Start portlets get implementation

src/plone/restapi/services/configure.zcml

@@ -18,6 +18,7 @@
   <include package=".navigation"/>
   <include package=".history"/>
   <include package=".locking" />
+  <include package=".portlets"/>
   <include package=".principals"/>
   <include package=".registry"/>
   <include package=".roles"/>

src/plone/restapi/services/portlets/configure.zcml

@@ -0,0 +1,15 @@
+<configure
+    xmlns="http://namespaces.zope.org/zope"
+    xmlns:plone="http://namespaces.plone.org/plone">
+
+  <adapter factory=".get.Portlets" name="portlets"/>
+
+  <plone:service
+    method="GET"
+    for="zope.interface.Interface"
+    factory=".get.PortletsGet"
+    name="@portlets"
+    permission="zope2.View"
+    />
+
+</configure>

src/plone/restapi/services/portlets/get.py

@@ -0,0 +1,75 @@
+# -*- coding: utf-8 -*-
+from plone.app.portlets.interfaces import IPortletTypeInterface
+from plone.portlets.interfaces import IPortletAssignmentMapping
+from plone.portlets.interfaces import IPortletAssignmentSettings
+from plone.portlets.interfaces import IPortletManager
+from plone.restapi.interfaces import IExpandableElement
+from plone.restapi.services import Service
+from zope.component import adapter
+from zope.component import getUtilitiesFor
+from zope.component import queryMultiAdapter
+from zope.component.hooks import getSite
+from zope.interface import implementer
+from zope.interface import Interface
+from zope.interface import providedBy
+
+
+@implementer(IExpandableElement)
+@adapter(Interface, Interface)
+class Portlets(object):
+
+    def __init__(self, context, request):
+        self.context = context
+        self.request = request
+        self.portal = getSite()
+
+    def __call__(self, expand=False):
+        result = {
+            'navigation': {
+                '@id': '{}/@navigation'.format(self.context.absolute_url()),
+            },
+        }
+        if not expand:
+            return result
+
+        portlets_schemata = {
+            iface: name
+            for name, iface in getUtilitiesFor(IPortletTypeInterface)
+        }
+        items = {}
+        for manager_name, manager in getUtilitiesFor(IPortletManager):
+            mapping = queryMultiAdapter((self.context, manager),
+                                        IPortletAssignmentMapping)
+            if mapping is None:
+                continue
+            mapping = mapping.__of__(self.context)
+            for name, assignment in mapping.items():
+                type_ = None
+                schema = None
+                for schema in providedBy(assignment).flattened():
+                    type_ = portlets_schemata.get(schema, None)
+                    if type_ is not None:
+                        break
+                if type_ is None:
+                    continue
+                assignment = assignment.__of__(mapping)
+                settings = IPortletAssignmentSettings(assignment)
+                if manager_name not in items:
+                    items[manager_name] = []
+                items[manager_name].append({
+                    'type': type_,
+                    'visible': settings.get('visible', True),
+                    'assignment': {
+                        name: getattr(assignment, name, None)
+                        for name in schema.names()
+                    },
+                })
+        result['portlets']['items'] = items
+        return result
+
+
+class PortletsGet(Service):
+
+    def reply(self):
+        portlets = Portlets(self.context, self.request)
+        return portlets(expand=True)['portlets']