Introduced op decorators to map Thing op to methods

Author: Joel Collins

src/labthings/td.py

@@ -23,8 +23,9 @@ def view_to_thing_action_forms(rules: list, view: View, external: bool = True):
     """
     forms = []
 
-    # HTTP invokeaction requires POST method
-    if hasattr(view, "post"):
+    # Get map from invokeaction to HTTP method
+    meth = getattr(view, "_opmap", {}).get("invokeaction", "post")
+    if hasattr(view, meth):
         prop_urls = [rule_to_path(rule) for rule in rules]
 
         # Get input content_type
@@ -36,7 +37,7 @@ def view_to_thing_action_forms(rules: list, view: View, external: bool = True):
         for url in prop_urls:
             form = {
                 "op": "invokeaction",
-                "htv:methodName": "POST",
+                "htv:methodName": meth.upper(),
                 "href": ResourceURL(url, external=external),
                 "contentType": content_type,
             }
@@ -70,38 +71,17 @@ def view_to_thing_property_forms(rules: list, view: View, external: bool = True)
     # Get input content_type
     content_type = getattr(view, "content_type", "application/json")
 
-    # HTTP readproperty requires GET method
-    if hasattr(view, "get"):
-        for url in prop_urls:
-            form = {
-                "op": "readproperty",
-                "htv:methodName": "GET",
-                "href": ResourceURL(url, external=external),
-                "contentType": content_type,
-            }
-            forms.append(form)
-
-    # HTTP writeproperty requires PUT method
-    if hasattr(view, "put"):
-        for url in prop_urls:
-            form = {
-                "op": "writeproperty",
-                "htv:methodName": "PUT",
-                "href": ResourceURL(url, external=external),
-                "contentType": content_type,
-            }
-            forms.append(form)
-
-    # HTTP writeproperty may use POST method
-    elif hasattr(view, "post"):
-        for url in prop_urls:
-            form = {
-                "op": "writeproperty",
-                "htv:methodName": "POST",
-                "href": ResourceURL(url, external=external),
-                "contentType": content_type,
-            }
-            forms.append(form)
+    # Get map from ops to HTTP methods
+    for op, meth in getattr(view, "_opmap", {}).items():
+        if hasattr(view, meth):
+            for url in prop_urls:
+                form = {
+                    "op": op,
+                    "htv:methodName": meth.upper(),
+                    "href": ResourceURL(url, external=external),
+                    "contentType": content_type,
+                }
+                forms.append(form)
 
     return forms
 

src/labthings/views/__init__.py

@@ -6,6 +6,8 @@
 from .args import use_args
 from .marshalling import marshal_with
 
+from . import op
+
 from ..utilities import unpack, get_docstring, get_summary, merge
 from ..representations import DEFAULT_REPRESENTATIONS
 from ..find import current_labthing
@@ -18,7 +20,7 @@
 
 import logging
 
-__all__ = ["MethodView", "View", "ActionView", "PropertyView"]
+__all__ = ["MethodView", "View", "ActionView", "PropertyView", "op"]
 
 
 class View(MethodView):
@@ -37,6 +39,7 @@ class View(MethodView):
 
     # Internal
     _cls_tags = set()  # Class tags that shouldn't be removed
+    _opmap = {}  # Mapping of Thing Description ops to class methods
 
     def __init__(self, *args, **kwargs):
         MethodView.__init__(self, *args, **kwargs)
@@ -165,10 +168,17 @@ class ActionView(View):
     default_stop_timeout: int = None  # Time in seconds to wait for the action thread to end after a stop request before terminating it forcefully
 
     # Internal
+    _opmap = {
+        "invokeaction": "post"
+    }  # Mapping of Thing Description ops to class methods
     _cls_tags = {"actions"}
     _deque = Deque()  # Action queue
     _emergency_pool = Pool()
 
+    def __init__(self, *args, **kwargs):
+
+        super().__init__(*args, **kwargs)
+
     @classmethod
     def get(cls):
         """
@@ -320,6 +330,10 @@ class PropertyView(View):
     responses = {}  # Custom responses for all interactions
 
