developer/examples/nodeapi_example.module

<?php
// $Id: nodeapi_example.module,v 1.8 2008/09/15 07:26:20 davereid Exp $

/**
 * @file
 * This is an example outlining how a module can be used to extend existing
 * content types.
 *
 * We will add the ability for each node to have a "rating," which will be a
 * number from one to five.
 */

/**
 * Implementation of hook_form_alter().
 *
 * By implementing this hook, we're able to modify any form. We'll only make
 * changes to two types: a node's content type configuration and edit forms.
 *
 * We need to have a way for administrators to indicate which content types
 * should have our rating field added. This is done by inserting a checkbox in
 * the node's content type configuration page.
 */
function nodeapi_example_form_alter(&$form, $form_state, $form_id) {
  if ($form_id == 'node_type_form' && isset($form['identity']['type'])) {
    // Alter the node type's configuration form to add our setting. We don't
    // need to worry about saving this value back to the variable, the form
    // we're altering will do it for us.
    $form['workflow']['nodeapi_example'] = array(
      '#type' => 'radios',
      '#title' => t('NodeAPI Example Rating'),
      '#default_value' => variable_get('nodeapi_example_'. $form['#node_type']->type, 0),
      '#options' => array(0 => t('Disabled'), 1 => t('Enabled')),
      '#description' => t('Should this node have a rating attached to it?'),
    );
  }
  // If the type and node field are set this may be a node edit form.
  elseif (isset($form['type']) && isset($form['#node']) && $form['type']['#value'] .'_node_form' == $form_id) {
    // If the rating is enabled for this node type, we insert our control
    // into the form.
    $node = $form['#node'];
    if (variable_get('nodeapi_example_'. $form['type']['#value'], 0)) {
      $form['nodeapi_example_rating'] = array(
        '#type' => 'select',
        '#title' => t('Rating'),
        '#default_value' => isset($node->nodeapi_example_rating) ? $node->nodeapi_example_rating : '',
        '#options' => array(0 => t('Unrated'), 1, 2, 3, 4, 5),
        '#required' => TRUE,
        '#weight' => 0,
      );
    }
  }
}

/**
 * Implementation of hook_nodeapi().
 *
 * We will implement several node API operations here. This hook allows us to
 * act on all major node operations, so we can manage our additional data
 * appropriately.
 */
function nodeapi_example_nodeapi(&$node, $op, $teaser, $page) {
  switch ($op) {
    // When the content editing form is submitted, we need to validate the input
    // to make sure the user made a selection, since we are requiring the rating
    // field. We have to check that the value has been set to avoid showing an
    // error message when a new blank form is presented. Calling form_set_error()
    // when the field is set but zero ensures not only that an error message is
    // presented, but also that the user must correct the error before being able
    // to submit the node.
    case 'validate':
      if (variable_get('nodeapi_example_'. $node->type, TRUE)) {
        if (isset($node->nodeapi_example_rating) && !$node->nodeapi_example_rating) {
          form_set_error('nodeapi_example_rating', t('You must rate this content.'));
        }
      }
      break;

    // Now we need to take care of loading one of the extended nodes from the
    // database. An array containing our extra field needs to be returned.
    case 'load':
      $rating = db_result(db_query('SELECT rating FROM {nodeapi_example} WHERE nid = %d', $node->nid));
      return array('nodeapi_example_rating' => $rating);
      break;

    // Insert is called after the node has been validated and saved to the
    // database. It gives us a chance to create our own record in the database.
    case 'insert':
      db_query('INSERT INTO {nodeapi_example} (nid, rating) VALUES (%d, %d)', $node->nid, $node->nodeapi_example_rating);
      break;

    // Update is called when an existing node has been changed. Here, we use a
    // DELETE then an INSERT rather than an UPDATE. The reason is that a node
    // created before this module was installed won't already have a rating
    // saved so there would be nothing to update.
    case 'update':
      db_query('DELETE FROM {nodeapi_example} WHERE nid = %d', $node->nid);
      db_query('INSERT INTO {nodeapi_example} (nid, rating) VALUES (%d, %d)', $node->nid, $node->nodeapi_example_rating);
      break;

