forms: fix loss of value of map widget in multipage forms (#8222)

tests/test_form_pages.py

@@ -1126,3 +1126,29 @@ def test_form_map_field_back_and_submit(pub):
     data_id = formdef.data_class().select()[0].id
     data = formdef.data_class().get(data_id)
     assert data.data == {'1': None, '0': '1.234;-1.234'}
+
+def test_form_map_multi_page(pub):
+    formdef = create_formdef()
+    formdef.fields = [fields.PageField(id='0', label='1st page', type='page'),
+            fields.MapField(id='1', label='map'),
+            fields.PageField(id='2', label='2nd page', type='page'),
+            fields.StringField(id='3', label='string 2')]
+    formdef.store()
+    resp = get_app(pub).get('/test/')
+    formdef.data_class().wipe()
+    resp.forms[0]['f1$latlng'] = '1.234;-1.234'
+    assert resp.forms[0].fields['submit'][0].value_if_submitted() == 'Next'
+    resp = resp.forms[0].submit('submit')
+    assert resp.forms[0]['previous']
+    resp.forms[0]['f3'] = 'bar'
+    resp = resp.forms[0].submit('submit')
+    assert resp.forms[0]['f1$latlng'].value == '1.234;-1.234'
+    assert 'Check values then click submit.' in resp.body
+    resp = resp.forms[0].submit('submit')
+    assert resp.status_int == 302
+    resp = resp.follow()
+    assert 'The form has been recorded' in resp.body
+    assert formdef.data_class().count() == 1
+    data_id = formdef.data_class().select()[0].id
+    data = formdef.data_class().get(data_id)
+    assert data.data == {'1': '1.234;-1.234', '3': 'bar'}

wcs/qommon/form.py

@@ -1985,7 +1985,10 @@ $(function() {
 class MapWidget(CompositeWidget):
     def __init__(self, name, value=None, **kwargs):
         CompositeWidget.__init__(self, name, value, **kwargs)
-        self.add(HiddenWidget, 'latlng')
+        self.add(HiddenWidget, 'latlng', value=value)
+        widget = self.get_widget('latlng')
+        if value and not get_request().form.get(widget.name):
+            get_request().form[widget.name] = value
         self.readonly = kwargs.pop('readonly', False)
         self.kwargs = kwargs