cm, rem, and em cases are not handled intuitively causing the units to be mixed.
# This still produces valid CSS.
property_name = 'padding'
property_values = ['-35rem 15', '3 4px 3px 5', '5em 6 5em 6', '1em 100 4cm 9rem']
expected_values = [
'-35rem 0.9375em', '0.1875em 0.25em 0.1875em 0.3125em', '5em 0.375em 5em 0.375em', '1em 6.25em 4cm 9rem'
]
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=i)
def test_add_units_multi_value_conversion_True(self):
# Handles cases input like: '12.5', '-35 15', '1 2 1 2', '20% 20%', '5em 6em 5em 6em'
# Outputs: '0.75em', '-35px 15px', '1px 2px 1px 2px', '20% 20%', '5em 6em 5em 6em'
property_name = 'padding'
property_values = ['12', '-35 15', '1 2 1 2', '20% 20%', '5em 6em 5em 6em']
expected_values = [
'0.75em', '-2.1875em 0.9375em', '0.0625em 0.125em 0.0625em 0.125em', '20% 20%', '5em 6em 5em 6em'
]
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=new_value)
def test_add_units_multi_value_no_conversion_strange_input(self):
# Note that the cm, rem and em cases are not handled intuitively causing the units to be mixed.
# This still produces valid CSS.
property_name = 'padding'
property_values = ['-35rem 15', '3 4px 3px 5', '5em 6 5em 6', '1em 100 4cm 9rem']
expected_values = ['-35rem 15px', '3px 4px 3px 5px', '5em 6px 5em 6px', '1em 100px 4cm 9rem']
settings.use_em = False
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=i)
settings.use_em = True
def test_add_units_multi_value_no_conversion(self):
# Handles cases input like: '12', '-35 15', '1 2 1 2'
# Outputs: '12px', '-35px 15px', '1px 2px 1px 2px'
property_name = 'padding'
property_values = ['12', '-35 15', '1 2 1 2', '20% 20%', '5em 6em 5em 6em']
expected_values = ['12px', '-35px 15px', '1px 2px 1px 2px', '20% 20%', '5em 6em 5em 6em']
settings.use_em = False
unit_parser = UnitParser(property_name=property_name)
for i, value in enumerate(property_values):
new_value = unit_parser.add_units(property_value=value)
self.assertEqual(new_value, expected_values[i], msg=i)
settings.use_em = True
def __init__(self, property_name=''):
self.property_name = property_name
self.color_parser = ColorParser(property_name=property_name)
self.unit_parser = UnitParser(property_name=property_name)
class CSSPropertyValueParser(object):
"""
Accepts a ``property_name`` and ``use_em`` unit conversion flag.
Contains multiple parsers and methods that decodes the CSS property_value.
:type property_name: str
:param property_name: A CSS property name.
:return: None
**Attributes:**
**property_name** (*str*) -- A CSS property name. Not allowed to be ``''`` or None.
**color_parser** (*ColorParser*) -- Parses encoded color values.
**unit_parser** (*UnitParser*) -- Parses encoded unit values, and handles unit conversion.
**Important note about methods:**
These methods are intended to be called in the order they are defined inside the class.
"""
def __init__(self, property_name=''):
self.property_name = property_name
self.color_parser = ColorParser(property_name=property_name)
self.unit_parser = UnitParser(property_name=property_name)
def is_built_in(self, value=''):
""" Checks if the encoded ``value`` identically matches a value built-in to the CSS standard.
Returns True if ``value`` matches a CSS built-in valued and False if it does not.
Examples include: 'bold', 'italic', 'w-resize', 'arial', etc.
:type value: str
:param value: Encoded CSS property value.
:return: (*bool*)
- Returns ``True`` if ``value`` matches a CSS built-in valued and ``False`` if it does not.
- The values 'bold', 'italic', 'w-resize', 'arial' all return ``True``.
- The values '-bold', 'fw-', 'color-' all return ``False``.
- Invalid ``self.property_name`` also returns ``False`` (KeyError Case).
**Examples:**
>>> value_parser = CSSPropertyValueParser(
>>> property_name='font-weight', use_em=True
>>> )
>>> value_parser.is_built_in('bold')
True
>>> value_parser = CSSPropertyValueParser(
>>> property_name='padding', use_em=True
>>> )
>>> value_parser.is_built_in('7-4-7-4')
False
>>> value_parser = CSSPropertyValueParser(
>>> property_name='InvalidCSSPropertyName', use_em=True
>>> )
>>> value_parser.is_built_in('italic')
False
"""
if value.startswith('-') or value.endswith('-'):
return False
try:
aliases = property_alias_dict[self.property_name]
return True if value in aliases else False
except KeyError:
return False
@staticmethod
def replace_dashes(value=''):
""" Remove leading and trailing dashes. Replace internal dashes with spaces. Return the modified value.
``-`` becomes either ``''`` or ``' '``.
:type value: str
:param value: Encoded CSS property value.
:return: (*str*) -- Return the value with dashes removed if necessary.
>>> # Delete leading dash '-bold' --> 'bold'
>>> value_parser = CSSPropertyValueParser(
>>> property_name='font-weight', use_em=True
>>> )
>>> value_parser.replace_dashes('-bold')
'bold'
>>> #
>>> # Delete trailing 'white-' --> 'white'
>>> value_parser = CSSPropertyValueParser(
>>> property_name='color', use_em=True
>>> )
>>> value_parser.replace_dashes('white-')
'white'
>>> #
>>> # Replace internal '1-5-1-5' --> '1 5 1 5'
>>> value_parser = CSSPropertyValueParser(
>>> property_name='padding', use_em=True
>>> )
>>> value_parser.replace_dashes('1-5-1-5')
'1 5 1 5'
"""
value = value[1:] if value.startswith('-') else value
value = value[:-1] if value.endswith('-') else value
return value.replace('-', ' ')
@staticmethod
def replace_underscore_with_decimal(value=''):
""" Replace underscore with decimal point. Underscores are used to encode a decimal point
``'_'`` becomes ``'.'``
:type value: str
:param value: Encoded CSS property value.
