Add helpers to all selectors (#12230)

src/components/entity/ha-entities-picker.ts

@@ -16,6 +16,8 @@ class HaEntitiesPickerLight extends LitElement {
 
   @property({ type: Boolean }) public required?: boolean;
 
+  @property() public helper?: string;
+
   /**
    * Show entities from specific domains.
    * @type {string}
@@ -110,6 +112,7 @@ class HaEntitiesPickerLight extends LitElement {
           .includeUnitOfMeasurement=${this.includeUnitOfMeasurement}
           .entityFilter=${this._entityFilter}
           .label=${this.pickEntityLabel}
+          .helper=${this.helper}
           .required=${this.required && !currentEntities.length}
           @value-changed=${this._addEntity}
         ></ha-entity-picker>

src/components/entity/ha-entity-attribute-picker.ts

@@ -28,6 +28,8 @@ class HaEntityAttributePicker extends LitElement {
 
   @property() public value?: string;
 
+  @property() public helper?: string;
+
   @property({ type: Boolean }) private _opened = false;
 
   @query("ha-combo-box", true) private _comboBox!: HaComboBox;
@@ -64,6 +66,7 @@ class HaEntityAttributePicker extends LitElement {
         )}
         .disabled=${this.disabled || !this.entityId}
         .required=${this.required}
+        .helper=${this.helper}
         .allowCustomValue=${this.allowCustomValue}
         item-value-path="value"
         item-label-path="label"

src/components/entity/ha-entity-picker.ts

@@ -48,6 +48,8 @@ export class HaEntityPicker extends LitElement {
 
   @property() public value?: string;
 
+  @property() public helper?: string;
+
   /**
    * Show entities from specific domains.
    * @type {Array}
@@ -304,6 +306,7 @@ export class HaEntityPicker extends LitElement {
         .label=${this.label === undefined
           ? this.hass.localize("ui.components.entity.entity-picker.entity")
           : this.label}
+        .helper=${this.helper}
         .allowCustomValue=${this.allowCustomEntity}
         .filteredItems=${this._states}
         .renderer=${rowRenderer}