    // Delete is called whn the node is being deleted, it gives us a chance
    // to delete the rating too.
    case 'delete':
      db_query('DELETE FROM {nodeapi_example} WHERE nid = %d', $node->nid);
      break;

    // Finally, we need to take care of displaying our rating when the node is
    // viewed. This operation is called after the node has already been prepared
    // into HTML and filtered as necessary, so we know we are dealing with an
    // HTML teaser and body. We will inject our additional information at the front
    // of the node copy.
    //
    // Using nodeapi('view') is more appropriate than using a filter here, because
    // filters transform user-supplied content, whereas we are extending it with
    // additional information.
    case 'view':
      $node->content['nodeapi_example'] = array(
        '#value' => theme('nodeapi_example_rating', $node->nodeapi_example_rating),
        '#weight' => -1,
      );
      break;
  }
}

/**
 * Implementation of hook_theme().
 *
 * This lets us tell Drupal about our theme functions and their arguments.
 */
function nodeapi_example_theme() {
  return array(
    'nodeapi_example_rating' => array(
      'arguments' => array('rating'),
    ),
  );
}

/**
 * A custom theme function.
 *
 * By using this function to format our rating, themes can override this presentation
 * if they wish; for example, they could provide a star graphic for the rating. We
 * also wrap the default presentation in a CSS class that is prefixed by the module
 * name. This way, style sheets can modify the output without requiring theme code.
 */
function theme_nodeapi_example_rating($rating) {
  $options = array(
    0 => t('Unrated'),
    1 => t('Poor'),
    2 => t('Needs improvement'),
    3 => t('Acceptable'),
    4 => t('Good'),
    5 => t('Excellent'));
  $output = '<div class="nodeapi_example_rating">';
  $output .= t('Rating: %rating', array('%rating' => $options[(int) $rating]));
  $output .= '</div>';
  return $output;
}

