handlers/views_handler_relationship.inc

   1 <?php
   2 /**
   3  * @file
   4  * Views' relationship handlers.
   5  */
   6
   7 /**
   8  * @defgroup views_relationship_handlers Views' relationship handlers
   9  * @{
  10  * Handlers to tell Views how to create alternate relationships.
  11  */
  12
  13 /**
  14  * Simple relationship handler that allows a new version of the primary table
  15  * to be linked in.
  16  *
  17  * The base relationship handler can only handle a single join. Some relationships
  18  * are more complex and might require chains of joins; for those, you must
  19  * utilize a custom relationship handler.
  20  *
  21  * Definition items:
  22  * - base: The new base table this relationship will be adding. This does not
  23  *   have to be a declared base table, but if there are no tables that
  24  *   utilize this base table, it won't be very effective.
  25  * - base field: The field to use in the relationship; if left out this iwll be
  26  *   assumed to be the primary field.
  27  * - relationship table: The actual table this relationship operates against.
  28  *   This is analogous to using a 'table' override.
  29  * - relationship field: The actual field this relationsihp operates against.
  30  *   This is analogous to using a 'real field' override.
  31  * - label: The default label to provide for this relationship, which is
  32  *   shown in parentheses next to any field/sort/filter/argument that uses
  33  *   the relationship.
  34  */
  35 class views_handler_relationship extends views_handler {
  36   /**
  37    * Init handler to let relationships live on tables other than
  38    * the table they operate on.
  39    */
  40   function init(&$view, $options) {
  41     parent::init($view, $options);
  42     if (isset($this->definition['relationship table'])) {
  43       $this->table = $this->definition['relationship table'];
  44     }
  45     if (isset($this->definition['relationship field'])) {
  46       $this->field = $this->definition['relationship field'];
  47     }
  48   }
  49
  50   /**
  51    * Get this field's label.
  52    */
  53   function label() {
  54     if (!isset($this->options['label'])) {
  55       return $this->ui_name();
  56     }
  57     return $this->options['label'];
  58   }
  59
  60   function option_definition() {
  61     $options = parent::option_definition();
  62
  63     $label = !empty($this->definition['label']) ? $this->definition['label'] : $this->definition['field'];
  64     $options['label'] = array('default' => $label, 'translatable' => TRUE);
  65     $options['required'] = array('default' => FALSE);
  66
  67     return $options;
  68   }
  69
  70   /**
  71    * Default options form that provides the label widget that all fields
  72    * should have.
  73    */
  74   function options_form(&$form, &$form_state) {
  75     $form['label'] = array(
  76       '#type' => 'textfield',
  77       '#title' => t('Label'),
  78       '#default_value' => isset($this->options['label']) ? $this->options['label'] : '',
  79       '#description' => t('The label for this relationship that will be displayed only administratively.'),
  80     );
  81
  82     $form['required'] = array(
  83       '#type' => 'checkbox',
  84       '#title' => t('Require this relationship'),
  85       '#description' => t('If required, items that do not contain this relationship will not appear.'),
  86       '#default_value' => !empty($this->options['required']),
  87     );
  88   }
  89
  90   /**
  91    * Called to implement a relationship in a query.
  92    */
  93   function query() {
  94     // Figure out what base table this relationship brings to the party.
  95     $table_data = views_fetch_data($this->definition['base']);
  96     $base_field = empty($this->definition['base field']) ? $table_data['table']['base']['field'] : $this->definition['base field'];
  97
  98     $this->ensure_my_table();
  99
 100     $def = $this->definition;
 101     $def['table'] = $this->definition['base'];
 102     $def['field'] = $base_field;
 103     $def['left_table'] = $this->table_alias;
 104     $def['left_field'] = $this->field;
 105     if (!empty($this->options['required'])) {
 106       $def['type'] = 'INNER';
 107     }
 108
 109     if (!empty($def['join_handler']) && class_exists($def['join_handler'])) {
 110       $join = new $def['join_handler'];
 111     }
 112     else {
 113       $join = new views_join();
 114     }
 115
 116     $join->definition = $def;
 117     $join->construct();
 118     $join->adjusted = TRUE;
 119
 120     // use a short alias for this:
 121     $alias = $def['table'] . '_' . $this->table;
 122
 123     $this->alias = $this->query->add_relationship($alias, $join, $this->definition['base'], $this->relationship);
 124   }
 125 }
 126
 127 /**
 128  * A special handler to take the place of missing or broken handlers.
 129  */
 130 class views_handler_relationship_broken extends views_handler_relationship {
 131   function ui_name($short = FALSE) {
 132     return t('Broken/missing handler');
 133   }
 134
 135   function ensure_my_table() { /* No table to ensure! */ }
 136   function query() { /* No query to run */ }
 137   function options_form(&$form, &$form_state) {
 138     $form['markup'] = array(
 139       '#prefix' => '<div class="form-item description">',
 140       '#value' => t('The handler for this item is broken or missing and cannot be used. If a module provided the handler and was disabled, re-enabling the module may restore it. Otherwise, you should probably delete this item.'),
 141     );
 142   }
 143
 144   /**
 145    * Determine if the handler is considered 'broken'
 146    */
 147   function broken() { return TRUE; }
 148 }
 149
 150 /**
 151  * @}
 152  */