Enable Flex declarations

Author: goanpeca

colosseum/declaration.py

@@ -1,5 +1,4 @@
-from . import engine as css_engine
-from . import parser
+from . import engine as css_engine, parser
 from .constants import (  # noqa
     ALIGN_CONTENT_CHOICES, ALIGN_ITEMS_CHOICES, ALIGN_SELF_CHOICES, AUTO,
     BACKGROUND_COLOR_CHOICES, BORDER_COLLAPSE_CHOICES, BORDER_COLOR_CHOICES,
@@ -15,16 +14,19 @@
     NOWRAP, ORDER_CHOICES, ORPHANS_CHOICES, OUTLINE_COLOR_CHOICES,
     OUTLINE_STYLE_CHOICES, OUTLINE_WIDTH_CHOICES, OVERFLOW_CHOICES,
     PADDING_CHOICES, PAGE_BREAK_AFTER_CHOICES, PAGE_BREAK_BEFORE_CHOICES,
-    PAGE_BREAK_INSIDE_CHOICES, POSITION_CHOICES, QUOTES_CHOICES, ROW,
-    SEPARATE, SHOW, SIZE_CHOICES, STATIC, STRETCH, TABLE_LAYOUT_CHOICES,
+    PAGE_BREAK_INSIDE_CHOICES, POSITION_CHOICES, QUOTES_CHOICES, ROW, SEPARATE,
+    SHOW, SIZE_CHOICES, STATIC, STRETCH, TABLE_LAYOUT_CHOICES,
     TEXT_ALIGN_CHOICES, TEXT_DECORATION_CHOICES, TEXT_INDENT_CHOICES,
     TEXT_TRANSFORM_CHOICES, TOP, TRANSPARENT, UNICODE_BIDI_CHOICES,
     VISIBILITY_CHOICES, VISIBLE, WHITE_SPACE_CHOICES, WIDOWS_CHOICES,
     WORD_SPACING_CHOICES, Z_INDEX_CHOICES, OtherProperty,
     TextAlignInitialValue, default,
 )
 from .exceptions import ValidationError
-from .wrappers import Border, BorderBottom, BorderLeft, BorderRight, BorderTop, Outline
+from .wrappers import (  # noqa
+    Border, BorderBottom, BorderLeft, BorderRight, BorderTop, Flex, FlexFlow,
+    Outline
+)
 
 _CSS_PROPERTIES = set()
 
@@ -424,36 +426,36 @@ def __init__(self, **style):
 
     # 5. Ordering and orientation ########################################
     # 5.1 Flex flow direction
-    # flex_direction = validated_property('flex_direction', choices=FLEX_DIRECTION_CHOICES, initial=ROW)
+    flex_direction = validated_property('flex_direction', choices=FLEX_DIRECTION_CHOICES, initial=ROW)
 
     # 5.2 Flex line wrapping
-    # flex_wrap = validated_property('flex_wrap', choices=FLEX_WRAP_CHOICES, initial=NOWRAP)
+    flex_wrap = validated_property('flex_wrap', choices=FLEX_WRAP_CHOICES, initial=NOWRAP)
 
     # 5.3 Flex direction and wrap
-    # flex_flow =
+    flex_flow = validated_shorthand_property('flex_flow', parser=parser.flex_flow, wrapper=FlexFlow)
 
     # 5.4 Display order
-    # order = validated_property('order', choices=ORDER_CHOICES, initial=0)
+    order = validated_property('order', choices=ORDER_CHOICES, initial=0)
 
     # 7. Flexibility #####################################################
     # 7.2 Components of flexibility
-    # flex_grow = validated_property('flex_grow', choices=FLEX_GROW_CHOICES, initial=0)
-    # flex_shrink = validated_property('flex_shrink', choices=FLEX_SHRINK_CHOICES, initial=1)
-    # flex_basis = validated_property('flex_basis', choices=FLEX_BASIS_CHOICES, initial=AUTO)
+    flex_grow = validated_property('flex_grow', choices=FLEX_GROW_CHOICES, initial=0)
+    flex_shrink = validated_property('flex_shrink', choices=FLEX_SHRINK_CHOICES, initial=1)
+    flex_basis = validated_property('flex_basis', choices=FLEX_BASIS_CHOICES, initial=AUTO)
 
     # 7.1 The 'flex' shorthand
-    # flex =
+    flex = validated_shorthand_property('flex', parser=parser.flex, wrapper=Flex)
 
     # 8. Alignment #######################################################
     # 8.2 Axis alignment
-    # justify_content = validated_property('justify_content', choices=JUSTIFY_CONTENT_CHOICES, initial=FLEX_START)
+    justify_content = validated_property('justify_content', choices=JUSTIFY_CONTENT_CHOICES, initial=FLEX_START)
 
     # 8.3 Cros-axis alignment
-    # align_items = validated_property('align_items', choices=ALIGN_ITEMS_CHOICES, initial=STRETCH)
-    # align_self = validated_property('align_self', choices=ALIGN_SELF_CHOICES, initial=AUTO)
+    align_items = validated_property('align_items', choices=ALIGN_ITEMS_CHOICES, initial=STRETCH)
+    align_self = validated_property('align_self', choices=ALIGN_SELF_CHOICES, initial=AUTO)
 
