1 files changed, 69 insertions, 0 deletions
diff --git a/lib/vnlib.browser/src/session/cookies.ts b/lib/vnlib.browser/src/session/cookies.ts
new file mode 100644
index 0000000..0e3e613
--- /dev/null
+++ b/lib/vnlib.browser/src/session/cookies.ts
@@ -0,0 +1,69 @@
+// Copyright (c) 2023 Vaughn Nugent
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+import { defer, isEqual } from 'lodash-es'
+import { computed, ref, type Ref } from 'vue'
+import Cookies from 'universal-cookie'
+
+export interface CookieMonitor<T> {
+    readonly cookieValue: Readonly<Ref<T>>;
+    readonly enabled: Readonly<Ref<boolean>>;
+}
+
+export type CookieValueConveter<T> = (value: string) => T;
+
+/**
+ * Creates a reactive wrapper that monitors a single cookie value for changes
+ * @param enabled A ref that indicates if the cookie should be monitored
+ * @param cookieName The name of the cookie to monitor
+ * @param converter An optional converter function to convert the cookie value to a different type 
+ */
+export const createCookieMonitor = <T = string>(enabled: Ref<boolean>, cookieName: Ref<string | undefined>, converter?: CookieValueConveter<T>) : CookieMonitor<T> => {
+
+    //Set default converter
+    converter ??= (value: string) => value as unknown as T;
+
+    const cookieJar = new Cookies();
+    const cookieRef = ref<string>('');
+    const cookieValue = computed<T>(() => converter!(cookieRef.value));
+    
+    //Store last value to avoid unnecessary updates
+    let lastValue = '';
+
+    const get = (): string => cookieJar.get<string>(cookieName.value || '', { doNotParse: true });
+
+    const checkAndUpdateCookie = () => {
+        if (!enabled.value) {
+            return;
+        }
+        //Get the new cookeie value
+        const newValue = get()
+        if (!isEqual(newValue, lastValue)) {
+            lastValue = cookieRef.value = newValue
+        }
+    }
+
+    //Watch for changes to the cookie and update the ref only if its enabled
+    cookieJar.addChangeListener(() => defer(checkAndUpdateCookie))
+
+    //Initial cookie check
+    checkAndUpdateCookie()
+
+    return { cookieValue , enabled }
+}
+\ No newline at end of file