json cell: prioritise varnames in context (#17904)

combo/data/models.py

@@ -854,7 +854,7 @@ class JsonCellBase(CellBase):
         extra_context = super(JsonCellBase, self).get_cell_extra_context(context)
         if self.varnames and context.get('request'):
             for varname in self.varnames:
-                if varname in context['request'].GET and varname not in context:
+                if varname in context['request'].GET:
                     context[varname] = context['request'].GET[varname]
         self._json_content = None
 
@@ -1069,8 +1069,11 @@ class ConfigJsonCell(JsonCellBase):
         return config_form_class
 
     def get_cell_extra_context(self, context, **kwargs):
-        context.update(copy.copy(self.parameters)) # early push for templated URLs
-        ctx = super(ConfigJsonCell, self).get_cell_extra_context(context, **kwargs)
+        # create a new context with parameters, for templated URLs
+        ctx = copy.copy(context)
         ctx['parameters'] = self.parameters
-        ctx.update(self.parameters)
+        ctx.update(copy.copy(self.parameters))
+        # add varnames, get requests results
+        extra = super(ConfigJsonCell, self).get_cell_extra_context(ctx, **kwargs)
+        ctx.update(extra)
         return ctx

tests/test_cells.py

@@ -333,6 +333,20 @@ def test_config_json_cell_with_varnames(app):
             assert '/var1=foo/' in resp.body
             assert '/var2=bar/' in resp.body
 
+            resp = app.get(url + '?var2=plop')  # use var1 default value
+            assert requests_get.call_count == 1  # no request, var1 is missing
+            assert '/var1=/' in resp.body
+            assert '/var2=plop/' in resp.body
+
+            cell.parameters = {'var1': 'defaultvalue1'}
+            cell.save()
+            resp = app.get(url + '?var2=plop')  # use var1 default value
+            assert requests_get.call_count == 2
+            assert requests_get.call_args[0][0] == 'http://foo?varone=defaultvalue1&vartwo=plop'
+            assert '/var1=defaultvalue1/' in resp.body
+            assert '/var2=plop/' in resp.body
+
+
 def test_config_json_cell_with_param_in_url(app):
     page = Page(title='example page', slug='index')
     page.save()