[feature] Refactor global variables initialisation and also accept co…

…nfigs from Env variables as priority.

django_dynamic_fixture/global_settings.py

@@ -4,6 +4,7 @@
 Module that contains wrappers and shortcuts.
 This is the facade of all features of DDF.
 """
+import os
 import sys
 import warnings
 
@@ -28,67 +29,60 @@ class DDFImproperlyConfigured(Exception):
     "DDF is improperly configured. Some global settings has bad value in django settings."
 
 
-def get_boolean_config(config_name, default=False):
+def get_ddf_config(name, default, cast=None, options=None, msg=''):
     try:
-        if hasattr(settings, config_name) and getattr(settings, config_name) not in [True, False]:
-            # to educate users to use this property correctly.
+        value = os.getenv(name) # Priority for Env variables
+        if not value:
+            value = getattr(settings, name) if hasattr(settings, name) else default
+        value = cast(value) if cast else value
+        if options and value not in options:
+            # to educate users to use the property correctly.
             raise DDFImproperlyConfigured()
-        return getattr(settings, config_name) if hasattr(settings, config_name) else default
-    except DDFImproperlyConfigured:
-        six.reraise(DDFImproperlyConfigured, DDFImproperlyConfigured("%s (%s) must be True or False." % (config_name, getattr(settings, config_name))), sys.exc_info()[2])
+        return value
+    except Exception as e:
+        six.reraise(
+            DDFImproperlyConfigured,
+            DDFImproperlyConfigured('{}="{}": {} ({})'.format(name, value, msg, e),
+            sys.exc_info()[2])
+        )
 
 
-# DDF_DEFAULT_DATA_FIXTURE default = 'sequential'
-# It must be 'sequential', 'static_sequential', 'global_sequential', 'random' or 'path.to.CustomDataFixtureClass'
-try:
-    INTERNAL_DATA_FIXTURES = {'sequential': SequentialDataFixture(),
-                              'static_sequential': StaticSequentialDataFixture(),
-                              'global_sequential': GlobalSequentialDataFixture(),
-                              'random': RandomDataFixture()}
-    if hasattr(settings, 'DDF_DEFAULT_DATA_FIXTURE'):
-        if settings.DDF_DEFAULT_DATA_FIXTURE in INTERNAL_DATA_FIXTURES.keys():
-            DDF_DEFAULT_DATA_FIXTURE = INTERNAL_DATA_FIXTURES[settings.DDF_DEFAULT_DATA_FIXTURE]
-        else:
-            # path.to.CustomDataFixtureClass
-            mod_name, obj_name = get_mod_func(settings.DDF_DEFAULT_DATA_FIXTURE)
-            module = import_module(mod_name)
-            custom_data_fixture = getattr(module, obj_name)
-            DDF_DEFAULT_DATA_FIXTURE = custom_data_fixture()
-    else:
-        DDF_DEFAULT_DATA_FIXTURE = INTERNAL_DATA_FIXTURES['sequential']
-except:
-    six.reraise(DDFImproperlyConfigured, DDFImproperlyConfigured("DDF_DEFAULT_DATA_FIXTURE (%s) must be 'sequential', 'static_sequential', 'global_sequential', 'random' or 'path.to.CustomDataFixtureClass'." % settings.DDF_DEFAULT_DATA_FIXTURE), sys.exc_info()[2])
+def get_boolean_config(config_name, default=False):
+    return get_ddf_config(config_name, default, options=[True, False], msg='it must be True or False')
 