     # 8.4 Packing flex lines
-    # align_content = validated_property('align_content', choices=ALIGN_CONTENT_CHOICES, initial=STRETCH)
+    align_content = validated_property('align_content', choices=ALIGN_CONTENT_CHOICES, initial=STRETCH)
 
     ######################################################################
     # Grid properties

colosseum/parser.py

@@ -369,3 +369,128 @@ def border_bottom(value):
 def border_top(value):
     """Parse border string into a dictionary of outline properties."""
     return border(value, direction='top')
+
+
+##############################################################################
+# Flex Flow
+##############################################################################
+def _parse_flex_flow_property_part(value, flex_flow_dict):
+    """Parse flex_flow shorthand property part for known properties."""
+    from .constants import FLEX_DIRECTION_CHOICES, FLEX_WRAP_CHOICES
+
+    property_validators = {
+        'flex_direction': FLEX_DIRECTION_CHOICES,
+        'flex_wrap': FLEX_WRAP_CHOICES,
+    }
+
+    for property_name, choices in property_validators.items():
+        try:
+            value = choices.validate(value)
+        except (ValueError, ValidationError):
+            continue
+
+        if property_name in flex_flow_dict:
+            raise ValueError('Invalid duplicated property!')
+
+        flex_flow_dict[property_name] = value
+        return flex_flow_dict
+
+    raise ValueError('Flex flow value "{value}" not valid!'.format(value=value))
+
+
+def flex_flow(value):
+    """
+    Parse flex flow string into a dictionary of properties.
+
+    The font CSS property is a shorthand for flex-wrap and flex-direction.
+
+    Reference:
+    - https://www.w3.org/TR/css-flexbox-1/#flex-flow-property
+    """
+    if value:
+        if isinstance(value, str):
+            values = [val.strip() for val in value.split()]
+        elif isinstance(value, Sequence):
+            values = value
+        else:
+            raise ValueError('Unknown flex flow %s ' % value)
+    else:
+        raise ValueError('Unknown flex flow %s ' % value)
+
+    # We iteratively split by the first left hand space found and try to validate if that part
+    # is a valid <flex-wrap> or <flex-direction> (which can come in any order)
+
+    # We use this dictionary to store parsed values and check that values properties are not
+    # duplicated
+    flex_flow_dict = {}
+    for idx, part in enumerate(values):
+        if idx > 1:
+            # Flex flow can have a maximum of 2 parts
+            raise ValueError('Flex flow property shorthand contains too many parts!')
+
+        flex_flow_dict = _parse_flex_flow_property_part(part, flex_flow_dict)
+
+    return flex_flow_dict
+
+
+##############################################################################
+# Flex
+##############################################################################
+def _parse_flex_property_part(value, flex_dict):
+    """Parse flex shorthand property part for known properties."""
+    from .constants import FLEX_GROW_CHOICES, FLEX_SHRINK_CHOICES, FLEX_BASIS_CHOICES
+
+    property_validators = {
+        'flex_grow': FLEX_GROW_CHOICES,
+        'flex_shrink': FLEX_SHRINK_CHOICES,
+        'flex_basis': FLEX_BASIS_CHOICES,
+    }
+
+    for property_name, choices in property_validators.items():
+        try:
+            value = choices.validate(value)
+        except (ValueError, ValidationError):
+            continue
+
+        if property_name in flex_dict:
+            raise ValueError('Invalid duplicated property!')
+
+        flex_dict[property_name] = value
+        return flex_dict
+
+    raise ValueError('Flex value "{value}" not valid!'.format(value=value))
+
+
+def flex(value):
+    """
+    Parse flex string into a dictionary of properties.
+
+    The font CSS property is a shorthand for flex-grow, flex-shrink and flex-basis.
+
+    Reference:
+    - https://www.w3.org/TR/css-flexbox-1/#flex-property
+    """
+    if value:
+        if isinstance(value, str):
+            values = [val.strip() for val in value.split()]
+        elif isinstance(value, Sequence):
+            values = value
+        else:
+            raise ValueError('Unknown flex flow %s ' % value)
+    else:
+        raise ValueError('Unknown flex flow %s ' % value)
+
+    # We iteratively split by the first left hand space found and try to validate if that part
+    # is a valid <flex-grow> or <flex-shrink> or <flex-basis> (which can come in any order)
+
+    # We use this dictionary to store parsed values and check that values properties are not
+    # duplicated
+    flex_dict = {}
+    for idx, part in enumerate(values):
+        if idx > 2:
+            # Flex can have a maximum of 3 parts
+            raise ValueError('Flex property shorthand contains too many parts!')
+
+        flex_dict = _parse_flex_property_part(part, flex_dict)
+
+    return flex_dict

colosseum/wrappers.py

@@ -114,7 +114,7 @@ def __repr__(self):
 
     def __str__(self):
         parts = []
-        for key, value in self.to_dict().items():
+        for __, value in self.to_dict().items():
             parts.append(str(value))
 
         return ' '.join(parts)
@@ -151,3 +151,14 @@ class BorderLeft(Shorthand):
 
 class Border(Shorthand):
     VALID_KEYS = ['border_width', 'border_style', 'border_color']
+
+
+##############################################################################
+# Flex
+##############################################################################
+class FlexFlow(Shorthand):
+    VALID_KEYS = ['flex_direction', 'flex_wrap']
+
+
+class Flex(Shorthand):
+    VALID_KEYS = ['flex_grow', 'flex_shrink', 'flex_basis']