Better error handling. Fix #132

Author: thomasloven

slider-entity-row.js

@@ -29,6 +29,8 @@ class SliderEntityRow extends LitElement {
 
   setConfig(config) {
     this._config = config;
+    if(!config.entity)
+      throw new Error(`No entity specified.`);
     const domain = config.entity.split('.')[0];
     const ctrlClass = controllers[domain];
     if(!ctrlClass)
@@ -52,6 +54,15 @@ class SliderEntityRow extends LitElement {
   render() {
     const c = this.ctrl;
     c.hass = this.hass;
+    if (!c.stateObj)
+      return html`
+      <hui-warning>
+        ${this.hass.localize("ui.panel.lovelace.warning.entity_not_found",
+          "entity",
+          this._config.entity
+        )}
+      </hui-warning>
+      `
     const dir = this.hass.translationMetadata.translations[this.hass.language || "en"].isRTL ? "rtl" : "ltr";
     const slider = html`
       <ha-slider

src/main.js

@@ -3,7 +3,7 @@ default_config:
 demo:
 
 lovelace:
-  mode: yaml
+  mode: storage
   resources:
     - url: /local/slider-entity-row.js
       type: module

test/configuration.yaml

@@ -41,7 +41,28 @@ x-command: &x-command |
       \"version\": 3
     }
     " > /config/.storage/onboarding &&
-  hass -c /config'
+  echo "
+    {
+      \"data\": {
+        \"items\": [
+          {
+            \"id\": \"1\",
+            \"type\": \"module\",
+            \"url\": \"/local/slider-entity-row.js\"
+          },
+          {
+            \"id\": \"2\",
+            \"type\": \"module\",
+            \"url\": \"/local/card-mod.js\"
+          }
+        ]
+      },
+      \"key\": \"lovelace_resources\",
+      \"version\": 1
+    }
+    " > /config/.storage/lovelace_resources &&
+
+  hass -v -c /config'
 
 version: '3.5'
 services:

test/docker-compose.yml

@@ -5,6 +5,7 @@ views:
   - !include views/2_options.yaml
   - !include views/3_attributes.yaml
   - !include views/4_width.yaml
+  - !include views/5_errors.yaml
   - title: test
     cards:
       - type: picture-elements

test/lovelace.yaml

@@ -0,0 +1,22 @@
+x-anchors:
+  desc: &desc
+    type: markdown
+    style: |
+      code {
+        font-size: 8pt;
+        line-height: normal;
+        white-space: pre-wrap;
+        }
+
+title: Errors
+cards:
+  - type: entities
+    entities:
+      - type: section
+        label: No entity
+      - type: custom:slider-entity-row
+
+      - type: section
+        label: Unknown entity
+      - type: custom:slider-entity-row
+        entity: light.no_light