modules/uc_restrict_qty/uc_restrict_qty.module

<?php

/**
 * @file
 * Restrict the quantity on specified products so that only one may be purchased
 * at a time.
 *
 * Sponsored by Flat World Knowledge - http://www.flatworldknowledge.com
 */

/**
 * Implementation of hook_product_feature().
 */
function uc_restrict_qty_product_feature() {
  $features[] = array(
    'id' => 'restrict_qty',
    'title' => t('Restrict Qty.'),
    'callback' => 'uc_restrict_qty_feature_form',
  );

  return $features;
}

// Display the settings form for the node access product feature.
function uc_restrict_qty_feature_form($node, $feature) {
  if (empty($feature)) {
    // It's not necessary to add more than one of these features at the moment.
    if ($result = db_result(db_query("SELECT COUNT(*) FROM {uc_product_features} WHERE nid = %d AND fid = '%s'", $node->nid, 'restrict_qty'))) {
      drupal_set_message(t('Adding more than one Restrict Qty. does nothing for now.'));
    }
    else {
      $data = array(
        'pfid' => db_next_id('{uc_product_features}_pfid'),
        'nid' => $node->nid,
        'fid' => 'restrict_qty',
        'description' => t('Users may only purchase one of this product at a time.'),
      );
      drupal_goto(uc_product_feature_save($data));
    }
  }
  else {
    drupal_set_message(t('There are no settings to edit for Restrict Qty. features.'));
  }

  drupal_goto('node/'. $node->nid .'/edit/features');
}

/**
 * Implementation of hook_add_to_cart_data().
 */
function uc_restrict_qty_add_to_cart_data($form_values) {
  return array('restrict_qty' => uc_restrict_qty_count($form_values['nid']));
}

/**
 * Implementation of hook_cart_item().
 */
function uc_restrict_qty_cart_item($op, &$item) {
  if ($op == 'load') {
    // If this item has a quantity restriction on it...
    if ($item->data['restrict_qty'] > 0 && $item->qty > 1) {
      // Reduce the quantity to 1 if necessary. 
      db_query("UPDATE {uc_cart_products} SET qty = 1 WHERE cart_id = '%s' AND nid = %d AND data = '%s'", uc_cart_get_id(), $item->nid, serialize($item->data));
      $item->qty = 1;
    }
  }
}

/**
 * Implementation of hook_form_alter().
 */
function uc_restrict_qty_form_alter($form_id, &$form) {
  // Disable the appropriate Qty. fields on the cart view form.
  if ($form_id == 'uc_cart_view_form') {
    foreach ($form['items'] as $key => $value) {
      $data = unserialize($value['data']['#value']);

      // If this item has a quantity restriction on it...
      if ($data['restrict_qty'] > 0) {
        $form['items'][$key]['qty']['#theme'] = 'restrict_qty_field';
      }
    }
  }
}

// Themes cart Qty. boxes so they can't be changed.
function theme_restrict_qty_field($element) {
  return check_plain($element['#value']);
}

// Returns the number of restrict_qty features on a product node.
function uc_restrict_qty_count($nid) {
  return db_result(db_query("SELECT COUNT(*) FROM {uc_product_features} WHERE nid = %d AND fid = '%s'", $nid, 'restrict_qty'));
}
1	<?php
2
3	/**
4	* @file
5	* Restrict the quantity on specified products so that only one may be purchased
6	* at a time.
7	*
8	* Sponsored by Flat World Knowledge - http://www.flatworldknowledge.com
9	*/
10
11	/**
12	* Implementation of hook_product_feature().
13	*/
14	function uc_restrict_qty_product_feature() {
15	$features[] = array(
16	'id' => 'restrict_qty',
17	'title' => t('Restrict Qty.'),
18	'callback' => 'uc_restrict_qty_feature_form',
19	);
20
21	return $features;
22	}
23
24	// Display the settings form for the node access product feature.
25	function uc_restrict_qty_feature_form($node, $feature) {
26	if (empty($feature)) {
27	// It's not necessary to add more than one of these features at the moment.
28	if ($result = db_result(db_query("SELECT COUNT(*) FROM {uc_product_features} WHERE nid = %d AND fid = '%s'", $node->nid, 'restrict_qty'))) {
29	drupal_set_message(t('Adding more than one Restrict Qty. does nothing for now.'));
30	}
31	else {
32	$data = array(
33	'pfid' => db_next_id('{uc_product_features}_pfid'),
34	'nid' => $node->nid,
35	'fid' => 'restrict_qty',
36	'description' => t('Users may only purchase one of this product at a time.'),
37	);
38	drupal_goto(uc_product_feature_save($data));
39	}
40	}
41	else {
42	drupal_set_message(t('There are no settings to edit for Restrict Qty. features.'));
43	}
44
45	drupal_goto('node/'. $node->nid .'/edit/features');
46	}
47
48	/**
49	* Implementation of hook_add_to_cart_data().
50	*/
51	function uc_restrict_qty_add_to_cart_data($form_values) {
52	return array('restrict_qty' => uc_restrict_qty_count($form_values['nid']));
53	}
54
55	/**
56	* Implementation of hook_cart_item().
57	*/
58	function uc_restrict_qty_cart_item($op, &$item) {
59	if ($op == 'load') {
60	// If this item has a quantity restriction on it...
61	if ($item->data['restrict_qty'] > 0 && $item->qty > 1) {
62	// Reduce the quantity to 1 if necessary.
63	db_query("UPDATE {uc_cart_products} SET qty = 1 WHERE cart_id = '%s' AND nid = %d AND data = '%s'", uc_cart_get_id(), $item->nid, serialize($item->data));
64	$item->qty = 1;
65	}
66	}
67	}
68
69	/**
70	* Implementation of hook_form_alter().
71	*/
72	function uc_restrict_qty_form_alter($form_id, &$form) {
73	// Disable the appropriate Qty. fields on the cart view form.
74	if ($form_id == 'uc_cart_view_form') {
75	foreach ($form['items'] as $key => $value) {
76	$data = unserialize($value['data']['#value']);
77
78	// If this item has a quantity restriction on it...
79	if ($data['restrict_qty'] > 0) {
80	$form['items'][$key]['qty']['#theme'] = 'restrict_qty_field';
81	}
82	}
83	}
84	}
85
86	// Themes cart Qty. boxes so they can't be changed.
87	function theme_restrict_qty_field($element) {
88	return check_plain($element['#value']);
89	}
90
91	// Returns the number of restrict_qty features on a product node.
92	function uc_restrict_qty_count($nid) {
93	return db_result(db_query("SELECT COUNT(*) FROM {uc_product_features} WHERE nid = %d AND fid = '%s'", $nid, 'restrict_qty'));
94	}