feat: allow templating in the Signal notificaiton provider (#6989)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Frank Elsinga <frank@elsinga.de>

server/notification-providers/signal.js

@@ -11,8 +11,14 @@ class Signal extends NotificationProvider {
         const okMsg = "Sent Successfully.";
 
         try {
+            let message = msg;
+
+            if (notification.signalUseTemplate) {
+                message = await this.renderTemplate(notification.signalTemplate, msg, monitorJSON, heartbeatJSON);
+            }
+
             let data = {
-                message: msg,
+                message,
                 number: notification.signalNumber,
                 recipients: notification.signalRecipients.replace(/\s/g, "").split(","),
             };

src/components/notifications/Signal.vue

@@ -52,4 +52,48 @@
             </p>
         </div>
     </div>
+
+    <div class="mb-3">
+        <div class="form-check form-switch">
+            <input v-model="$parent.notification.signalUseTemplate" class="form-check-input" type="checkbox" />
+            <label class="form-check-label">{{ $t("signalUseTemplate") }}</label>
+        </div>
+
+        <div class="form-text">
+            {{ $t("signalUseTemplateDescription") }}
+        </div>
+    </div>
+
+    <template v-if="$parent.notification.signalUseTemplate">
+        <div class="mb-3">
+            <label class="form-label" for="signal-template">{{ $t("Message Template") }}</label>
+            <TemplatedTextarea
+                id="signal-template"
+                v-model="$parent.notification.signalTemplate"
+                :required="true"
+                :placeholder="signalTemplatedTextareaPlaceholder"
+            ></TemplatedTextarea>
+        </div>
+    </template>
 </template>
+
+<script>
+import TemplatedTextarea from "../TemplatedTextarea.vue";
+
+export default {
+    components: {
+        TemplatedTextarea,
+    },
+    computed: {
+        signalTemplatedTextareaPlaceholder() {
+            return this.$t("Example:", [
+                `
+Signal Alert{% if monitorJSON %} - {{ monitorJSON['name'] }}{% endif %}
+
+{{ msg }}
+            `,
+            ]);
+        },
+    },
+};
+</script>

src/lang/en.json

@@ -863,6 +863,8 @@
     "Remove domain": "Remove domain '{0}'",
     "Icon Emoji": "Icon Emoji",
     "signalImportant": "IMPORTANT: You cannot mix groups and numbers in recipients!",
+    "signalUseTemplate": "Use custom message template",
+    "signalUseTemplateDescription": "If enabled, the message will be sent using a custom template. You can use Liquid templating to customize the notification format.",
     "aboutWebhooks": "More info about Webhooks on: {0}",
     "aboutJiraCloudId": "More info about Jira Cloud ID: {0}",
     "see Jira Cloud Docs": "see Jira Cloud Docs",