Merge pull request #265 from sjhewitt/next-sql-composite

next: handle sqlalchemy composite columns

graphene-sqlalchemy/graphene_sqlalchemy/converter.py

@@ -37,6 +37,33 @@ def convert_sqlalchemy_relationship(relationship, registry):
     return Dynamic(dynamic_type)
 
 
+def convert_sqlalchemy_composite(composite, registry):
+    converter = registry.get_converter_for_composite(composite.composite_class)
+    if not converter:
+        try:
+            raise Exception(
+                "Don't know how to convert the composite field %s (%s)" %
+                (composite, composite.composite_class))
+        except AttributeError:
+            # handle fields that are not attached to a class yet (don't have a parent)
+            raise Exception(
+                "Don't know how to convert the composite field %r (%s)" %
+                (composite, composite.composite_class))
+    return converter(composite, registry)
+
+
+def _register_composite_class(cls, registry=None):
+    if registry is None:
+        from .registry import get_global_registry
+        registry = get_global_registry()
+
+    def inner(fn):
+        registry.register_composite_converter(cls, fn)
+    return inner
+
+convert_sqlalchemy_composite.register = _register_composite_class
+
+
 def convert_sqlalchemy_column(column, registry=None):
     return convert_sqlalchemy_type(getattr(column, 'type', None), column, registry)
 

graphene-sqlalchemy/graphene_sqlalchemy/registry.py

@@ -2,6 +2,7 @@ class Registry(object):
     def __init__(self):
         self._registry = {}
         self._registry_models = {}
+        self._registry_composites = {}
 
     def register(self, cls):
         from .types import SQLAlchemyObjectType
@@ -16,6 +17,12 @@ class Registry(object):
     def get_type_for_model(self, model):
         return self._registry.get(model)
 
+    def register_composite_converter(self, composite, converter):
+        self._registry_composites[composite] = converter
+
+    def get_converter_for_composite(self, composite):
+        return self._registry_composites.get(composite)
+
 
 registry = None
 

graphene-sqlalchemy/graphene_sqlalchemy/tests/test_converter.py

@@ -1,5 +1,6 @@
 from py.test import raises
 from sqlalchemy import Column, Table, types
+from sqlalchemy.orm import composite
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy_utils import ChoiceType, ScalarListType
 from sqlalchemy.dialects import postgresql
@@ -8,6 +9,7 @@ import graphene
 from graphene.relay import Node
 from graphene.types.json import JSONString
 from ..converter import (convert_sqlalchemy_column,
+                         convert_sqlalchemy_composite,
                          convert_sqlalchemy_relationship)
 from ..fields import SQLAlchemyConnectionField
 from ..types import SQLAlchemyObjectType
@@ -25,6 +27,19 @@ def assert_column_conversion(sqlalchemy_type, graphene_field, **kwargs):
     return field
 
 
+def assert_composite_conversion(composite_class, composite_columns, graphene_field,
+                                registry, **kwargs):
+    composite_column = composite(composite_class, *composite_columns,
+                                 doc='Custom Help Text', **kwargs)
+    graphene_type = convert_sqlalchemy_composite(composite_column, registry)
+    assert isinstance(graphene_type, graphene_field)
+    field = graphene_type.Field()
+    # SQLAlchemy currently does not persist the doc onto the column, even though
+    # the documentation says it does....
+    # assert field.description == 'Custom Help Text'
+    return field
+
+
 def test_should_unknown_sqlalchemy_field_raise_exception():
     with raises(Exception) as excinfo:
         convert_sqlalchemy_column(None)
@@ -210,3 +225,42 @@ def test_should_postgresql_jsonb_convert():
 
 def test_should_postgresql_hstore_convert():
     assert_column_conversion(postgresql.HSTORE(), JSONString)
+
+
+def test_should_composite_convert():
+
+    class CompositeClass(object):
+        def __init__(self, col1, col2):
+            self.col1 = col1
+            self.col2 = col2
+
+    registry = Registry()
+
+    @convert_sqlalchemy_composite.register(CompositeClass, registry)
+    def convert_composite_class(composite, registry):
+        return graphene.String(description=composite.doc)
+
+    assert_composite_conversion(CompositeClass,
+                                (Column(types.Unicode(50)),
+                                 Column(types.Unicode(50))),
+                                graphene.String,
+                                registry)
+
+
+def test_should_unknown_sqlalchemy_composite_raise_exception():
+    registry = Registry()
+
+    with raises(Exception) as excinfo:
+
+        class CompositeClass(object):
+            def __init__(self, col1, col2):
+                self.col1 = col1
+                self.col2 = col2
+
+        assert_composite_conversion(CompositeClass,
+                                    (Column(types.Unicode(50)),
+                                     Column(types.Unicode(50))),
+                                    graphene.String,
+                                    registry)
+
+    assert 'Don\'t know how to convert the composite field' in str(excinfo.value)

graphene-sqlalchemy/graphene_sqlalchemy/types.py

@@ -6,6 +6,7 @@ from sqlalchemy.orm.exc import NoResultFound
 from graphene import ObjectType, Field
 from graphene.relay import is_node
 from .converter import (convert_sqlalchemy_column,
+                        convert_sqlalchemy_composite,
                         convert_sqlalchemy_relationship)
 from .utils import is_mapped
 
@@ -35,6 +36,17 @@ def construct_fields(options):
         converted_column = convert_sqlalchemy_column(column, options.registry)
         fields[name] = converted_column
 
+    for name, composite in inspected_model.composites.items():
+        is_not_in_only = only_fields and name not in only_fields
+        is_already_created = name in options.fields
+        is_excluded = name in exclude_fields or is_already_created
+        if is_not_in_only or is_excluded:
+            # We skip this field if we specify only_fields and is not
+            # in there. Or when we excldue this field in exclude_fields
+            continue
+        converted_composite = convert_sqlalchemy_composite(composite, options.registry)
+        fields[name] = converted_composite
+
     # Get all the columns for the relationships on the model
     for relationship in inspected_model.relationships:
         is_not_in_only = only_fields and relationship.key not in only_fields