renderers: honor show_label and label_class on checkbox labels

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Fix `form_check_class` being ignored for single checkboxes; it was only applied to `RadioSelect` and `CheckboxSelectMultiple` (#290).
+- Fix `show_label` and `label_class` being ignored for the label next to a checkbox. `show_label=False` and `show_label='sr-only'` now add `sr-only`, `show_label='skip'` omits the label, and `label_class` extends `form-check-label` instead of being dropped (#127).
 - Fix `size` not being applied to the input group wrapper when a field has an addon, so `input-group-sm` and `input-group-lg` were missing and the addon rendered at the wrong height (#128).
 - Add a system check that warns about keys in the `BOOTSTRAP4` setting that the package does not read, such as `base_url`, dropped in 0.0.8 (`bootstrap4.W001`, #883). Silence it with `SILENCED_SYSTEM_CHECKS` if you keep extra keys deliberately.
 - Document that `use_i18n` in `BOOTSTRAP4` is always overwritten by Django's `USE_I18N`.

src/bootstrap4/renderers.py

@@ -340,12 +340,22 @@ def list_to_class(self, html, klass):
                     pass
         return str(soup)
 
+    def get_checkbox_label_class(self):
+        """Return the class for the label that sits next to a checkbox inside the form-check div."""
+        # form-check-label is structural Bootstrap markup, so label_class extends it instead of replacing it.
+        label_class = add_css_class(self.label_class, "form-check-label", prepend=True)
+        if not self.show_label or self.show_label == "sr-only":
+            label_class = add_css_class(label_class, "sr-only")
+        return label_class
+
     def add_checkbox_label(self, html):
+        if self.show_label == "skip":
+            return html
         return html + render_label(
             content=self.field.label,
             label_for=self.field.id_for_label,
             label_title=escape(strip_tags(self.field_help)),
-            label_class="form-check-label",
+            label_class=self.get_checkbox_label_class(),
         )
 
     def fix_date_select_input(self, html):

tests/test_forms.py

@@ -326,6 +326,21 @@ def test_show_label_skip(self):
         res = render_template_with_form("{% bootstrap_form form show_label='skip' %}", {"form": form})
         self.assertNotIn("<label>", res)
 
+    def test_show_label_false_for_checkbox(self):
+        """show_label=False should hide the checkbox label, not be ignored (#127)."""
+        res = render_template_with_form("{% bootstrap_field form.cc_myself show_label=False %}")
+        self.assertIn('class="form-check-label sr-only"', res)
+
+    def test_show_label_skip_for_checkbox(self):
+        """show_label='skip' should drop the checkbox label entirely (#127)."""
+        res = render_template_with_form("{% bootstrap_field form.cc_myself show_label='skip' %}")
+        self.assertNotIn("<label", res)
+
+    def test_label_class_for_checkbox(self):
+        """label_class should extend form-check-label rather than be dropped (#127)."""
+        res = render_template_with_form("{% bootstrap_field form.cc_myself label_class='my-label' %}")
+        self.assertIn('class="form-check-label my-label"', res)
+
     def test_for_formset(self):
         TestFormSet = formset_factory(CharFieldTestForm, extra=1)
         test_formset = TestFormSet()