Add handling of DynamicObject

capnp/capnp.pyx

@@ -9,7 +9,7 @@
 cimport cython
 cimport capnp_cpp as capnp
 cimport schema_cpp
-from capnp_cpp cimport Schema as C_Schema, StructSchema as C_StructSchema, DynamicStruct as C_DynamicStruct, DynamicValue as C_DynamicValue, Type as C_Type, DynamicList as C_DynamicList, fixMaybe, getEnumString, SchemaParser as C_SchemaParser, ParsedSchema as C_ParsedSchema, VOID, ArrayPtr, StringPtr, String, StringTree, DynamicOrphan as C_DynamicOrphan, WordArrayPtr
+from capnp_cpp cimport Schema as C_Schema, StructSchema as C_StructSchema, DynamicStruct as C_DynamicStruct, DynamicValue as C_DynamicValue, Type as C_Type, DynamicList as C_DynamicList, fixMaybe, getEnumString, SchemaParser as C_SchemaParser, ParsedSchema as C_ParsedSchema, VOID, ArrayPtr, StringPtr, String, StringTree, DynamicOrphan as C_DynamicOrphan, DynamicObject as C_DynamicObject, WordArrayPtr
 
 from schema_cpp cimport Node as C_Node, EnumNode as C_EnumNode
 from cython.operator cimport dereference as deref
@@ -352,7 +352,7 @@ cdef to_python_reader(C_DynamicValue.Reader self, object parent):
     elif type == capnp.TYPE_VOID:
         return None
     elif type == capnp.TYPE_OBJECT:
-        raise ValueError("Cannot convert type to Python. Object type is not supported in pycapnp yet")
+        return _DynamicObjectReader()._init(self.asObject(), parent)
     elif type == capnp.TYPE_UNKNOWN:
         raise ValueError("Cannot convert type to Python. Type is unknown by capnproto library")
     else:
@@ -382,7 +382,7 @@ cdef to_python_builder(C_DynamicValue.Builder self, object parent):
     elif type == capnp.TYPE_VOID:
         return None
     elif type == capnp.TYPE_OBJECT:
-        raise ValueError("Cannot convert type to Python. Object type is not supported in pycapnp yet")
+        raise ValueError("Cannot convert type to Python. Type is 'Object', but is being used improperly. You can only get 'Object' types from a struct")
     elif type == capnp.TYPE_UNKNOWN:
         raise ValueError("Cannot convert type to Python. Type is unknown by capnproto library")
     else:
@@ -618,7 +618,21 @@ cdef class _DynamicStructBuilder:
         return ret
 
     cdef _get(self, field):
-        return to_python_builder(self.thisptr.get(field), self._parent)
+        cdef C_DynamicValue.Builder value = self.thisptr.get(field)
+
+        if value.getType() == capnp.TYPE_OBJECT:
+            return _DynamicObjectBuilder(field, self)
+        else:
+            return to_python_builder(value, self._parent)
+
+    cpdef _get_object(self, field, schema):
+        cdef _StructSchema s
+        if hasattr(schema, 'schema'):
+            s = schema.schema
+        else:
+            s = schema
+
+        return _DynamicStructBuilder()._init(self.thisptr.getObject(field, s.thisptr), self._parent)
 
     def __getattr__(self, field):
         return self._get(field)
@@ -771,6 +785,32 @@ cdef class _DynamicOrphan:
     def __repr__(self):
         return repr(self.get())
 
+cdef class _DynamicObjectReader:
+    cdef C_DynamicObject.Reader thisptr
+    cdef public object _parent
+    cdef _init(self, C_DynamicObject.Reader other, object parent):
+        self.thisptr = other
+        self._parent = parent
+        return self
+
+    cpdef as_struct(self, schema):
+        cdef _StructSchema s
+        if hasattr(schema, 'schema'):
+            s = schema.schema
+        else:
+            s = schema
+
+        return _DynamicStructReader()._init(self.thisptr.as(s.thisptr), self._parent)
+
+cdef class _DynamicObjectBuilder:
+    cdef public object _field, _parent_struct
+    def __init__(self, field, parent_struct):
+        self._field = field
+        self._parent_struct = parent_struct
+
+    cpdef as_struct(self, schema):
+        return self._parent_struct._get_object(self._field, schema)
+
 cdef class _Schema:
     cdef C_Schema thisptr
     cdef _init(self, C_Schema other):

capnp/capnp_cpp.pxd

@@ -138,6 +138,7 @@ cdef extern from "capnp/dynamic.h" namespace " ::capnp":
             void adopt(char *, DynamicOrphan) except +ValueError
             DynamicOrphan disown(char *)
             DynamicStruct.Reader asReader()
+            DynamicStruct.Builder getObject(char *, StructSchema)
 
 cdef extern from "fixMaybe.h":
     EnumSchema.Enumerant fixMaybe(Maybe[EnumSchema.Enumerant]) except +ValueError
@@ -149,6 +150,13 @@ cdef extern from "capnp/dynamic.h" namespace " ::capnp":
         uint16_t getRaw()
         Maybe[EnumSchema.Enumerant] getEnumerant()
 
+    cdef cppclass DynamicObject:
+        cppclass Reader:
+            DynamicStruct.Reader as(StructSchema schema)
+        cppclass Builder:
+            DynamicObject.Reader asReader()
+            # DynamicList::Reader as(ListSchema schema) const;
+
     cdef cppclass DynamicList:
         cppclass Reader:
             DynamicValueForward.Reader operator[](uint) except +ValueError
@@ -193,6 +201,7 @@ cdef extern from "capnp/dynamic.h" namespace " ::capnp":
             char * asText"as< ::capnp::Text>().cStr"()
             DynamicList.Reader asList"as< ::capnp::DynamicList>"()
             DynamicStruct.Reader asStruct"as< ::capnp::DynamicStruct>"()
+            DynamicObject.Reader asObject"as< ::capnp::DynamicObject>"()
             DynamicEnum asEnum"as< ::capnp::DynamicEnum>"()
             Data.Reader asData"as< ::capnp::Data>"()
 

test/object.capnp

@@ -0,0 +1,21 @@
+@0x8186ddb142b58556;
+
+struct Person {
+  id @0 :UInt32;
+  name @1 :Text;
+}
+
+struct Place {
+  id @0 :UInt32;
+  name @1 :Text;
+}
+
+struct Thing {
+  id @0 :UInt64;
+  value @1 :UInt64;
+}
+
+struct TestObject {
+  object @0 :Object;
+}
+

test/test_object.py

@@ -0,0 +1,25 @@
+import pytest
+import capnp
+import os
+import math
+
+this_dir = os.path.dirname(__file__)
+
+@pytest.fixture
+def object():
+     return capnp.load(os.path.join(this_dir, 'object.capnp'))
+
+def test_object_basic(object):
+    obj = object.TestObject.new_message()
+    person = obj.object.as_struct(object.Person)
+    person.name = 'test'
+    person.id = 1000
+
+    same_person = obj.object.as_struct(object.Person)
+    assert same_person.name == 'test'
+    assert same_person.id == 1000
+
+    obj_r = obj.as_reader()
+    same_person = obj_r.object.as_struct(object.Person)
+    assert same_person.name == 'test'
+    assert same_person.id == 1000