Code snippet: fallback-values-for-address.php

sample-code-snippets/misc/fallback-values-for-address.php

@@ -0,0 +1,27 @@
+<?php
+
+/**
+ * Mailchimp always expects a full and complete address when you use a field of type "address"
+ *
+ * This snippet will allow you to submit a partial address and fill missing fields with fallback values.
+ * Fill sensible fallback data for your region, especially ZIP might expect a different value depending on your locale.
+ */
+
+add_filter('mc4wp_format_field_value', function ($value, $field_type) {
+    if ($field_type === 'address') {
+        $value = is_array($value) ? $value : [];
+
+        $fallbacks = [
+            'addr1'   => 'N/A',
+            'city'    => 'N/A',
+            'state'   => 'N/A',
+            'zip'     => '00000',
+        ];
+
+        // Fill missing values from fallbacks
+        foreach ($fallbacks as $k => $fallback) {
+            $value[$k] = isset($value[$k]) && $value[$k] !== '' ? $value[$k] : $fallback;
+        }
+    }
+    return $value;
+}, 10, 2);