add new form validation rules in safecracker_submit_entry_start

gistfile1.aw

<?php

public function safecracker_submit_entry_start()
{
	$my_custom_rules = array(
		'my_field_1' => 'max_length[5]',
		'my_field_2' => 'required|max_length[10]',
	);

	foreach ($my_custom_rules as $field_name => $field_rules)
	{
		if ( ! isset($this->EE->safecracker->custom_fields[$field_name]))
		{
			//field doesn't exist in this channel
			continue;
		}

		$field = $this->EE->safecracker->custom_fields[$field_name];

		$field_rules = explode('|', $field_rules);

		if ( ! in_array('call_field_validation['.$field['field_id'].']', $field_rules))
		{
			array_unshift($field_rules, 'call_field_validation['.$field['field_id'].']');
		}

		if ($field['field_required'] == 'y' && ! in_array('required', $field_rules))
		{
			array_unshift($field_rules, 'required');
		}

		$this->EE->form_validation->set_rules($field['field_name'], $field['field_label'], implode('|', $field_rules));
	}
}