Add support for concatenating var() functions in 'content' declarations

weasyprint/css/computed_values.py

@@ -176,6 +176,46 @@ def decorator(function):
     return decorator
 
 
+def compute_variable(value, name, computed, base_url, parent_style):
+    from .validation.properties import PROPERTIES
+    already_computed_value = False
+
+    if value and isinstance(value, tuple) and value[0] == 'var()':
+        variable_name, default = value[1]
+        computed_value = _resolve_var(computed, variable_name, default)
+        if computed_value is None:
+            new_value = None
+        else:
+            prop = PROPERTIES[name.replace('_', '-')]
+            if prop.wants_base_url:
+                new_value = prop(computed_value, base_url)
+            else:
+                new_value = prop(computed_value)
+
+        # See https://drafts.csswg.org/css-variables/#invalid-variables
+        if new_value is None:
+            try:
+                computed_value = ''.join(
+                    token.serialize() for token in computed_value)
+            except BaseException:
+                pass
+            LOGGER.warning(
+                'Unsupported computed value `%s` set in variable `%s` '
+                'for property `%s`.', computed_value,
+                variable_name.replace('_', '-'), name.replace('_', '-'))
+            if name in INHERITED and parent_style:
+                already_computed_value = True
+                value = parent_style[name]
+            else:
+                already_computed_value = name not in INITIAL_NOT_COMPUTED
+                value = INITIAL_VALUES[name]
+        elif isinstance(new_value, list):
+            value, = new_value
+        else:
+            value = new_value
+    return value, already_computed_value
+
+
 def compute(element, pseudo_type, specified, computed, parent_style,
             root_style, base_url, target_collector):
     """Create a dict of computed values.
@@ -193,7 +233,6 @@ def compute(element, pseudo_type, specified, computed, parent_style,
     :param target_collector: A target collector used to get computed targets.
 
     """
-    from .validation.properties import PROPERTIES
 
     computer = {
         'is_root_element': parent_style is None,
@@ -218,37 +257,19 @@ def compute(element, pseudo_type, specified, computed, parent_style,
         function = getter(name)
         already_computed_value = False
 
-        if value and isinstance(value, tuple) and value[0] == 'var()':
-            variable_name, default = value[1]
-            computed_value = _resolve_var(computed, variable_name, default)
-            if computed_value is None:
-                new_value = None
-            else:
-                prop = PROPERTIES[name.replace('_', '-')]
-                if prop.wants_base_url:
-                    new_value = prop(computed_value, base_url)
-                else:
-                    new_value = prop(computed_value)
-
-            # See https://drafts.csswg.org/css-variables/#invalid-variables
-            if new_value is None:
-                try:
-                    computed_value = ''.join(
-                        token.serialize() for token in computed_value)
-                except BaseException:
-                    pass
-                LOGGER.warning(
-                    'Unsupported computed value `%s` set in variable `%s` '
-                    'for property `%s`.', computed_value,
-                    variable_name.replace('_', '-'), name.replace('_', '-'))
-                if name in INHERITED and parent_style:
-                    already_computed_value = True
-                    value = parent_style[name]
-                else:
-                    already_computed_value = name not in INITIAL_NOT_COMPUTED
-                    value = INITIAL_VALUES[name]
-            else:
-                value = new_value
+        if value:
+            converted_to_list = False
+
+            if not isinstance(value, list):
+                converted_to_list = True
+                value = [value]
+
+            for i, v in enumerate(value):
+                value[i], already_computed_value = \
+                    compute_variable(v, name, computed, base_url, parent_style)
+
+            if converted_to_list:
+                value, = value
 
         if function is not None and not already_computed_value:
             value = function(computer, name, value)

weasyprint/css/utils.py

@@ -699,6 +699,11 @@ def get_content_list_token(token, base_url):
     if string is not None:
         return string
 
+    # <var>
+    var = check_var_function(token)
+    if var is not None:
+        return var
+
     # contents
     if get_keyword(token) == 'contents':
         return ('content', 'text')

weasyprint/css/validation/properties.py

@@ -21,6 +21,7 @@
 PREFIX = '-weasy-'
 PROPRIETARY = set()
 UNSTABLE = set()
+MULTIVAL_PROPERTIES = set()
 
 # Yes/no validators for non-shorthand properties
 # Maps property names to functions taking a property name and a value list,
@@ -33,7 +34,7 @@
 # Validators
 
 def property(property_name=None, proprietary=False, unstable=False,
-             wants_base_url=False):
+             multiple_values=False, wants_base_url=False):
     """Decorator adding a function to the ``PROPERTIES``.
 
