order.module

<?php
/**
 * Hook menu()
 * @return unknown_type
 */
function order_menu(){
	$items = array();
	$items['admin/settings/order'] = array(
    'title' => 'Orders setting',
    'description' => 'Choose what node type can order',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('order_admin_setting'),
    'access arguments' => array('admin setting order'),
    'type' => MENU_NORMAL_ITEM,
    'file' => 'order.admin.inc',
	);
	return $items;
}
/**
 * Order form
 * @param $form_state
 * @param $node
 * @return unknown_type
 */
function order_form($form_state, $node){
	$node = (object)$node;
	$form = array();
	$form['order'] = array(
	  '#title' => 'Orders',
	  '#type'  => 'fieldset',
	  '#description' => 'Order product',
	  '#collapsible' => TRUE,
    '#collapsed' => TRUE,
	  '#weight' => -7,
	);
	$form['order']['fullname'] = array(
	  '#title' => t('Full name'),
	  '#type' => 'textfield',
	  '#description' => t('Enter your name.'),
	  '#required' => TRUE,
	  '#weight' => -6,
	);
	$form['order']['address'] = array(
    '#title' => t('Address'),
    '#type' => 'textfield',
	  '#required' => TRUE,
    '#description' => t('Enter your address.'),
	  '#weight' => -5,
	);
	$form['order']['email'] = array(
    '#title' => t('Email'),
    '#type' => 'textfield',
    '#description' => t('Enter your email.'),
	  '#required' => TRUE,
	  '#weight' => -4,
	);
	$form['order']['phone'] = array(
    '#title' => t('Phone'),
    '#type' => 'textfield',
    '#description' => t('Enter your phone.'),
	  '#weight' => -3,
	);
	 
	$form['order']['amount'] = array(
    '#title' => t('Amount'),
    '#type' => 'textfield',
	  '#default' => 1,
	  '#required' => TRUE,
    '#description' => t('Amount of product.'),
	  '#weight' => -2,
	);
	$form['order']['message'] = array(
    '#title' => t('Message'),
    '#type' => 'textarea',
    '#description' => t('Enter your message.'),
	  '#weight' => -1,
	);
	$form['order']['node_title'] = array(
    '#type' => 'value',
    '#value' => $node->title,
	);
	$form['order']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
	  '#weight' => 10,
	);
	return $form;
}

function order_theme(){
  return array(
    'order_form'=> array('arguments'=> 'form'),
  );
}

function theme_order_form($form){
	
	$form['order']['captcha'] = $form['captcha'];
	unset($form['captcha']);
	return drupal_render($form);
}

function order_form_validate(&$form, $form_state){
  if (!valid_email_address($form_state['values']['email'])) {
    form_set_error('email',t('The e-mail address %mail is not valid.', array('%mail' => $form_state['values']['email'])));
  }
}

function order_form_submit(&$form, $form_state){
	$params = $form_state['values'];
	drupal_mail('order', 'order_mail', variable_get('order_admin_mail','tquoc229@yahoo.com'), language_default(), $params);
	drupal_mail('order', 'order_copy', $params['email'], language_default(), $params);
	watchdog('mail', '%name-from sent an e-mail order.', array('%name-from' => $params['name'] ." [". $params['email']."]"));
  drupal_set_message(t('Your order has been sent.'));
}

function order_mail($key, &$message, $params){
	
	
	switch($key){
		case 'order_mail':
			$message['subject'].= t('Customer\'s order at !site',array('!site'=> variable_get('site_name','website')));
      $message['body'][] = t("============= Customer info ===================== \n");
      $message['body'][] = t('Fullname: %fullname',array('%fullname'=>$params['fullname']));
      $message['body'][] = t('Address: %address',array('%address'=>$params['address']));
      $message['body'][] = t('Email: %email',array('%email'=>$params['email']));
      $message['body'][] = t('Phone: %phone',array('%phone'=>$params['phone']));
      $message['body'][] = t('Message: %message',array('%message'=>$params['message']));
			$message['body'][] = t("============= Order info ===================== \n");
      $message['body'][] = t('Product: %product',array('%product'=>$params['node_title']));
      $message['body'][] = t('Amount: %amount',array('%amount'=>$params['amount']));
      $message['body'][] = t('Time: %time',array('%time'=> format_date(time())));
      $message['body'][] = t("================================== \n");
      break;
		case 'order_copy':
			$message['subject'].= t('Your order at !site',array('!site'=> variable_get('site_name','website')));
			$message['body'][] = t('Hi %fullname',array('%fullname'=>$params['fullname']));
			$message['body'][] = t('Thanks for your order at !site_name',array('!site_name'=>url('<front>',array('absolute'=>TRUE))));
			$message['body'][] = t("============= Your order info ===================== \n");
			$message['body'][] = t('Product: %product',array('%product'=>$params['node_title']));
			$message['body'][] = t('Amount: %amount',array('%amount'=>$params['amount']));
			$message['body'][] = t('Time: %time',array('%time'=> format_date(time())));
			$message['body'][] = t("================================== \n");
			break;
	}
}
/**
 * Implement hook nodeapi
 * @param $node
 * @param $op
 * @param $teaser
 * @return unknown_type
 */
function order_nodeapi(&$node, $op, $teaser){
	switch ($op){
		case 'load':
			$output = array();
			$node_types = variable_get('order_node_types',array());
			if($node_types[$node->type]){
			  $output['order'] = drupal_get_form('order_form',$node);
    		return $output;
			}
			break;
		case 'view':
			if (!$teaser) {
				$node->content['order'] = array(
              '#value' => $node->order,
              '#weight' => 50,
				);
			}
			break;
	}
}