fix #181: allow FilterExpressions in bird tags

Author: benbacardi

src/django_bird/_typing.py

@@ -2,11 +2,14 @@
 
 import sys
 
+from django.template.base import FilterExpression
+
 if sys.version_info >= (3, 12):
     from typing import override as typing_override
 else:
     from typing_extensions import override as typing_override
 
 override = typing_override
 
-TagBits = list[str]
+RawTagBits = list[str]
+TagBits = dict[str, FilterExpression]

src/django_bird/components.py

@@ -22,7 +22,6 @@
 from .conf import app_settings
 from .params import Param
 from .params import Params
-from .params import Value
 from .plugins import pm
 from .staticfiles import Asset
 from .staticfiles import AssetType
@@ -143,9 +142,9 @@ def render(self, context: Context):
             data_attrs = [
                 Param(
                     f"data-bird-{self.component.data_attribute_name}",
-                    Value(True),
+                    True,
                 ),
-                Param("data-bird-id", Value(f'"{self.component.id}-{self.id}"')),
+                Param("data-bird-id", f"{self.component.id}-{self.id}"),
             ]
             self.params.attrs.extend(data_attrs)
 

src/django_bird/params.py

@@ -5,7 +5,8 @@
 from typing import TYPE_CHECKING
 from typing import Any
 
-from django import template
+from django.template.base import FilterExpression
+from django.template.base import VariableDoesNotExist
 from django.template.context import Context
 from django.utils.safestring import SafeString
 from django.utils.safestring import mark_safe
@@ -55,18 +56,21 @@ def render_attrs(self, context: Context) -> SafeString:
     @classmethod
     def from_node(cls, node: BirdNode) -> Params:
         return cls(
-            attrs=[Param.from_bit(bit) for bit in node.attrs],
+            attrs=[Param(key, Value(value)) for key, value in node.attrs.items()],
             props=[],
         )
 
 
 @dataclass
 class Param:
     name: str
-    value: Value
+    value: Value | str | bool
 
     def render_attr(self, context: Context) -> str:
-        value = self.value.resolve(context)
+        if isinstance(self.value, Value):
+            value = self.value.resolve(context, is_attr=True)
+        else:
+            value = self.value
         if value is None:
             return ""
         name = self.name.replace("_", "-")
@@ -75,47 +79,21 @@ def render_attr(self, context: Context) -> str:
         return f'{name}="{value}"'
 
     def render_prop(self, context: Context) -> str | bool | None:
-        return self.value.resolve(context)
-
-    @classmethod
-    def from_bit(cls, bit: str) -> Param:
-        if "=" in bit:
-            name, raw_value = bit.split("=", 1)
-            value = Value(raw_value.strip())
-        else:
-            name, value = bit, Value(True)
-        return cls(name, value)
+        return (
+            self.value.resolve(context) if isinstance(self.value, Value) else self.value
+        )
 
 
 @dataclass
 class Value:
-    raw: str | bool | None
-
-    def resolve(self, context: Context | dict[str, Any]) -> Any:
-        match (self.raw, self.is_quoted):
-            case (None, _):
-                return None
-
-            case (str(raw_str), False) if raw_str == "False":
-                return None
-            case (str(raw_str), False) if raw_str == "True":
-                return True
-
-            case (bool(b), _):
-                return b if b else None
-
-            case (str(raw_str), False):
-                try:
-                    return template.Variable(raw_str).resolve(context)
-                except template.VariableDoesNotExist:
-                    return raw_str
-
-            case (_, True):
-                return str(self.raw)[1:-1]
-
-    @property
-    def is_quoted(self) -> bool:
-        if self.raw is None or isinstance(self.raw, bool):
-            return False
-
-        return self.raw.startswith(("'", '"')) and self.raw.endswith(self.raw[0])
+    raw: FilterExpression
+
+    def resolve(self, context: Context | dict[str, Any], is_attr=False) -> Any:
+        if is_attr and self.raw.token == "False":
+            return None
+        if self.raw.is_var:
+            try:
+                self.raw.var.resolve(context)
+            except VariableDoesNotExist:
+                return self.raw.token
+        return self.raw.resolve(context)

src/django_bird/templatetags/tags/bird.py

@@ -9,6 +9,7 @@
 from django.template.base import Token
 from django.template.context import Context
 
+from django_bird._typing import RawTagBits
 from django_bird._typing import TagBits
 from django_bird._typing import override
 
@@ -23,7 +24,7 @@ def do_bird(parser: Parser, token: Token) -> BirdNode:
         raise template.TemplateSyntaxError(msg)
 
     name = bits.pop(0)
-    attrs: TagBits = []
+    attrs: TagBits = {}
     isolated_context = False
 
     for bit in bits:
@@ -33,13 +34,18 @@ def do_bird(parser: Parser, token: Token) -> BirdNode:
             case "/":
                 continue
             case _:
-                attrs.append(bit)
+                if "=" in bit:
+                    key, value = bit.split("=")
+                else:
+                    key = bit
+                    value = "True"
+                attrs[key] = parser.compile_filter(value)
 
     nodelist = parse_nodelist(bits, parser)
     return BirdNode(name, attrs, nodelist, isolated_context)
 