 
-# DDF_IGNORE_FIELDS default = []
-try:
-    DDF_IGNORE_FIELDS = list(settings.DDF_IGNORE_FIELDS) if hasattr(settings, 'DDF_IGNORE_FIELDS') else []
-except Exception as e:
-    six.reraise(DDFImproperlyConfigured, DDFImproperlyConfigured("DDF_IGNORE_FIELDS (%s) must be a list of strings" % settings.DDF_IGNORE_FIELDS), sys.exc_info()[2])
+def get_data_fixture(default='sequential'):
+    # It must be 'sequential', 'static_sequential', 'global_sequential', 'random' or 'path.to.CustomDataFixtureClass'
+    try:
+        INTERNAL_DATA_FIXTURES = {'sequential': SequentialDataFixture(),
+                                  'static_sequential': StaticSequentialDataFixture(),
+                                  'global_sequential': GlobalSequentialDataFixture(),
+                                  'random': RandomDataFixture()}
+        if hasattr(settings, 'DDF_DEFAULT_DATA_FIXTURE'):
+            if settings.DDF_DEFAULT_DATA_FIXTURE in INTERNAL_DATA_FIXTURES.keys():
+                return INTERNAL_DATA_FIXTURES[settings.DDF_DEFAULT_DATA_FIXTURE]
+            else:
+                # path.to.CustomDataFixtureClass
+                mod_name, obj_name = get_mod_func(settings.DDF_DEFAULT_DATA_FIXTURE)
+                module = import_module(mod_name)
+                custom_data_fixture = getattr(module, obj_name)
+                return custom_data_fixture()
+        else:
+            return INTERNAL_DATA_FIXTURES[default]
+    except:
+        six.reraise(DDFImproperlyConfigured, DDFImproperlyConfigured("DDF_DEFAULT_DATA_FIXTURE (%s) must be 'sequential', 'static_sequential', 'global_sequential', 'random' or 'path.to.CustomDataFixtureClass'." % settings.DDF_DEFAULT_DATA_FIXTURE), sys.exc_info()[2])
 
 
-# DDF_FK_MIN_DEPTH default = 0
-try:
-    DDF_FK_MIN_DEPTH = int(settings.DDF_FK_MIN_DEPTH) if hasattr(settings, 'DDF_FK_MIN_DEPTH') else 0
-except Exception as e:
-    six.reraise(DDFImproperlyConfigured, DDFImproperlyConfigured("DDF_FK_MIN_DEPTH (%s) must be a integer number." % settings.DDF_FK_MIN_DEPTH), sys.exc_info()[2])
-
+DDF_DEFAULT_DATA_FIXTURE = get_data_fixture(default='sequential')
+DDF_IGNORE_FIELDS = get_ddf_config('DDF_IGNORE_FIELDS', default=[], cast=list, msg='it must be a list of strings')
+DDF_FK_MIN_DEPTH = get_ddf_config('DDF_FK_MIN_DEPTH', default=0, cast=int, msg='it must be a integer number')
 if hasattr(settings, 'DDF_NUMBER_OF_LAPS'):
     warnings.warn(
         "The old DDF_NUMBER_OF_LAPS settings was replaced by the new DDF_FK_MIN_DEPTH.",
         DeprecationWarning
     )
-
-# DDF_FIELD_FIXTURES default = {}
-try:
-    DDF_FIELD_FIXTURES = dict(settings.DDF_FIELD_FIXTURES) if hasattr(settings, 'DDF_FIELD_FIXTURES') else {}
-    DDF_DEFAULT_DATA_FIXTURE.plugins = DDF_FIELD_FIXTURES
-except Exception as e:
-    six.reraise(DDFImproperlyConfigured, DDFImproperlyConfigured("DDF_FIELD_FIXTURES (%s) must be a dict." % settings.DDF_FIELD_FIXTURES), sys.exc_info()[2])
-
-
-
+DDF_FIELD_FIXTURES = get_ddf_config('DDF_FIELD_FIXTURES', default={}, cast=dict, msg='it must be a dict')
+DDF_DEFAULT_DATA_FIXTURE.plugins = DDF_FIELD_FIXTURES
 DDF_FILL_NULLABLE_FIELDS = get_boolean_config('DDF_FILL_NULLABLE_FIELDS', default=False)
 DDF_VALIDATE_MODELS = get_boolean_config('DDF_VALIDATE_MODELS', default=False)
 DDF_DEBUG_MODE = get_boolean_config('DDF_DEBUG_MODE', default=False)
-