Support loading capabilites YAML into Python classes.

src/escpos/capabilities.py

@@ -0,0 +1,83 @@
+import re
+from os import path
+import yaml
+
+
+with open(path.join(path.dirname(__file__), 'capabilities.yml')) as f:
+    PROFILES = yaml.load(f)
+
+
+class Profile(object):
+
+    profile_data = {}
+
+    def __init__(self, columns=None):
+        self.default_columns = columns
+
+    def __getattr__(self, name):
+        return self.profile_data[name]
+
+    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]
+
+
+def get_profile(name=None, **kwargs):
+    if isinstance(name, Profile):
+        return name
+
+    clazz = get_profile_class(name or 'default')
+    return clazz(**kwargs)
+
+
+
+CLASS_CACHE = {}
+
+
+def get_profile_class(name):
+    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})
+        CLASS_CACHE[name] = new_class
+
+    return CLASS_CACHE[name]
+
+
+def clean(s):
+   # Remove invalid characters
+   s = re.sub('[^0-9a-zA-Z_]', '', s)
+   # Remove leading characters until we find a letter or underscore
+   s = re.sub('^[^a-zA-Z_]+', '', s)
+   return str(s)
+
+
+def resolve_profile_data(name):
+    data = PROFILES[name]
+    inherits = data.get('inherits')
+    if not inherits:
+        return data
+
+    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
+
+