blocks: add support for post conditions (#71778)

tests/form_pages/test_block.py

@@ -2881,3 +2881,108 @@ def test_block_multiple_rows_single_draft(pub, logged_user, tracking_code):
 
     assert formdef.data_class().count() == 1
     assert formdef.data_class().select()[0].status == 'wf-new'
+
+
+def test_block_field_post_condition(pub):
+    FormDef.wipe()
+    BlockDef.wipe()
+
+    block = BlockDef()
+    block.name = 'foobar'
+    block.fields = [
+        fields.StringField(id='123', label='Foo', varname='foo'),
+        fields.StringField(id='234', label='Bar', varname='bar'),
+    ]
+    block.post_conditions = [
+        {
+            'condition': {'type': 'django', 'value': 'block_var_foo|startswith:"b"'},
+            'error_message': 'foo must start with a b.',
+        },
+        {
+            'condition': {'type': 'django', 'value': 'block_var_foo == block_var_bar'},
+            'error_message': 'foo and bar must be identical.',
+        },
+    ]
+
+    block.store()
+
+    formdef = FormDef()
+    formdef.name = 'form title'
+    formdef.fields = [
+        fields.BlockField(id='1', label='test', block_slug='foobar'),
+    ]
+    formdef.store()
+
+    app = get_app(pub)
+    resp = app.get(formdef.get_url())
+    resp.form['f1$element0$f123'] = 'foo'
+    resp.form['f1$element0$f234'] = 'bar'
+    resp = resp.form.submit('submit')  # -> error
+    assert (
+        resp.pyquery('.widget-with-error .error').text()
+        == 'foo must start with a b. foo and bar must be identical.'
+    )
+
+    resp.form['f1$element0$f123'] = 'baz'
+    resp.form['f1$element0$f234'] = 'bar'
+    resp = resp.form.submit('submit')  # -> error
+    assert resp.pyquery('.widget-with-error .error').text() == 'foo and bar must be identical.'
+
+    resp.form['f1$element0$f123'] = 'baz'
+    resp.form['f1$element0$f234'] = 'baz'
+    resp = resp.form.submit('submit')  # -> validation page
+
+    assert resp.form['f1$element0$f123'].attrs['readonly']
+    resp = resp.form.submit('submit')  # -> end page
+
+    formdata = formdef.data_class().select()[0]
+    assert formdata.status == 'wf-new'
+    assert formdata.data == {
+        '1': {'data': [{'123': 'baz', '234': 'baz'}], 'schema': {'123': 'string', '234': 'string'}},
+        '1_display': 'foobar',
+    }
+
+    # multiple rows
+    formdef.fields[0].max_items = 3
+    formdef.store()
+    formdef.data_class().wipe()
+    resp = app.get(formdef.get_url())
+    resp.form['f1$element0$f123'] = 'baz'
+    resp.form['f1$element0$f234'] = 'bar'
+    resp = resp.form.submit('f1$add_element')
+    assert not resp.pyquery('.widget-with-error')
+
+    resp.form['f1$element1$f123'] = 'bar'
+    resp.form['f1$element1$f234'] = 'bar'
+    resp = resp.form.submit('submit')  # -> error
+    assert (
+        resp.pyquery('.widget-with-error[data-block-row="element0"] .error').text()
+        == 'foo and bar must be identical.'
+    )
+    assert resp.pyquery('.widget-with-error[data-block-row="element1"] .error').text() == ''
+
+    resp.form['f1$element1$f234'] = 'baz'
+    resp = resp.form.submit('submit')  # -> error
+    assert (
+        resp.pyquery('.widget-with-error[data-block-row="element0"] .error').text()
+        == 'foo and bar must be identical.'
+    )
+    assert (
+        resp.pyquery('.widget-with-error[data-block-row="element1"] .error').text()
+        == 'foo and bar must be identical.'
+    )
+
+    resp.form['f1$element0$f123'] = 'bar'
+    resp.form['f1$element1$f234'] = 'bar'
+    resp = resp.form.submit('submit')  # -> validation page
+    assert resp.form['f1$element0$f123'].attrs['readonly']
+    resp = resp.form.submit('submit')  # -> end page
+    formdata = formdef.data_class().select()[0]
+    assert formdata.status == 'wf-new'
+    assert formdata.data == {
+        '1': {
+            'data': [{'123': 'bar', '234': 'bar'}, {'123': 'bar', '234': 'bar'}],
+            'schema': {'123': 'string', '234': 'string'},
+        },
+        '1_display': 'foobar, foobar',
+    }

wcs/blocks.py

@@ -24,7 +24,7 @@ from contextlib import contextmanager
 from quixote import get_publisher, get_request, get_response
 from quixote.html import htmltag, htmltext
 
-from . import data_sources, fields
+from . import conditions, data_sources, fields
 from .categories import BlockCategory
 from .formdata import FormData
 from .qommon import _, misc
@@ -455,6 +455,22 @@ class BlockSubWidget(CompositeWidget):
                 all_lists = False
             if widget_value.get(widget.field.id) not in empty_values:
                 empty = False
+
+        if not empty and self.block.post_conditions:
+            error_messages = []
+            with self.block.visibility_context(value, self.index):
+                for i, post_condition in enumerate(self.block.post_conditions):
+                    condition = post_condition.get('condition')
+                    try:
+                        if conditions.Condition(condition, record_errors=False).evaluate():
+                            continue
+                    except RuntimeError:
+                        pass
+                    error_message = post_condition.get('error_message')
+                    error_messages.append(get_publisher().translate(error_message))
+            if error_messages:
+                self.set_error(' '.join(error_messages))
+
         if empty and not all_lists and not get_publisher().keep_all_block_rows_mode:
             value = None
             for widget in self.get_widgets():  # reset "required" errors
@@ -559,6 +575,10 @@ class BlockWidget(WidgetList):
             self._parse(request)
             if self.required and self.value is None:
                 self.set_error(_(self.REQUIRED_ERROR))
+            for widget in self.widgets:
+                # mark required rows with a special attribute, to avoid doubling the
+                # error messages in the template.
+                widget.is_required_error = bool(widget.error == self.REQUIRED_ERROR)
         return self.value
 
     def add_media(self):

wcs/qommon/templates/qommon/forms/widgets/block_sub.html

@@ -6,6 +6,7 @@
 {% endblock %}
 
 {% block widget-content %}
+  {% if not widget.readonly and widget.error and not widget.is_required_error %}<div class="error"><p>{{ widget.error }}</p></div>{% endif %}
   {% for subwidget in widget.get_widgets %}
     {% if widget.readonly and not subwidget.field.include_in_validation_page %}<div style="display: none">{% endif %}
     {{ subwidget.render|safe }}