Small changes to the property factories + new property for strings.

 - improve docstrings
 - use the same 'deleter' for all properties
 - new property factory: string_field
 - int_field properties return 0 if the item is not found

debexpo/plugins/api.py

@@ -85,48 +85,76 @@ def test_result(cls):
     cls.test_result = True
     return cls
 
+
 #
 # Property factories for PluginResult subclasses
 #
-
 # FIXME: move this somewhere else
 # FIXME: some of that could be abstracted
+#
 
+def _fdel(name):
+    """
+    Returns a function for deleting the dictionary's item with the
+    given key. For use in properties below.
+    """
+    def fdel(instance):
+        del instance[name]
+    return fdel
 
 def bool_field(name):
-    """ Property exposing a string ('true' or 'false') as a bool. """
+    """
+    Property exposing an item ('true' or 'false') from the plugin
+    result's dictionary as a bool.
+
+    If the dictionary does not have the requested item yet, the getter
+    will return False.
+    """
     def fget(instance):
         return True if instance.get(name, 'false') == 'true' else False
 
     def fset(instance, value):
         if not isinstance(value, bool):
             raise ValueError('Expected bool')
-        instance[name] = 'true' if value else 'false'
-
-    def fdel(instance):
-        del instance[name]
+        instance[name] = u'true' if value else u'false'
 
-    return property(fget, fset, fdel,
+    return property(fget, fset, _fdel(name),
                     "Read-write property exposing a string ('true' or 'false')"
                     " as a bool.")
 
 
 def int_field(name):
-    """ Property exposing a string as an int """
+    """
+    Property exposing a numeric item from the plugin result's dictionary as
+    an int.
+
+    If the dictionary does not have the requested item yet, the getter
+    will return 0.
+    """
     def fget(instance):
-        return int(instance[name])
+        # FIXME: better error handling
+        return int(instance.get(name, 0))
 
     def fset(instance, value):
         if not isinstance(value, int):
             raise ValueError('Expected int')
         instance[name] = unicode(value)
 
-    def fdel(instance):
-        del instance[name]
-
-    return property(fget, fset, fdel,
+    return property(fget, fset, _fdel(name),
                     'Read-write property exposing a string as an int')
 
+def string_field(name):
+    """
+    Property for accessing a string item from the plugin result's dictionary.
+    """
+    def fget(instance):
+        return instance.get(name, "")
+
+    def fset(instance, value):
+        instance[name] = value
+
+    return property(fget, fset, _fdel(name))
+
 
 #
 # Bases classes for plugins