Add global variables from integration configuration. Thanks, Dwains.

README.md

@@ -252,6 +252,34 @@ elements:
 
 # FAQ
 
+### How can I do global variables?
+You can add variables to the `lovelace_gen` configuration in `configuration.yaml` and then refernce them in lovelace using `{{ _global }}`.
+
+E.g.:
+```yaml
+lovelace_gen:
+  rooms:
+    - living_room
+    - kitchen
+    - bed_room
+```
+
+```yaml
+type: entities
+entities:
+  {% for room in _global.rooms %}
+  - type: custom:auto-entities
+    card:
+      type: custom:fold-entity-row
+      head:
+        type: section
+        label: {{ room|capitalize }}
+    filter:
+      include:
+        - area: {{ room }}
+  {% endfor %}
+```
+
 ### Can I use this for my general Home Assistant configuration?
 It's called **lovelace**\_gen for a reason...
 That being said - it *might* work. Or it might not. There's really no way to

custom_components/lovelace_gen/__init__.py

@@ -14,6 +14,8 @@ _LOGGER = logging.getLogger(__name__)
 
 jinja = jinja2.Environment(loader=jinja2.FileSystemLoader("/"))
 
+llgen_config = {}
+
 def load_yaml(fname, args={}):
     try:
         ll_gen = False
@@ -22,7 +24,7 @@ def load_yaml(fname, args={}):
                 ll_gen = True
 
         if ll_gen:
-            stream = io.StringIO(jinja.get_template(fname).render(args))
+            stream = io.StringIO(jinja.get_template(fname).render({**args, "_global": llgen_config}))
             stream.name = fname
             return loader.yaml.load(stream, Loader=loader.SafeLineLoader) or OrderedDict()
         else:
@@ -60,5 +62,6 @@ loader.load_yaml = load_yaml
 loader.yaml.SafeLoader.add_constructor("!include", _include_yaml)
 loader.yaml.SafeLoader.add_constructor("!file", _uncache_file)
 
-async def async_setup(*_):
+async def async_setup(hass, config):
+    llgen_config.update(config.get("lovelace_gen"));
     return True