From cde2a9bc9367ad917f896d7ff8abfd5c04aae9b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Lov=C3=A9n?= <thomasloven@gmail.com>
Date: Thu, 14 Feb 2019 12:11:01 +0100
Subject: [PATCH] Make the element more well behaved

---
 slider-entity-row.js | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/slider-entity-row.js b/slider-entity-row.js
index 68370b2..e85c899 100644
--- a/slider-entity-row.js
+++ b/slider-entity-row.js
@@ -1,6 +1,8 @@
 class SliderEntityRow extends Polymer.Element {
 
   static get template() {
+    if(!this._hass || !this._config)
+      return Polymer.html``;
     const style = Polymer.html`
       <style>
         .flex {
@@ -157,6 +159,14 @@ class SliderEntityRow extends Polymer.Element {
     this.min = config.min || 0;
     this.max = config.max || 100;
     this.step = config.step || 5;
+
+    if(this._hass && this._config) {
+      this.stateObj = this._config.entity in hass.states ? hass.states[this._config.entity] : null;
+      if(this.stateObj) {
+        this.value = this.controller.get(this.stateObj);
+        this.displaySlider = this.controller.supported(this.stateObj);
+      }
+    }
   }
 
   statusString(stateObj) {
@@ -167,10 +177,13 @@ class SliderEntityRow extends Polymer.Element {
 
   set hass(hass) {
     this._hass = hass;
-    this.stateObj = this._config.entity in hass.states ? hass.states[this._config.entity] : null;
-    if(this.stateObj) {
-      this.value = this.controller.get(this.stateObj);
-      this.displaySlider = this.controller.supported(this.stateObj);
+
+    if(hass && this._config) {
+      this.stateObj = this._config.entity in hass.states ? hass.states[this._config.entity] : null;
+      if(this.stateObj) {
+        this.value = this.controller.get(this.stateObj);
+        this.displaySlider = this.controller.supported(this.stateObj);
+      }
     }
   }