add YAML config parser

cement/ext/ext_yaml.py

@@ -1,9 +1,11 @@
 """YAML Framework Extension"""
 
+import os
 import sys
 import yaml
 from ..core import backend, output, hook, handler
 from ..utils.misc import minimal_logger
+import cement.ext.ext_configparser
 
 LOG = minimal_logger(__name__)
 
@@ -78,8 +80,27 @@ def set_output_handler(app):
         app._setup_output_handler()
 
 
+class YamlConfigHandler(cement.ext.ext_configobj.ConfigObjConfigHandler):
+    class Meta:
+        interface = cement.core.config.IConfig
+        label = 'yaml'
+
+    def parse_file(self, file_path):
+        file_path = os.path.abspath(os.path.expanduser(file_path))
+        if os.path.exists(file_path):
+            LOG.debug("config file '%s' exists, loading settings..." %
+                    file_path)
+            self.merge(dict(yaml.load(open(file_path))))
+            return True
+        else:
+            LOG.debug("config file '%s' does not exist, skipping..." %
+                      file_path)
+            return False
+
+
 def load():
     """Called by the framework when the extension is 'loaded'."""
     handler.register(YamlOutputHandler)
+    handler.register(YamlConfigHandler)
     hook.register('post_setup', add_yaml_option)
     hook.register('pre_run', set_output_handler)

tests/ext/yaml_tests.py

@@ -1,9 +1,13 @@
 """Tests for cement2.ext.ext_yaml."""
 
+import os
+import sys
 import yaml
+from tempfile import mkstemp
 from cement.core import handler, hook
 from cement.utils import test
 
+
 class YamlExtTestCase(test.CementTestCase):
     def setUp(self):
         self.app = self.make_app('tests',
@@ -18,3 +22,64 @@ class YamlExtTestCase(test.CementTestCase):
         res = self.app.render(dict(foo='bar'))
         yaml_res = yaml.dump(dict(foo='bar'))
         self.eq(res, yaml_res)
+
+
+class YamlConfigHandlerTestCase(test.CementTestCase):
+    CONFIG = '''
+    section:
+        subsection:
+            list:
+                - item1
+                - item2
+                - item3
+                - item4
+            key: value
+        key1: ok1
+        key2: ok2
+    '''
+    CONFIG_PARSED = dict(
+        section=dict(
+            subsection=dict(
+                list=['item1', 'item2', 'item3', 'item4'],
+                key='value'),
+            key1='ok1',
+            key2='ok2'))
+
+    def setUp(self):
+        _, self.tmppath = mkstemp()
+        f = open(self.tmppath, 'w+')
+        f.write(self.CONFIG)
+        f.close()
+        self.app = self.make_app('myapp',
+            extensions=['yaml'],
+            config_handler='yaml',
+            config_files = [self.tmppath],
+            argv=[]
+            )
+
+    def tearDown(self):
+        if os.path.exists(self.tmppath):
+            os.remove(self.tmppath)
+
+    def test_configobj(self):
+        self.app.setup()
+
+    def test_has_section(self):
+        self.app.setup()
+        self.ok(self.app.config.has_section('section'))
+
+    def test_keys(self):
+        self.app.setup()
+        res = 'subsection' in self.app.config.keys('section')
+        self.ok(res)
+
+    def test_parse_file_bad_path(self):
+        self.app._meta.config_files = ['./some_bogus_path']
+        self.app.setup()
+
+    def test_parse_file(self):
+        self.app.setup()
+        self.eq(self.app.config.get('section', 'key1'), 'ok1')
+
+        self.eq(self.app.config.get_section_dict('section'),
+                self.CONFIG_PARSED['section'])