Make URLs created by filter form a lot shorter

assets/controllers/helpers/form_cleanup_controller.js

@@ -0,0 +1,43 @@
+import {Controller} from "@hotwired/stimulus";
+
+/**
+ * Purpose of this controller is to clean up the form before it is finally submitted. This means empty fields get disabled, so they are not submitted.
+ * This is especially useful for GET forms, to prevent very long URLs
+ */
+export default class extends Controller {
+
+    /**
+     * Call during the submit event of the form. This will disable all empty fields, so they are not submitted.
+     * @param event
+     */
+    submit(event) {
+        /** Find the form this event belongs to */
+        /** @type {HTMLFormElement} */
+        const form = event.target.closest('form');
+
+        for(const element of form.elements) {
+            if(! element.value) {
+                element.disabled = true;
+            }
+
+            //Workaround for tristate checkboxes which use a hidden field to store the value
+            if ((element.type === 'hidden' || element.type === 'checkbox') && element.value === 'indeterminate') {
+                element.disabled = true;
+            }
+        }
+    }
+
+    /**
+     * Submits the form with all form elements disabled, so they are not submitted. This is useful for GET forms, to reset the form to not filled state.
+     * @param event
+     */
+    clearAll(event)
+    {
+        const form = event.target.closest('form');
+        for(const element of form.elements) {
+            element.disabled = true;
+        }
+
+        form.submit();
+    }
+}