Missing context variables and kwargs in component_block (#17)

* Fix issue with missing variables by binding template to context in Component.render method.
* Pass extra_context to Component.render()

Co-authored-by: rbeard0330 <@dul2k3BKW6m>

django_components/component.py

@@ -85,7 +85,9 @@ class Component(with_metaclass(MediaDefiningClass)):
                 else:
                     nodelist.append(node)
 
-            return nodelist.render(Context(context))
+            render_context = Context(context)
+            with render_context.bind_template(template.template):
+                return nodelist.render(render_context)
 
         return template.render(context)
 

django_components/templatetags/component_tags.py

@@ -138,8 +138,8 @@ class ComponentNode(Node):
 
     def render(self, context):
         extra_context = {
-            key: filter_expression.resolve(context)
-            for key, filter_expression in self.extra_context.items()
+            key: context_item.resolve(context) if hasattr(context_item, 'resolve') else context_item
+            for key, context_item in self.extra_context.items()
         }
         context.update(extra_context)
 
@@ -149,7 +149,7 @@ class ComponentNode(Node):
             slots_filled = context.render_context[COMPONENT_CONTEXT_KEY][self.component]
             return self.component.render(slots_filled=slots_filled, **context.flatten())
 
-        return self.component.render()
+        return self.component.render(**extra_context)
 
 
 @register.tag("component_block")

tests/templates/slotted_template_with_missing_variable.html

@@ -0,0 +1,7 @@
+{% load component_tags %}
+<custom-template>
+    {{ missing_context_variable }}
+    <header>{% slot header %}Default header{% endslot %}</header>
+    <main>{% slot main %}Default main{% endslot %}</main>
+    <footer>{% slot footer %}Default footer{% endslot %}</footer>
+</custom-template>

tests/templates/template_with_provided_and_default_parameters.html

@@ -0,0 +1,2 @@
+Provided variable: <strong>{{ variable }}</strong>
+Default: <p>{{ default_param }}</p>

tests/test_templatetags.py

@@ -33,6 +33,11 @@ class SlottedComponent(component.Component):
         return "slotted_template.html"
 
 
+class SlottedComponentWithMissingVariable(component.Component):
+    def template(self, context):
+        return "slotted_template_with_missing_variable.html"
+
+
 class SlottedComponentNoSlots(component.Component):
     def template(self, context):
         return "slotted_template_no_slots.html"
@@ -46,6 +51,14 @@ class SlottedComponentWithContext(component.Component):
         return "slotted_template.html"
 
 
+class ComponentWithProvidedAndDefaultParameters(component.Component):
+    def context(self, variable, default_param="default text"):
+        return {"variable": variable, 'default_param': default_param}
+
+    def template(self, context):
+        return "template_with_provided_and_default_parameters.html"
+
+
 class ComponentTemplateTagTest(SimpleTestCase):
     def setUp(self):
         # NOTE: component.registry is global, so need to clear before each test
@@ -255,7 +268,7 @@ class ComponentSlottedTemplateTagTest(SimpleTestCase):
 
         self.assertHTMLEqual(rendered, "<custom-template></custom-template>")
 
-    def test_slotted_template_without_slots_an_single_quotes(self):
+    def test_slotted_template_without_slots_and_single_quotes(self):
         component.registry.register(name="test", component=SlottedComponentNoSlots)
         template = Template(
             """
@@ -266,3 +279,37 @@ class ComponentSlottedTemplateTagTest(SimpleTestCase):
         rendered = template.render(Context({}))
 
         self.assertHTMLEqual(rendered, "<custom-template></custom-template>")
+
+
+class SlottedTemplateRegressionTests(SimpleTestCase):
+    def setUp(self):
+        # NOTE: component.registry is global, so need to clear before each test
+        component.registry.clear()
+
+    def test_slotted_template_that_uses_missing_variable(self):
+        component.registry.register(name="test", component=SlottedComponentWithMissingVariable)
+        template = Template(
+            """
+            {% load component_tags %}
+            {% component_block 'test' %}{% endcomponent_block %}
+        """
+        )
+        rendered = template.render(Context({}))
+
+        self.assertHTMLEqual(rendered, """
+            <custom-template>
+                <header>Default header</header>
+                <main>Default main</main>
+                <footer>Default footer</footer>
+            </custom-template>
+        """)
+
+    def test_component_block_accepts_provided_and_default_parameters(self):
+        component.registry.register(name="test", component=ComponentWithProvidedAndDefaultParameters)
+
+        template = Template(
+            '{% load component_tags %}{% component_block "test" variable="provided value" %}{% endcomponent_block %}'
+        )
+        rendered = template.render(Context({}))
+        self.assertHTMLEqual(rendered,
+                             "Provided variable: <strong>provided value</strong>\nDefault: <p>default text</p>")