json cell: add possibility to retrieve data from multiple URLs (#17185)

ex:
  "metro": {
    "url": "https://.../stops?identifier=[identifier]",
    "additional-data": [
       {"key": "schedule",
        "url": "https://.../schedule?stop_identifier=[identifier]"
       }
    ]
  }

combo/data/models.py

@@ -832,6 +832,14 @@ class JsonCellBase(CellBase):
     varnames = None
     force_async = False
     actions = {}
+    additional_data = None
+        # [
+        #  {'key': ...,
+        #   'url': ...,
+        #   'cache_duration': ... (optional)
+        #  },
+        #  ...
+        # ]
 
     _json_content = None
 
@@ -848,28 +856,45 @@ class JsonCellBase(CellBase):
                 if varname in context['request'].GET and varname not in context:
                     context[varname] = context['request'].GET[varname]
         self._json_content = None
-        extra_context['json'] = None
-        try:
-            url = utils.get_templated_url(self.url, context)
-        except utils.UnknownTemplateVariableError:
-            logger = logging.getLogger(__name__)
-            logger.warning('unknown variable in template URL (%s)', self.url)
-            return extra_context
-        json_response = utils.requests.get(url,
-                headers={'Accept': 'application/json'},
-                remote_service='auto',
-                cache_duration=self.cache_duration,
-                without_user=True,
-                raise_if_not_cached=not(context.get('synchronous')),
-                invalidate_cache=invalidate_cache,
-                )
-        if json_response.status_code == 200:
+
+        data_urls = [{'key': 'json', 'url': self.url, 'cache_duration': self.cache_duration}]
+        data_urls.extend(self.additional_data or [])
+
+        for data_url_dict in data_urls:
+            extra_context[data_url_dict['key']] = None
+
+        for data_url_dict in data_urls:
+            data_key = data_url_dict['key']
             try:
-                self._json_content = json.loads(json_response.content)
-            except ValueError:
+                url = utils.get_templated_url(data_url_dict['url'], context)
+            except utils.UnknownTemplateVariableError:
                 logger = logging.getLogger(__name__)
-                logger.error('invalid json content (%s)', url)
-        extra_context['json'] = self._json_content
+                logger.warning('unknown variable in template URL (%s)', self.url)
+                continue
+            json_response = utils.requests.get(url,
+                    headers={'Accept': 'application/json'},
+                    remote_service='auto',
+                    cache_duration=data_url_dict.get('cache_duration', self.cache_duration),
+                    without_user=True,
+                    raise_if_not_cached=not(context.get('synchronous')),
+                    invalidate_cache=invalidate_cache,
+                    )
+            if json_response.status_code == 200:
+                try:
+                    extra_context[data_key] = json.loads(json_response.content)
+                except ValueError:
+                    logger = logging.getLogger(__name__)
+                    logger.error('invalid json content (%s)', url)
+                    continue
+
+            # update context with data key so it can be used in future
+            # templated URLs
+            context[data_key] = extra_context[data_key]
+
+        # keep cache of first response as it may be used to find the
+        # appropriate template.
+        self._json_content = extra_context['json']
+
         return extra_context
 
     @property
@@ -1007,6 +1032,10 @@ class ConfigJsonCell(JsonCellBase):
         return settings.JSON_CELL_TYPES[self.key].get('actions',
                 JsonCellBase.actions)
 
+    @property
+    def additional_data(self):
+        return settings.JSON_CELL_TYPES[self.key].get('additional-data')
+
     @property
     def template_name(self):
         return 'combo/json/%s.html' % self.key

tests/test_cells.py

@@ -364,3 +364,45 @@ def test_json_force_async():
         assert cell.render(Context({'synchronous': True})) == 'world2'
         # rerun with stuff in cache
         assert cell.render(Context({})) == 'world2'
+
+def test_config_json_cell_additional_url(app):
+    page = Page(title='example page', slug='index')
+    page.save()
+
+    with override_settings(JSON_CELL_TYPES={
+            'test-config-json-cell-2': {
+                'name': 'Foobar',
+                'url': 'http://foo',
+                'additional-data': [
+                    {'key': 'plop', 'url': 'http://bar'},
+                ]
+            }},
+            TEMPLATE_DIRS=['%s/templates-1' % os.path.abspath(os.path.dirname(__file__))]):
+        cell = ConfigJsonCell()
+        cell.key = 'test-config-json-cell-2'
+        cell.page = page
+        cell.title = 'Example Site'
+        cell.order = 0
+        cell.save()
+
+        with mock.patch('combo.utils.requests.get') as requests_get:
+            data = {'data': 'toto'}
+            requests_get.return_value = mock.Mock(content=json.dumps(data), status_code=200)
+            url = reverse('combo-public-ajax-page-cell',
+                kwargs={'page_pk': page.id, 'cell_reference': cell.get_reference()})
+            resp = app.get(url)
+            assert resp.body.strip() == '/var1=toto/var2=toto/'
+            assert len(requests_get.mock_calls) == 2
+            assert requests_get.mock_calls[0][1][0] == 'http://foo'
+            assert requests_get.mock_calls[1][1][0] == 'http://bar'
+
+        with mock.patch('combo.utils.requests.get') as requests_get:
+            data = {'data': 'toto'}
+            requests_get.return_value = mock.Mock(content=json.dumps(data), status_code=404)
+            url = reverse('combo-public-ajax-page-cell',
+                kwargs={'page_pk': page.id, 'cell_reference': cell.get_reference()})
+            resp = app.get(url)
+            assert resp.body.strip() == '/var1=/var2=/'
+            assert len(requests_get.mock_calls) == 2
+            assert requests_get.mock_calls[0][1][0] == 'http://foo'
+            assert requests_get.mock_calls[1][1][0] == 'http://bar'