Add fromjson filter

README.md

@@ -150,6 +150,18 @@ name: {{ name }}
 
 Be careful about the syntax here. Note that the arguments are given as a list and is indented under the `!include` statement. The second item in the list is a dictionary.
 
+> Note: If you want to pass a dictionary of values into a file, you need to convert it to json first:
+> ```yaml
+> {% set mydict = {"a": 1, "b": 2} %}
+> variable: {{ mydict | tojson }}
+> ```
+> And then convert it back from json inside the file:
+> ```yaml
+> content: The value of a is {{ (variable | fromjson)['a'] }}
+> ```
+>
+> The `fromjson` filter is a feature of `lovelace_gen` and not normally included in jinja.
+
 ## Invalidate cache of files
 
 If you use lots of custom lovelace cards, chances are that you have run into caching problems at one point or another.

custom_components/lovelace_gen/__init__.py

@@ -12,8 +12,13 @@ from homeassistant.exceptions import HomeAssistantError
 
 _LOGGER = logging.getLogger(__name__)
 
+def fromjson(value):
+    return json.loads(value)
+
 jinja = jinja2.Environment(loader=jinja2.FileSystemLoader("/"))
 
+jinja.filters['fromjson'] = fromjson
+
 llgen_config = {}
 
 def load_yaml(fname, args={}):
@@ -89,4 +94,4 @@ def compose_node(self, parent, index):
     self.ascend_resolver()
     return node
 
-yaml.composer.Composer.compose_node = compose_node
+yaml.composer.Composer.compose_node = compose_node