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   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 will 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 relationship 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   */