Let esphomeyaml know about class inheritance (#229)

* Allow overriding setup priority

* Add inheritance tree

* Global variables

* Tests and better validation

* Fix

* Lint

esphomeyaml/components/globals.py

@@ -0,0 +1,35 @@
+import voluptuous as vol
+
+from esphomeyaml import config_validation as cv
+from esphomeyaml.const import CONF_ID, CONF_INITIAL_VALUE, CONF_RESTORE_VALUE, CONF_TYPE
+from esphomeyaml.helpers import App, Component, Pvariable, RawExpression, TemplateArguments, add, \
+    esphomelib_ns, setup_component
+
+GlobalVariableComponent = esphomelib_ns.class_('GlobalVariableComponent', Component)
+
+GLOBAL_VAR_SCHEMA = vol.Schema({
+    vol.Required(CONF_ID): cv.declare_variable_id(GlobalVariableComponent),
+    vol.Required(CONF_TYPE): cv.string_strict,
+    vol.Optional(CONF_INITIAL_VALUE): cv.string_strict,
+    vol.Optional(CONF_RESTORE_VALUE): cv.boolean,
+}).extend(cv.COMPONENT_SCHEMA.schema)
+
+CONFIG_SCHEMA = vol.All(cv.ensure_list, [GLOBAL_VAR_SCHEMA])
+
+
+def to_code(config):
+    for conf in config:
+        type_ = RawExpression(conf[CONF_TYPE])
+        template_args = TemplateArguments(type_)
+        res_type = GlobalVariableComponent.template(template_args)
+        initial_value = None
+        if CONF_INITIAL_VALUE in conf:
+            initial_value = RawExpression(conf[CONF_INITIAL_VALUE])
+        rhs = App.Pmake_global_variable(template_args, initial_value)
+        glob = Pvariable(conf[CONF_ID], rhs, type=res_type)
+
+        if conf.get(CONF_RESTORE_VALUE, False):
+            hash_ = hash(conf[CONF_ID].id) % 2**32
+            add(glob.set_restore_value(hash_))
+
+        setup_component(glob, conf)