form.field.Text: emptyValue config #4953

Author: tobiu

src/form/field/Text.mjs

@@ -75,6 +75,11 @@ class Text extends Base {
          * @member {String[]|null} disabledChars_=null
          */
         disabledChars_: null,
+        /**
+         * Configure the value of empty fields. null or an empty string is recommended.
+         * @member {String|null} emptyValue=null
+         */
+        emptyValue: null,
         /**
          * @member {String|null} error_=null
          */
@@ -950,6 +955,21 @@ class Text extends Base {
         return value
     }
 
+    /**
+     * Triggered before the value config gets changed
+     * @param {String|null} value
+     * @param {String|null} oldValue
+     * @returns {String|null}
+     * @protected
+     */
+    beforeSetValue(value, oldValue) {
+        if (value === null || value === '') {
+            return this.emptyValue
+        }
+
+        return value
+    }
+
     /**
      * Resets the field to its original value or null depending on the clearToOriginalValue config
      */