diff --git a/homeassistant/util/template.py b/homeassistant/util/template.py index 37eed7ad3f5cdfbd105e36a61547abb596894787..107532db776062fca9e4f338957680c4bdc5d80b 100644 --- a/homeassistant/util/template.py +++ b/homeassistant/util/template.py @@ -5,9 +5,24 @@ homeassistant.util.template Template utility methods for rendering strings with HA data. """ # pylint: disable=too-few-public-methods +import json from jinja2.sandbox import ImmutableSandboxedEnvironment +def render_with_possible_json_value(hass, template, value): + """ Renders template with value exposed. + If valid JSON will expose value_json too. """ + variables = { + 'value': value + } + try: + variables['value_json'] = json.loads(value) + except ValueError: + pass + + return render(hass, template, variables) + + def render(hass, template, variables=None, **kwargs): """ Render given template. """ if variables is not None: diff --git a/tests/util/test_template.py b/tests/util/test_template.py index e85ed6dbba6cfe4ba78b4da2f05953e17d72290f..5c1dfff1f85acdc925f0808baaee7fd3f8e9ba18 100644 --- a/tests/util/test_template.py +++ b/tests/util/test_template.py @@ -72,3 +72,15 @@ class TestUtilTemplate(unittest.TestCase): def test_passing_vars_as_vars(self): self.assertEqual( '127', template.render(self.hass, '{{ hello }}', {'hello': 127})) + + def test_render_with_possible_json_value_with_valid_json(self): + self.assertEqual( + 'world', + template.render_with_possible_json_value( + self.hass, '{{ value_json.hello }}', '{"hello": "world"}')) + + def test_render_with_possible_json_value_with_invalid_json(self): + self.assertEqual( + '', + template.render_with_possible_json_value( + self.hass, '{{ value_json }}', '{ I AM NOT JSON }'))