Detect and format timestamp attributes

src/common/string/is_date.ts

@@ -0,0 +1,11 @@
+// https://regex101.com/r/kc5C14/2
+const regExpString = "^\\d{4}-(0[1-9]|1[0-2])-([12]\\d|0[1-9]|3[01])";
+
+const regExp = new RegExp(regExpString + "$");
+// 2nd expression without the "end of string" enforced, so it can be used
+// to just verify the start of a string and then based on that result e.g.
+// check for a full timestamp string efficiently.
+const regExpNoStringEnd = new RegExp(regExpString);
+
+export const isDate = (input: string, allowCharsAfterDate = false): boolean =>
+  allowCharsAfterDate ? regExpNoStringEnd.test(input) : regExp.test(input);

src/common/string/is_timestamp.ts

@@ -0,0 +1,11 @@
+// https://stackoverflow.com/a/14322189/1947205
+// Changes:
+// 1. Do not allow a plus or minus at the start.
+// 2. Enforce that we have a "T" or a blank after the date portion
+//    to ensure we have a timestamp and not only a date.
+// 3. Disallow dates based on week number.
+// 4. Disallow dates only consisting of a year.
+// https://regex101.com/r/kc5C14/3
+const regexp = /^\d{4}-(0[1-9]|1[0-2])-([12]\d|0[1-9]|3[01])[T| ](((([01]\d|2[0-3])((:?)[0-5]\d)?|24:?00)([.,]\d+(?!:))?)(\8[0-5]\d([.,]\d+)?)?([zZ]|([+-])([01]\d|2[0-3]):?([0-5]\d)?)?)$/;
+
+export const isTimestamp = (input: string): boolean => regexp.test(input);

src/components/ha-attributes.ts

@@ -1,16 +1,14 @@
 import { HassEntity } from "home-assistant-js-websocket";
 import { css, CSSResultGroup, html, LitElement, TemplateResult } from "lit";
 import { customElement, property, state } from "lit/decorators";
-import { until } from "lit/directives/until";
 import { haStyle } from "../resources/styles";
 import { HomeAssistant } from "../types";
 import hassAttributeUtil, {
   formatAttributeName,
+  formatAttributeValue,
 } from "../util/hass-attributes-util";
 import "./ha-expansion-panel";
 
-let jsYamlPromise: Promise<typeof import("js-yaml")>;
-
 @customElement("ha-attributes")
 class HaAttributes extends LitElement {
   @property({ attribute: false }) public hass!: HomeAssistant;
@@ -124,38 +122,7 @@ class HaAttributes extends LitElement {
       return "-";
     }
     const value = this.stateObj.attributes[attribute];
-    return this.formatAttributeValue(value);
-  }
-
-  private formatAttributeValue(value: any): string | TemplateResult {
-    if (value === null) {
-      return "-";
-    }
-    // YAML handling
-    if (
-      (Array.isArray(value) && value.some((val) => val instanceof Object)) ||
-      (!Array.isArray(value) && value instanceof Object)
-    ) {
-      if (!jsYamlPromise) {
-        jsYamlPromise = import("js-yaml");
-      }
-      const yaml = jsYamlPromise.then((jsYaml) => jsYaml.safeDump(value));
-      return html` <pre>${until(yaml, "")}</pre> `;
-    }
-    // URL handling
-    if (typeof value === "string" && value.startsWith("http")) {
-      try {
-        // If invalid URL, exception will be raised
-        const url = new URL(value);
-        if (url.protocol === "http:" || url.protocol === "https:")
-          return html`<a target="_blank" rel="noreferrer" href="${value}"
-            >${value}</a
-          >`;
-      } catch (_) {
-        // Nothing to do here
-      }
-    }
-    return Array.isArray(value) ? value.join(", ") : value;
+    return formatAttributeValue(this.hass, value);
   }
 
   private expandedChanged(ev) {

src/panels/lovelace/cards/hui-entity-card.ts

@@ -18,6 +18,7 @@ import "../../../components/ha-card";
 import "../../../components/ha-icon";
 import { UNAVAILABLE_STATES } from "../../../data/entity";
 import { HomeAssistant } from "../../../types";
+import { formatAttributeValue } from "../../../util/hass-attributes-util";
 import { computeCardSize } from "../common/compute-card-size";
 import { findEntities } from "../common/find-entities";
 import { hasConfigOrEntityChanged } from "../common/has-changed";
@@ -124,8 +125,11 @@ export class HuiEntityCard extends LitElement implements LovelaceCard {
         <div class="info">
           <span class="value"
             >${"attribute" in this._config
-              ? stateObj.attributes[this._config.attribute!] ??
-                this.hass.localize("state.default.unknown")
+              ? formatAttributeValue(
+                  this.hass,
+                  stateObj.attributes[this._config.attribute!] ??
+                    this.hass.localize("state.default.unknown")
+                )
               : stateObj.attributes.unit_of_measurement
               ? formatNumber(stateObj.state, this.hass.locale)
               : computeStateDisplay(

