1 files changed, 44 insertions, 0 deletions
diff --git a/static/js/decodeMail.js b/static/js/decodeMail.js
new file mode 100644
index 0000000..f26ac68
--- /dev/null
+++ b/static/js/decodeMail.js
@@ -0,0 +1,44 @@
+(function () {
+    'use strict';
+
+    // Utility function: Base64 Decoding.
+    function decodeBase64(encodedString) {
+        try {
+            // Can't use atob() directly because it doesn't support non-ascii characters.
+            // And non-ascii characters are allowed in email addresses and domains.
+            // See https://en.wikipedia.org/wiki/Email_address#Internationalization
+            // Code below adapted from Jackie Han: https://stackoverflow.com/a/64752311
+            const byteString = atob(encodedString);
+
+            // Convert byteString to an array of char codes.
+            const charCodes = [...byteString].map((char) => char.charCodeAt(0));
+
+            // Use TypedArray.prototype.set() to copy the char codes into a Uint8Array.
+            const bytes = new Uint8Array(charCodes.length);
+            bytes.set(charCodes);
+
+            const decoder = new TextDecoder('utf-8');
+            return decoder.decode(bytes);
+        } catch (e) {
+            console.error('Failed to decode Base64 string: ', e);
+            return null;
+        }
+    }
+
+    // Utility function: Update href of an element with a decoded email.
+    function updateEmailHref(element) {
+        const encodedEmail = element.getAttribute('data-encoded-email');
+        const decodedEmail = decodeBase64(encodedEmail);
+
+        if (decodedEmail) {
+            element.setAttribute('href', `mailto:${decodedEmail}`);
+        } else {
+            // If the decoding fails, hide the email link.
+            element.style.display = 'none';
+        }
+    }
+
+    // Fetch and process email elements with the "data-encoded-email" attribute.
+    const encodedEmailElements = document.querySelectorAll('[data-encoded-email]');
+    encodedEmailElements.forEach(updateEmailHref);
+})();