blocks: reset block errors when subwidget is prefilled (#48453)

tests/form_pages/test_block.py

@@ -412,6 +412,7 @@ def test_block_string_prefill(pub, blocks_feature):
     resp = app.get(formdef.get_url())
     resp.form['f1'] = 'Hello'
     resp = resp.form.submit('submit')  # -> 2nd page
+    assert not resp.pyquery('#form_error_f3')  # not marked as error
     assert resp.form['f3$element0$f123'].value == 'Hello World'
     resp = resp.form.submit('submit')  # -> validation page
     resp = resp.form.submit('submit')  # -> end page

wcs/blocks.py

@@ -284,6 +284,11 @@ class BlockWidget(WidgetList):
             # database in JSON.
             self.value['schema'] = {x.id: x.key for x in self.block.fields}
 
+    def unparse(self):
+        self._parsed = False
+        for widget in self.widgets:
+            widget._parsed = False
+
     def parse(self, request=None):
         if not self._parsed:
             self._parsed = True

wcs/forms/root.py

@@ -384,15 +384,25 @@ class FormPage(Directory, FormTemplateMixin):
                     v = field.convert_value_to_str(v)
                 widget.set_value(v)
                 widget.transfer_form_value(req)
+
+                if block:
+                    # reset parent block if subwidget has changed; this
+                    # prevents "required field" to be displayed on fields that
+                    # have just been prefilled.
+                    form.get_widget('f%s' % block.id).unparse()
+                    form.get_widget('f%s' % block.id).clear_error()
+
                 if field.type == 'item' and v and widget.value != v:
                     # mark field as invalid if the value was not accepted
                     # (this is required by quixote>=3 as the value would
                     # not be evaluated in the initial GET request of the
                     # page).
                     widget.set_error(get_selection_error_text())
+
                 if locked:
                     widget.readonly = 'readonly'
                     widget.attrs['readonly'] = 'readonly'
+
                 had_prefill = True
         return had_prefill