Match the current printer-db format.

src/escpos/capabilities.py

@@ -1,40 +1,53 @@
 import re
+import six
 from os import path
 import yaml
 
 
-with open(path.join(path.dirname(__file__), 'capabilities.yml')) as f:
-    PROFILES = yaml.load(f)
+# Load external printer database
+with open(path.join(path.dirname(__file__), 'capabilities.json')) as f:
+    CAPABILITIES = yaml.load(f)
+PROFILES = CAPABILITIES['profiles']
+ENCODINGS = CAPABILITIES['encodings']
 
 
-class Profile(object):
+class NotSupported(Exception):
+    pass
+
+
+class BaseProfile(object):
+    """This respresents a printer profile.
+
+    A printer profile knows about the number of columns, supported
+    features, colors and more.
+    """
 
     profile_data = {}
 
-    def __init__(self, columns=None):
-        self.default_columns = columns
-
     def __getattr__(self, name):
         return self.profile_data[name]
 
+    def get_font(self, font):
+        """Return the escpos index for `font`. Makes sure that
+        the requested `font` is valid.
+        """
+        font = {'a': 0, 'b': 1}.get(font, font)
+        if not six.text_type(font) in self.fonts:
+            raise NotSupported(
+                '"%s" is not a valid font in the current profile' % font)
+        return font
+
     def get_columns(self, font):
         """ Return the number of columns for the given font.
         """
-        if self.default_columns:
-            return self.default_columns
-
-        if 'columnConfigs' in self.profile_data:
-            columns_def = self.columnConfigs[self.defaultColumnConfig]
-
-        elif 'columns' in self.profile_data:
-            columns_def = self.columns
-
-        if isinstance(columns_def, int):
-            return columns_def
-        return columns_def[font]
+        font = self.get_font(font)
+        return self.fonts[six.text_type(font)]['columns']
 
 
 def get_profile(name=None, **kwargs):
+    """Get the profile by name; if no name is given, return the
+    default profile.
+    """
     if isinstance(name, Profile):
         return name
 
@@ -42,15 +55,19 @@ def get_profile(name=None, **kwargs):
     return clazz(**kwargs)
 
 
-
 CLASS_CACHE = {}
 
 
 def get_profile_class(name):
+    """For the given profile name, load the data from the external
+    database, then generate dynamically a class.
+    """
     if not name in CLASS_CACHE:
-        profile_data = resolve_profile_data(name)
-        class_name = '%sProfile' % clean(name)
-        new_class = type(class_name, (Profile,), {'profile_data': profile_data})
+        profile_data = PROFILES[name]
+        profile_name = clean(name)
+        class_name = '{}{}Profile'.format(
+            profile_name[0].upper(), profile_name[1:])
+        new_class = type(class_name, (BaseProfile,), {'profile_data': profile_data})
         CLASS_CACHE[name] = new_class
 
     return CLASS_CACHE[name]
@@ -64,20 +81,20 @@ def clean(s):
    return str(s)
 
 
-def resolve_profile_data(name):
-    data = PROFILES[name]
-    inherits = data.get('inherits')
-    if not inherits:
-        return data
+# For users, who want to provide their profile
+class Profile(get_profile_class('default')):
+
+    def __init__(self, columns=None):
+        super(Profile, self).__init()
+
+        self.columns = columns
+
+    def get_columns(self, font):
+        if self.columns is not None:
+            return columns
+
+        return super(Profile, self).get_columns(font)
 
-    if not isinstance(inherits, (tuple, list)):
-        inherits = [inherits]
 
-    merged = {}
-    for base in reversed(inherits):
-        base_data = resolve_profile_data(base)
-        merged.update(base_data)
-    merged.update(data)
-    return merged