1	<?php
2	// $Id: nodeapi_example.module,v 1.8 2008/09/15 07:26:20 davereid Exp $
3
4	/**
5	* @file
6	* This is an example outlining how a module can be used to extend existing
7	* content types.
8	*
9	* We will add the ability for each node to have a "rating," which will be a
10	* number from one to five.
11	*/
12
13	/**
14	* Implementation of hook_form_alter().
15	*
16	* By implementing this hook, we're able to modify any form. We'll only make
17	* changes to two types: a node's content type configuration and edit forms.
18	*
19	* We need to have a way for administrators to indicate which content types
20	* should have our rating field added. This is done by inserting a checkbox in
21	* the node's content type configuration page.
22	*/
23	function nodeapi_example_form_alter(&$form, $form_state, $form_id) {
24	if ($form_id == 'node_type_form' && isset($form['identity']['type'])) {
25	// Alter the node type's configuration form to add our setting. We don't
26	// need to worry about saving this value back to the variable, the form
27	// we're altering will do it for us.
28	$form['workflow']['nodeapi_example'] = array(
29	'#type' => 'radios',
30	'#title' => t('NodeAPI Example Rating'),
31	'#default_value' => variable_get('nodeapi_example_'. $form['#node_type']->type, 0),
32	'#options' => array(0 => t('Disabled'), 1 => t('Enabled')),
33	'#description' => t('Should this node have a rating attached to it?'),
34	);
35	}
36	// If the type and node field are set this may be a node edit form.
37	elseif (isset($form['type']) && isset($form['#node']) && $form['type']['#value'] .'_node_form' == $form_id) {
38	// If the rating is enabled for this node type, we insert our control
39	// into the form.
40	$node = $form['#node'];
41	if (variable_get('nodeapi_example_'. $form['type']['#value'], 0)) {
42	$form['nodeapi_example_rating'] = array(
43	'#type' => 'select',
44	'#title' => t('Rating'),
45	'#default_value' => isset($node->nodeapi_example_rating) ? $node->nodeapi_example_rating : '',
46	'#options' => array(0 => t('Unrated'), 1, 2, 3, 4, 5),
47	'#required' => TRUE,
48	'#weight' => 0,
49	);
50	}
51	}
52	}
53
54	/**
55	* Implementation of hook_nodeapi().
56	*
57	* We will implement several node API operations here. This hook allows us to
58	* act on all major node operations, so we can manage our additional data
59	* appropriately.
60	*/
61	function nodeapi_example_nodeapi(&$node, $op, $teaser, $page) {
62	switch ($op) {
63	// When the content editing form is submitted, we need to validate the input
64	// to make sure the user made a selection, since we are requiring the rating
65	// field. We have to check that the value has been set to avoid showing an
66	// error message when a new blank form is presented. Calling form_set_error()
67	// when the field is set but zero ensures not only that an error message is
68	// presented, but also that the user must correct the error before being able
69	// to submit the node.
70	case 'validate':
71	if (variable_get('nodeapi_example_'. $node->type, TRUE)) {
72	if (isset($node->nodeapi_example_rating) && !$node->nodeapi_example_rating) {
73	form_set_error('nodeapi_example_rating', t('You must rate this content.'));
74	}
75	}
76	break;
77
78	// Now we need to take care of loading one of the extended nodes from the
79	// database. An array containing our extra field needs to be returned.
80	case 'load':
81	$rating = db_result(db_query('SELECT rating FROM {nodeapi_example} WHERE nid = %d', $node->nid));
82	return array('nodeapi_example_rating' => $rating);
83	break;
84
85	// Insert is called after the node has been validated and saved to the
86	// database. It gives us a chance to create our own record in the database.
87	case 'insert':
88	db_query('INSERT INTO {nodeapi_example} (nid, rating) VALUES (%d, %d)', $node->nid, $node->nodeapi_example_rating);
89	break;
90
91	// Update is called when an existing node has been changed. Here, we use a
92	// DELETE then an INSERT rather than an UPDATE. The reason is that a node
93	// created before this module was installed won't already have a rating
94	// saved so there would be nothing to update.
95	case 'update':
96	db_query('DELETE FROM {nodeapi_example} WHERE nid = %d', $node->nid);
97	db_query('INSERT INTO {nodeapi_example} (nid, rating) VALUES (%d, %d)', $node->nid, $node->nodeapi_example_rating);
98	break;
99
100	// Delete is called whn the node is being deleted, it gives us a chance
101	// to delete the rating too.
102	case 'delete':
103	db_query('DELETE FROM {nodeapi_example} WHERE nid = %d', $node->nid);
104	break;
105
106	// Finally, we need to take care of displaying our rating when the node is
107	// viewed. This operation is called after the node has already been prepared
108	// into HTML and filtered as necessary, so we know we are dealing with an
109	// HTML teaser and body. We will inject our additional information at the front
110	// of the node copy.
111	//
112	// Using nodeapi('view') is more appropriate than using a filter here, because
113	// filters transform user-supplied content, whereas we are extending it with
114	// additional information.
115	case 'view':
116	$node->content['nodeapi_example'] = array(
117	'#value' => theme('nodeapi_example_rating', $node->nodeapi_example_rating),
118	'#weight' => -1,
119	);
120	break;
121	}
122	}
123
124	/**
125	* Implementation of hook_theme().
126	*
127	* This lets us tell Drupal about our theme functions and their arguments.
128	*/
129	function nodeapi_example_theme() {
130	return array(
131	'nodeapi_example_rating' => array(
132	'arguments' => array('rating'),
133	),
134	);
135	}
136
137	/**
138	* A custom theme function.
139	*
140	* By using this function to format our rating, themes can override this presentation
141	* if they wish; for example, they could provide a star graphic for the rating. We
142	* also wrap the default presentation in a CSS class that is prefixed by the module
143	* name. This way, style sheets can modify the output without requiring theme code.
144	*/
145	function theme_nodeapi_example_rating($rating) {
146	$options = array(
147	0 => t('Unrated'),
148	1 => t('Poor'),
149	2 => t('Needs improvement'),
150	3 => t('Acceptable'),
151	4 => t('Good'),
152	5 => t('Excellent'));
153	$output = '<div class="nodeapi_example_rating">';
154	$output .= t('Rating: %rating', array('%rating' => $options[(int) $rating]));
155	$output .= '</div>';
156	return $output;
157	}
158