     The name of the property covered by the decorated function is set to
@@ -69,6 +70,8 @@ def decorator(function):
             PROPRIETARY.add(name)
         if unstable:
             UNSTABLE.add(name)
+        if multiple_values:
+            MULTIVAL_PROPERTIES.add(name)
         return function
     return decorator
 
@@ -89,10 +92,11 @@ def validate_non_shorthand(base_url, name, tokens, required=False):
     if not required and name not in PROPERTIES:
         raise InvalidValues('property not supported yet')
 
-    for token in tokens:
-        var_function = check_var_function(token)
-        if var_function:
-            return ((name, var_function),)
+    if name not in MULTIVAL_PROPERTIES:
+        for token in tokens:
+            var_function = check_var_function(token)
+            if var_function:
+                return ((name, var_function),)
 
     keyword = get_single_keyword(tokens)
     if keyword in ('initial', 'inherit'):
@@ -454,7 +458,7 @@ def clip(token):
         return ()
 
 
-@property(wants_base_url=True)
+@property(multiple_values=True, wants_base_url=True)
 def content(tokens, base_url):
     """``content`` property validation."""
     # See https://www.w3.org/TR/css-content-3/#content-property

weasyprint/document.py

@@ -12,6 +12,7 @@
 import warnings
 
 import cairocffi as cairo
+
 from weasyprint.layout import LayoutContext
 
 from . import CSS

weasyprint/layout/preferred.py

@@ -718,7 +718,7 @@ def flex_max_content_width(context, box, outer=True):
 
 def trailing_whitespace_size(context, box):
     """Return the size of the trailing whitespace of ``box``."""
-    from .inlines import split_text_box, split_first_line
+    from .inlines import split_first_line, split_text_box
 
     while isinstance(box, (boxes.InlineBox, boxes.LineBox)):
         if not box.children:

weasyprint/tests/test_counters.py

@@ -245,25 +245,29 @@ def test_counters_8():
 def test_counter_styles_1():
     assert_tree(parse_all('''
       <style>
-        body { counter-reset: p -12 }
+        body { --var: 'Counter'; counter-reset: p -12 }
         p { counter-increment: p }
         p:nth-child(1):before { content: '-' counter(p, none) '-'; }
         p:nth-child(2):before { content: counter(p, disc); }
         p:nth-child(3):before { content: counter(p, circle); }
         p:nth-child(4):before { content: counter(p, square); }
         p:nth-child(5):before { content: counter(p); }
+        p:nth-child(6):before { content: var(--var) ':' counter(p); }
+        p:nth-child(7):before { content: counter(p) ':' var(--var); }
       </style>
       <p></p>
       <p></p>
       <p></p>
       <p></p>
       <p></p>
+      <p></p>
+      <p></p>
     '''), [
         ('p', 'Block', [
             ('p', 'Line', [
                 ('p::before', 'Inline', [
                     ('p::before', 'Text', counter)])])])
-        for counter in '--  •  ◦  ◾  -7'.split()])
+        for counter in '--  •  ◦  ◾  -7 Counter:-6 -5:Counter'.split()])
 
 
 @assert_no_logs

weasyprint/tests/test_variables.py

@@ -11,6 +11,8 @@
 from ..css.properties import KNOWN_PROPERTIES
 from .test_boxes import render_pages as parse
 
+SIDES = ('top', 'right', 'bottom', 'left')
+
 
 def test_variable_simple():
     page, = parse('''
@@ -83,6 +85,23 @@ def test_variable_chain():
     assert paragraph.width == 10
 
 
+def test_variable_partial_1():
+    page, = parse('''
+      <style>
+        html { --var: 10px }
+        div { margin: 0 0 0 var(--var) }
+      </style>
+      <div></div>
+    ''')
+    html, = page.children
+    body, = html.children
+    div, = body.children
+    assert div.margin_top == 0
+    assert div.margin_right == 0
+    assert div.margin_bottom == 0
+    assert div.margin_left == 10
+
+
 def test_variable_initial():
     page, = parse('''
       <style>