feat: allow closure on formatColumn

Author: yajra

src/DataTableAbstract.php

@@ -176,8 +176,6 @@ public static function create($source)
      * @param  string|array  $columns
      * @param  string|\Yajra\DataTables\Contracts\Formatter  $formatter
      * @return $this
-     *
-     * @throws \Yajra\DataTables\Exceptions\Exception
      */
     public function formatColumn($columns, $formatter): static
     {
@@ -193,7 +191,29 @@ public function formatColumn($columns, $formatter): static
             return $this;
         }
 
-        throw new Exception('$formatter must be an instance of '.Formatter::class);
+        if (is_callable($formatter)) {
+            foreach ((array) $columns as $column) {
+                $this->addColumn(
+                    $column.'_formatted',
+                    function ($row) use ($column, $formatter) {
+                        return $formatter(data_get($row, $column), $row);
+                    }
+                );
+            }
+
+            return $this;
+        }
+
+        foreach ((array) $columns as $column) {
+            $this->addColumn(
+                $column.'_formatted',
+                function ($row) use ($column) {
+                    return data_get($row, $column);
+                }
+            );
+        }
+
+        return $this;
     }
 
     /**