Fix runtime import to determine new attribute types

yorm/bases/mappable.py

@@ -4,7 +4,6 @@
 import functools
 
 from .. import common
-from ..mapper import get_mapper
 
 
 log = common.logger(__name__)
@@ -22,7 +21,7 @@ def fetch_before(method):
     def wrapped(self, *args, **kwargs):
         """Decorated method."""
         if not _private_call(method, args):
-            mapper = get_mapper(self)
+            mapper = common.get_mapper(self)
             if mapper and mapper.modified:
                 log.debug("Fetching before call: %s", method.__name__)
                 mapper.fetch()
@@ -49,7 +48,7 @@ def wrapped(self, *args, **kwargs):
         result = method(self, *args, **kwargs)
 
         if not _private_call(method, args):
-            mapper = get_mapper(self)
+            mapper = common.get_mapper(self)
             if mapper and mapper.auto:
                 log.debug("Storing after call: %s", method.__name__)
                 mapper.store()

yorm/common.py

@@ -6,6 +6,7 @@
 
 # CONSTANTS ####################################################################
 
+MAPPER = '__mapper__'
 
 PRINT_VERBOSITY = 0  # minimum verbosity to using `print`
 STR_VERBOSITY = 3  # minimum verbosity to use verbose `__str__`
@@ -49,3 +50,20 @@ def __init__(self, getter):
 
     def __get__(self, instance, owner):
         return self.getter(owner)
+
+
+# FUNCTIONS ####################################################################
+
+
+def get_mapper(obj):
+    """Get the `Mapper` instance attached to an object."""
+    try:
+        return object.__getattribute__(obj, MAPPER)
+    except AttributeError:
+        return None
+
+
+def set_mapper(obj, mapper):
+    """Attach a `Mapper` instance to an object."""
+    setattr(obj, MAPPER, mapper)
+    return mapper

yorm/mapper.py

@@ -3,29 +3,12 @@
 import functools
 from pprint import pformat
 
-from . import common, diskutils, exceptions, settings
+from . import common, diskutils, exceptions, types, settings
 from .bases import Container
 
-MAPPER = '__mapper__'
-
 log = common.logger(__name__)
 
 
-def get_mapper(obj):
-    """Get `Mapper` instance attached to an object."""
-    try:
-        return object.__getattribute__(obj, MAPPER)
-    except AttributeError:
-        return None
-
-
-def set_mapper(obj, *args, **kwargs):
-    """Create and attach a `Mapper` instance to an object."""
-    mapper = Mapper(obj, *args, **kwargs)
-    setattr(obj, MAPPER, mapper)
-    return mapper
-
-
 def file_required(create=False):
     """Decorator for methods that require the file to exist.
 
@@ -199,10 +182,7 @@ def fetch(self):
                     log.warning(msg, name, data)
                     continue
                 else:
-                    # TODO: determine if runtime import is the best way to avoid
-                    # cyclic import
-                    from .types import match
-                    converter = match(name, data)
+                    converter = types.match(name, data)
                     self.attrs[name] = converter
 
             # Convert the loaded attribute
@@ -227,6 +207,19 @@ def fetch(self):
         # Set meta attributes
         self.modified = False
 
+    def _remap(self, obj, root):
+        """Restore mapping on nested attributes."""
+        if isinstance(obj, Container):
+            common.set_mapper(obj, root)
+
+            if isinstance(obj, dict):
+                for obj2 in obj.values():
+                    self._remap(obj2, root)
+            else:
+                assert isinstance(obj, list)
+                for obj2 in obj:
+                    self._remap(obj2, root)
+
     @file_required(create=True)
     @prevent_recursion
     def store(self):
@@ -283,16 +276,3 @@ def _write(self, text):
             self._fake = text
         else:
             diskutils.write(text, self.path)
-
-    def _remap(self, obj, root):
-        """Restore mapping on nested attributes."""
-        if isinstance(obj, Container):
-            setattr(obj, MAPPER, root)
-
-            if isinstance(obj, dict):
-                for obj2 in obj.values():
-                    self._remap(obj2, root)
-            else:
-                assert isinstance(obj, list)
-                for obj2 in obj:
-                    self._remap(obj2, root)

yorm/utilities.py

@@ -4,7 +4,7 @@
 
 from . import common, exceptions
 from .bases.mappable import patch_methods
-from .mapper import get_mapper, set_mapper
+from .mapper import Mapper
 
 log = common.logger(__name__)
 
@@ -45,7 +45,8 @@ def sync_object(instance, path, attrs=None, existing=None, **kwargs):
     patch_methods(instance)
 
     attrs = attrs or common.attrs[instance.__class__]
-    mapper = set_mapper(instance, path, attrs, **kwargs)
+    mapper = Mapper(instance, path, attrs, **kwargs)
+    common.set_mapper(instance, mapper)
     _check_existance(mapper, existing)
 
     if mapper.auto:
@@ -149,7 +150,7 @@ def update_object(instance, existing=True, force=True):
     log.info("Manually updating %r from file...", instance)
     _check_base(instance, mappable=True)
 
-    mapper = get_mapper(instance)
+    mapper = common.get_mapper(instance)
     _check_existance(mapper, existing)
 
     if mapper.modified or force:
@@ -167,7 +168,7 @@ def update_file(instance, existing=None, force=True):
     log.info("Manually saving %r to file...", instance)
     _check_base(instance, mappable=True)
 
-    mapper = get_mapper(instance)
+    mapper = common.get_mapper(instance)
     _check_existance(mapper, existing)
 
     if mapper.auto or force:
@@ -178,7 +179,7 @@ def update_file(instance, existing=None, force=True):
 
 def synced(obj):
     """Determine if an object is already mapped to a file."""
-    return bool(get_mapper(obj))
+    return bool(common.get_mapper(obj))
 
 
 def _check_base(obj, mappable=True):