setting up pyramid app: resources

ordr3/__init__.py

@@ -26,7 +26,7 @@ def main(global_config, **settings):
         # config.set_root_factory(root_factory)
 
         config.include(".adapters")
-        #  config.include('.resources')
+        config.include(".resources")
         config.include(".routes")
         # config.include('.security')
         # config.include('.views')

ordr3/resources/__init__.py

@@ -0,0 +1,31 @@
+""" base resource and resource root factory """
+
+from pyramid.security import Allow, Everyone
+
+from .base import BaseResource
+
+
+class Root(BaseResource):
+    """ Root resource """
+
+    __name__ = None
+    __parent__ = None
+
+    nodes = {}
+
+    def __init__(self, request):
+        self.request = request
+
+    def __acl__(self):
+        """ access controll list """
+        return [(Allow, Everyone, "view")]
+
+
+def includeme(config):
+    """
+    Initialize the resources for traversal in a Pyramid app.
+
+    Activate this setup using ``config.include('ordr3.resources')``.
+
+    """
+    config.set_root_factory(Root)

ordr3/resources/base.py

@@ -0,0 +1,47 @@
+""" Base Resource and Mixin classes, not to be used directly """
+
+import abc
+
+from sqlalchemy.inspection import inspect
+
+
+class BaseResource(abc.ABC):
+    """ Base Resource for all other resources """
+
+    __parent__ = None  # required by pyramid for location aware resources
+    __name__ = None  # required by pyramid for location aware resources
+
+    request = None  # current request object
+    model = None  # a related sqlalchemy model
+    nodes = {}  # static child nodes
+
+    def __init__(self, name, parent, sql_model_instance=None):
+        self.__name__ = name
+        self.__parent__ = parent
+        self.request = parent.request
+        self.model = sql_model_instance
+
+    @abc.abstractmethod
+    def __acl__(self):
+        """ Access controll list """
+
+    def __getitem__(self, key):
+        """ returns child resources """
+        child_node_class = self.nodes.get(key, None)
+        if child_node_class:
+            return child_node_class(key, self)
+        try:
+            return super().__getitem__(key)
+        except AttributeError:
+            raise KeyError()
+
+    @classmethod
+    def from_sqla(cls, sql_model_instance, parent):
+        """ initializes a resource from an SQLalchemy object """
+        primary_keys = inspect(sql_model_instance).identity
+        if primary_keys is None:
+            raise ValueError("Cannot init resource for primary key: None")
+        elif len(primary_keys) != 1:
+            raise ValueError("Cannot init resource for composite primary key")
+        primary_key = str(primary_keys[0])
+        return cls(primary_key, parent, sql_model_instance)

ordr3/routes.py

@@ -1,2 +1,8 @@
 def includeme(config):
+    """
+    Initialize routes in a Pyramid app.
+
+    Activate this setup using ``config.include('ordr3.routes')``.
+
+    """
     config.add_static_view("static", "static", cache_max_age=3600)