:return: (*str*) -- Return the value with decimal points added if necessary.
**Example**
>>> value_parser = CSSPropertyValueParser(
>>> property_name='padding', use_em=True
>>> )
>>> value_parser.replace_underscore_with_decimal('1_32rem')
'1.32rem'
"""
if contains_a_digit(string=value):
value = value.replace('_', '.')
return value
@staticmethod
def replace_p_with_percent(value=''):
""" Replace ``'p'`` suffix with ``'%'`` if found at the end of any substring containing digits.
``'p '`` becomes ``'%'``
Mind the space
:type value: str
:param value: Encoded CSS property value.
:return: (*str*) -- Return the value with percent signs added if necessary.
**Example:**
>>> # Multi-value: '1p 10p 3p 1p' --> '1% 10% 3% 1%'
>>> value_parser = CSSPropertyValueParser(
>>> property_name='padding', use_em=True
>>> )
>>> value_parser.replace_p_with_percent(value='1p 10p 3p 1p')
'1% 10% 3% 1%'
>>> #
>>> # Single value ' 1p' --> ' 1%'
>>> value_parser = CSSPropertyValueParser(
>>> property_name='padding', use_em=True
>>> )
>>> value_parser.replace_p_with_percent(value=' 1p')
' 1%'
"""
if contains_a_digit(string=value):
value = value.replace('p ', '% ')
if value.endswith('p'):
value = value[:-1] + '%' # chop last character and add percentage sign
return value
@staticmethod
def replace_n_with_minus(value=''):
""" If a space plus the letter ``' n'`` is immediately followed by a digit replace it with ``' -'``.
If ``n`` is the first letter of the string and followed by digits replace it with ``-``.
The letter ``n`` is an encoding for a negative sign. Leaves other ``n's`` unmodified.
| ``' n2'`` becomes ``' -2'`` Mind the space.
| ``'n5'`` becomes ``'-5'``
:type value: str
:param value: Encoded CSS property value.
:return: (*str*) -- Return the value with minus signs added if necessary.
**Example:**
>>> # Multi-value: 'n5cm n6cm' --> '-5cm -6cm'
>>> value_parser = CSSPropertyValueParser(
>>> property_name='padding', use_em=True
>>> )
>>> value_parser.replace_n_with_minus('n5cm n6cm')
'-5cm -6cm'
>>> #
>>> # 'n9in' --> '-9in' (note that the 'n' at the end is not touched)
>>> value_parser.replace_n_with_minus('n9in')
'-9in'
"""
if contains_a_digit(string=value):
value = value.replace(' n', ' -')
if value.startswith('n'):
value = '-' + value[1:] # add minus sign and chop first character
return value
# Put everything together.
def decode_property_value(self, value=''):
"""
Decode the encoded property ``value`` input e.g. 'bold', '1-5-1-5', '1_32rem', '1p-10p-3p-1p', 'n12px',
'n5_25cm-n6_1cm'. Returns parsed, but non-validated CSS property value.
:type value: str
:param value: An encoded CSS property value.
:return: (*str*) -- Returns the decoded, but non-validated CSS property value.
**Examples:**
>>> value_parser = CSSPropertyValueParser(
>>> property_name='padding', use_em=True
>>> )
>>> value_parser.decode_property_value(value='1-5-1-5')
'0.0625em 0.3125em 0.0625em 0.3125em'
>>> value_parser.unit_parser.use_em = False
>>> value_parser.decode_property_value(value='1-5-1-5')
'1px 5px 1px 5px'
"""
# Skip values that are built-in to the CSS standard, and represent the literal property value.
if not self.is_built_in(value=value):
# Apply to all non-built-in values.
value = self.replace_dashes(value=value)
# These only apply if value contains a digit.
value = self.replace_underscore_with_decimal(value=value)
value = self.replace_p_with_percent(value=value)
value = self.replace_n_with_minus(value=value)
# Parse color and units
value = self.color_parser.replace_h_with_hash(value=value)
value = self.color_parser.add_color_parenthetical(value=value)
value = self.unit_parser.add_units(property_value=value)
else:
# Generate web safe font-family fallback strings.
if self.property_name == 'font-family':
font_parser = FontParser(font_value=value)
value = font_parser.generate_fallback_fonts()
return value
@staticmethod
def property_is_valid(name='', value='', priority=''):
""" Detects if a given property name, value, and priority combination is valid. Returns True if the
combination is valid, and false otherwise.
Validation occurs after the property value is decoded.
:param name: CSS property name
:param value: Decoded CSS property value
:param priority: CSS priority designator
:return: (*bool*) -- Returns True if the CSS property name, value, and priority
combination is valid, and false otherwise.
**Examples:**
>>> value_parser = CSSPropertyValueParser()
>>> value_parser.property_is_valid(
>>> name='padding', value='1px', priority=''
>>> )
True
>>> value_parser.property_is_valid(
>>> name='padding', value='invalid', priority=''
>>> )
False
"""
try:
css_property = Property(name=name, value=value, priority=priority)
is_valid = css_property.valid
return is_valid
except SyntaxErr:
return False