src/panels/lovelace/special-rows/hui-attribute-row.ts

@@ -10,6 +10,7 @@ import { customElement, property, state } from "lit/decorators";
 import checkValidDate from "../../../common/datetime/check_valid_date";
 import { formatNumber } from "../../../common/string/format_number";
 import { HomeAssistant } from "../../../types";
+import { formatAttributeValue } from "../../../util/hass-attributes-util";
 import { hasConfigOrEntityChanged } from "../common/has-changed";
 import "../components/hui-generic-entity-row";
 import "../components/hui-timestamp-display";
@@ -72,7 +73,9 @@ class HuiAttributeRow extends LitElement implements LovelaceRow {
               ></hui-timestamp-display>`
             : typeof attribute === "number"
             ? formatNumber(attribute, this.hass.locale)
-            : attribute ?? "-"}
+            : attribute !== undefined
+            ? formatAttributeValue(this.hass, attribute)
+            : "-"}
           ${this._config.suffix}
         </div>
       </hui-generic-entity-row>

src/util/hass-attributes-util.ts

@@ -1,3 +1,14 @@
+import { html, TemplateResult } from "lit";
+import { until } from "lit/directives/until";
+import checkValidDate from "../common/datetime/check_valid_date";
+import { formatDate } from "../common/datetime/format_date";
+import { formatDateTimeWithSeconds } from "../common/datetime/format_date_time";
+import { isDate } from "../common/string/is_date";
+import { isTimestamp } from "../common/string/is_timestamp";
+import { HomeAssistant } from "../types";
+
+let jsYamlPromise: Promise<typeof import("js-yaml")>;
+
 const hassAttributeUtil = {
   DOMAIN_DEVICE_CLASS: {
     binary_sensor: [
@@ -130,3 +141,59 @@ export function formatAttributeName(value: string): string {
     .replace(/\bgps\b/g, "GPS");
   return value.charAt(0).toUpperCase() + value.slice(1);
 }
+
+export function formatAttributeValue(
+  hass: HomeAssistant,
+  value: any
+): string | TemplateResult {
+  if (value === null) {
+    return "-";
+  }
+
+  // YAML handling
+  if (
+    (Array.isArray(value) && value.some((val) => val instanceof Object)) ||
+    (!Array.isArray(value) && value instanceof Object)
+  ) {
+    if (!jsYamlPromise) {
+      jsYamlPromise = import("js-yaml");
+    }
+    const yaml = jsYamlPromise.then((jsYaml) => jsYaml.safeDump(value));
+    return html`<pre>${until(yaml, "")}</pre>`;
+  }
+
+  if (typeof value === "string") {
+    // URL handling
+    if (value.startsWith("http")) {
+      try {
+        // If invalid URL, exception will be raised
+        const url = new URL(value);
+        if (url.protocol === "http:" || url.protocol === "https:")
+          return html`<a target="_blank" rel="noreferrer" href="${value}"
+            >${value}</a
+          >`;
+      } catch (_) {
+        // Nothing to do here
+      }
+    }
+
+    // Date handling
+    if (isDate(value, true)) {
+      // Timestamp handling
+      if (isTimestamp(value)) {
+        const date = new Date(value);
+        if (checkValidDate(date)) {
+          return formatDateTimeWithSeconds(date, hass.locale);
+        }
+      }
+
+      // Value was not a timestamp, so only do date formatting
+      const date = new Date(value);
+      if (checkValidDate(date)) {
+        return formatDate(date, hass.locale);
+      }
+    }
+  }
+
+  return Array.isArray(value) ? value.join(", ") : value;
+}

test-mocha/common/string/is_date.ts

@@ -0,0 +1,12 @@
+import { assert } from "chai";
+import { isDate } from "../../../src/common/string/is_date";
+
+describe("isDate", () => {
+  assert.strictEqual(isDate("ABC"), false);
+
+  assert.strictEqual(isDate("2021-02-03", false), true);
+  assert.strictEqual(isDate("2021-02-03", true), true);
+
+  assert.strictEqual(isDate("2021-05-25T19:23:52+00:00", true), true);
+  assert.strictEqual(isDate("2021-05-25T19:23:52+00:00", false), false);
+});