Handle different request and response types in TD

Author: Joel Collins

src/labthings/td.py

@@ -44,15 +44,16 @@ def view_to_thing_action_forms(rules: list, view: View):
                 break
 
         for url in prop_urls:
-            forms.append(
-                {
-                    "op": ["invokeaction"],
-                    "htv:methodName": "POST",
-                    "href": url,
-                    "contentType": content_type,
-                    "response": {"contentType": response_content_type},
-                }
-            )
+            form = {
+                "op": ["invokeaction"],
+                "htv:methodName": "POST",
+                "href": url,
+                "contentType": content_type,
+            }
+            if response_content_type != content_type:
+                form["responses"] = {"contentType": response_content_type}
+
+            forms.append(form)
 
     return forms
 
@@ -84,43 +85,49 @@ def view_to_thing_property_forms(rules: list, view: View):
             response_content_type = responses[response_code].get("content_type")
             break
 
+    # TODO: Clean up repeated code
+
     # HTTP readproperty requires GET method
     if hasattr(view, "get"):
         for url in prop_urls:
-            forms.append(
-                {
-                    "op": ["readproperty"],
-                    "htv:methodName": "GET",
-                    "href": url,
-                    "contentType": content_type,
-                    "response": {"contentType": response_content_type},
-                }
-            )
+            form = {
+                "op": ["readproperty"],
+                "htv:methodName": "GET",
+                "href": url,
+                "contentType": content_type,
+                "response": {"contentType": response_content_type},
+            }
+            if response_content_type != content_type:
+                form["responses"] = {"contentType": response_content_type}
+            forms.append(form)
 
     # HTTP writeproperty requires PUT method
     if hasattr(view, "put"):
         for url in prop_urls:
-            forms.append(
-                {
-                    "op": ["writeproperty"],
-                    "htv:methodName": "PUT",
-                    "href": url,
-                    "contentType": content_type,
-                    "response": {"contentType": response_content_type},
-                }
-            )
+            form = {
+                "op": ["writeproperty"],
+                "htv:methodName": "PUT",
+                "href": url,
+                "contentType": content_type,
+                "response": {"contentType": response_content_type},
+            }
+            if response_content_type != content_type:
+                form["responses"] = {"contentType": response_content_type}
+            forms.append(form)
+
     # HTTP writeproperty may use POST method
     elif hasattr(view, "post"):
         for url in prop_urls:
-            forms.append(
-                {
-                    "op": ["writeproperty"],
-                    "htv:methodName": "POST",
-                    "href": url,
-                    "contentType": content_type,
-                    "response": {"contentType": response_content_type},
-                }
-            )
+            form = {
+                "op": ["writeproperty"],
+                "htv:methodName": "POST",
+                "href": url,
+                "contentType": content_type,
+                "response": {"contentType": response_content_type},
+            }
+            if response_content_type != content_type:
+                form["responses"] = {"contentType": response_content_type}
+            forms.append(form)
 
     return forms
 

tests/old_api/test_server_spec_td.py

@@ -87,7 +87,6 @@ def test_td_action_with_schema(
                     "htv:methodName": "POST",
                     "href": "/",
                     "contentType": "application/json",
-                    "response": {"contentType": "application/json"},
                 }
             ],
             "input": {

tests/test_td.py

@@ -87,7 +87,6 @@ def test_td_action_with_schema(
                     "htv:methodName": "POST",
                     "href": "/",
                     "contentType": "application/json",
-                    "response": {"contentType": "application/json"},
                 }
             ],
             "input": {
@@ -191,3 +190,28 @@ def post(self):
             == "POST"
         )
         helpers.validate_thing_description(thing_description, app_ctx, schemas_path)
+
+
+def test_td_property_different_response_type(
+    helpers, app, thing_description, app_ctx, schemas_path
+):
+    class Index(View):
+        def get(self):
+            return "GET"
+
+        def put(self):
+            return "PUT"
+
+    Index.schema = fields.Int()
+    Index.responses[200] = {"content_type": "text/plain; charset=us-ascii"}
+
+    app.add_url_rule("/", view_func=Index.as_view("index"))
+    rules = app.url_map._rules_by_endpoint["index"]
+
+    thing_description.property(rules, Index)
+
+    with app_ctx.test_request_context():
+        assert "index" in thing_description.to_dict()["properties"]
+        for form in thing_description.to_dict()["properties"]["index"]["forms"]:
+            assert form["response"]["contentType"] == "text/plain; charset=us-ascii"
+        helpers.validate_thing_description(thing_description, app_ctx, schemas_path)