     # Internal
+    _opmap = {
+        "readproperty": "get",
+        "writeproperty": "put",
+    }  # Mapping of Thing Description ops to class methods
     _cls_tags = {"properties"}
 
     @classmethod

src/labthings/views/op.py

@@ -0,0 +1,40 @@
+import copy
+
+
+class readproperty:
+    def __init__(self, fn):
+        self.fn = fn
+
+    def __set_name__(self, owner, name):
+        if hasattr(owner, "_opmap"):
+            owner._opmap = copy.copy(owner._opmap)
+            owner._opmap.update({"readproperty": name})
+
+        # then replace ourself with the original method
+        setattr(owner, name, self.fn)
+
+
+class writeproperty:
+    def __init__(self, fn):
+        self.fn = fn
+
+    def __set_name__(self, owner, name):
+        if hasattr(owner, "_opmap"):
+            owner._opmap = copy.copy(owner._opmap)
+            owner._opmap.update({"writeproperty": name})
+
+        # then replace ourself with the original method
+        setattr(owner, name, self.fn)
+
+
+class observeproperty:
+    def __init__(self, fn):
+        self.fn = fn
+
+    def __set_name__(self, owner, name):
+        if hasattr(owner, "_opmap"):
+            owner._opmap = copy.copy(owner._opmap)
+            owner._opmap.update({"observeproperty": name})
+
+        # then replace ourself with the original method
+        setattr(owner, name, self.fn)

tests/test_semantics.py

@@ -1,6 +1,6 @@
 import pytest
 
-from labthings.views import View
+from labthings.views import View, op
 from labthings import semantics
 
 
@@ -12,6 +12,7 @@ def thing_description(thing):
 def test_moz_BooleanProperty(helpers, app, thing_description, app_ctx, schemas_path):
     @semantics.moz.BooleanProperty()
     class Index(View):
+        @op.readproperty
         def get(self):
             return "GET"
 
@@ -32,6 +33,7 @@ def get(self):
 def test_moz_LevelProperty(helpers, app, thing_description, app_ctx, schemas_path):
     @semantics.moz.LevelProperty(0, 100)
     class Index(View):
+        @op.readproperty
         def get(self):
             return "GET"
 
@@ -55,6 +57,7 @@ def get(self):
 def test_moz_BrightnessProperty(helpers, app, thing_description, app_ctx, schemas_path):
     @semantics.moz.BrightnessProperty()
     class Index(View):
+        @op.readproperty
         def get(self):
             return "GET"
 
@@ -78,6 +81,7 @@ def get(self):
 def test_moz_OnOffProperty(helpers, app, thing_description, app_ctx, schemas_path):
     @semantics.moz.OnOffProperty()
     class Index(View):
+        @op.readproperty
         def get(self):
             return "GET"
 

tests/test_td.py

@@ -2,7 +2,7 @@
 
 from labthings import fields
 
-from labthings.views import View, PropertyView, ActionView
+from labthings.views import View, PropertyView, ActionView, op
 
 
 @pytest.fixture
@@ -170,6 +170,7 @@ def test_td_property_post_to_write(
     helpers, app, thing_description, app_ctx, schemas_path
 ):
     class Index(PropertyView):
+        @op.writeproperty
         def post(self):
             return "POST"
 
@@ -197,12 +198,9 @@ def post(self):
 def test_td_property_different_content_type(
     helpers, app, thing_description, app_ctx, schemas_path
 ):
-    class Index(ActionView):
+    class Index(PropertyView):
         content_type = "text/plain; charset=us-ascii"
 
-        def get(self):
-            return "GET"
-
         def put(self):
             return "PUT"
 
@@ -226,7 +224,7 @@ class Index(ActionView):
         response_content_type = "text/plain; charset=us-ascii"
 
         def post(self):
-            return "PUT"
+            return "POST"
 
     app.add_url_rule("/", view_func=Index.as_view("index"))
     rules = app.url_map._rules_by_endpoint["index"]