 
-def parse_nodelist(bits: TagBits, parser: Parser) -> NodeList | None:
+def parse_nodelist(bits: RawTagBits, parser: Parser) -> NodeList | None:
     # self-closing tag
     # {% bird name / %}
     if len(bits) > 0 and bits[-1] == "/":
@@ -55,7 +61,7 @@ class BirdNode(template.Node):
     def __init__(
         self,
         name: str,
-        attrs: TagBits,
+        attrs: dict[str, str],
         nodelist: NodeList | None,
         isolated_context: bool = False,
     ) -> None:

src/django_bird/templatetags/tags/prop.py

@@ -4,6 +4,7 @@
 from typing import final
 
 from django import template
+from django.template.base import FilterExpression
 from django.template.base import Parser
 from django.template.base import Token
 from django.template.context import Context
@@ -14,7 +15,7 @@
 TAG = "bird:prop"
 
 
-def do_prop(_parser: Parser, token: Token) -> PropNode:
+def do_prop(parser: Parser, token: Token) -> PropNode:
     _tag, *bits = token.split_contents()
     if not bits:
         msg = f"{TAG} tag requires at least one argument"
@@ -26,14 +27,14 @@ def do_prop(_parser: Parser, token: Token) -> PropNode:
         name, default = prop.split("=")
     except ValueError:
         name = prop
-        default = None
+        default = "None"
 
-    return PropNode(name, default, bits)
+    return PropNode(name, parser.compile_filter(default), bits)
 
 
 @final
 class PropNode(template.Node):
-    def __init__(self, name: str, default: str | None, attrs: TagBits):
+    def __init__(self, name: str, default: FilterExpression, attrs: TagBits):
         self.name = name
         self.default = default
         self.attrs = attrs

tests/templatetags/test_bird.py

@@ -53,12 +53,12 @@ def test_missing_name_do_bird(self):
     @pytest.mark.parametrize(
         "params,expected_attrs",
         [
-            ('class="btn"', ['class="btn"']),
-            ("class='btn'", ["class='btn'"]),
-            ('class="btn" id="my-btn"', ['class="btn"', 'id="my-btn"']),
-            ("disabled", ["disabled"]),
-            ("class=dynamic", ["class=dynamic"]),
-            ("class=item.name id=user.id", ["class=item.name", "id=user.id"]),
+            ('class="btn"', {"class": '"btn"'}),
+            ("class='btn'", {"class": "'btn'"}),
+            ('class="btn" id="my-btn"', {"class": '"btn"', "id": '"my-btn"'}),
+            ("disabled", {"disabled": "True"}),
+            ("class=dynamic", {"class": "dynamic"}),
+            ("class=item.name id=user.id", {"class": "item.name", "id": "user.id"}),
         ],
     )
     def test_attrs_do_bird(self, params, expected_attrs):
@@ -69,7 +69,9 @@ def test_attrs_do_bird(self, params, expected_attrs):
 
         node = do_bird(parser, start_token)
 
-        assert node.attrs == expected_attrs
+        for key, value in node.attrs.items():
+            assert key in expected_attrs
+            assert expected_attrs[key] == value.token
 
     @pytest.mark.parametrize(
         "test_case",

tests/templatetags/test_prop.py

@@ -24,8 +24,9 @@ def test_do_prop(contents, expected):
     node = do_prop(Parser([]), start_token)
 
     assert node.name == expected.name
-    assert node.default == expected.default
-    assert node.attrs == expected.attrs
+    assert (node.default.token if node.default else node.default) == expected.default
+    for node_attr, expected_attr in zip(node.attrs, expected.attrs, strict=False):
+        assert node_attr.token == expected_attr
 
 
 def test_do_prop_no_args():

tests/test_params.py

@@ -121,26 +121,6 @@ def test_render_attr(self, param, context, expected):
     def test_render_prop(self, param, context, expected):
         assert param.render_prop(context) == expected
 
-    @pytest.mark.parametrize(
-        "bit,expected",
-        [
-            ("class='btn'", Param(name="class", value=Value("'btn'"))),
-            ('class="btn"', Param(name="class", value=Value('"btn"'))),
-            ("class=btn", Param(name="class", value=Value("btn"))),
-            ("disabled", Param(name="disabled", value=Value(True))),
-            (
-                "class=item.name",
-                Param(name="class", value=Value("item.name")),
-            ),
-            (
-                'class="item.name"',
-                Param(name="class", value=Value('"item.name"')),
-            ),
-        ],
-    )
-    def test_from_bit(self, bit, expected):
-        assert Param.from_bit(bit) == expected
-
 
 class TestParams:
     @pytest.mark.parametrize(
@@ -269,11 +249,11 @@ def test_render_attrs(self, params, context, expected):
         "attrs,expected",
         [
             (
-                ['class="btn"'],
+                {"class": '"btn"'},
                 Params(attrs=[Param(name="class", value=Value('"btn"'))]),
             ),
             (
-                ['class="btn"', 'id="my-btn"'],
+                {"class": '"btn"', "id": '"my-btn"'},
                 Params(
                     attrs=[
                         Param(name="class", value=Value('"btn"')),
@@ -282,15 +262,15 @@ def test_render_attrs(self, params, context, expected):
                 ),
             ),
             (
-                ["disabled"],
+                {"disabled": True},
                 Params(attrs=[Param(name="disabled", value=Value(True))]),
             ),
             (
-                ["class=dynamic"],
+                {"class": "dynamic"},
                 Params(attrs=[Param(name="class", value=Value("dynamic"))]),
             ),
             (
-                ["class=item.name", "id=user.id"],
+                {"class": "item.name", "id": "user.id"},
                 Params(
                     attrs=[
                         Param(name="class", value=Value("item.name")),