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   1  <?php
   2  // $Id: views_handler_relationship.inc,v 1.4.2.1 2009/11/02 23:25:14 merlinofchaos Exp $
   3  /**
   4   * @file
   5   * Views' relationship handlers.
   6   */
   7  
   8  /**
   9   * @defgroup views_relationship_handlers Views' relationship handlers
  10   * @{
  11   * Handlers to tell Views how to create alternate relationships.
  12   */
  13  
  14  /**
  15   * Simple relationship handler that allows a new version of the primary table
  16   * to be linked in.
  17   *
  18   * The base relationship handler can only handle a single join. Some relationships
  19   * are more complex and might require chains of joins; for those, you must
  20   * utilize a custom relationship handler.
  21   *
  22   * Definition items:
  23   * - base: The new base table this relationship will be adding. This does not
  24   *   have to be a declared base table, but if there are no tables that
  25   *   utilize this base table, it won't be very effective.
  26   * - base field: The field to use in the relationship; if left out this will be
  27   *   assumed to be the primary field.
  28   * - relationship table: The actual table this relationship operates against.
  29   *   This is analogous to using a 'table' override.
  30   * - relationship field: The actual field this relationship operates against.
  31   *   This is analogous to using a 'real field' override.
  32   * - label: The default label to provide for this relationship, which is
  33   *   shown in parentheses next to any field/sort/filter/argument that uses
  34   *   the relationship.
  35   */
  36  class views_handler_relationship extends views_handler {
  37    /**
  38     * Init handler to let relationships live on tables other than
  39     * the table they operate on.
  40     */
  41    function init(&$view, $options) {
  42      parent::init($view, $options);
  43      if (isset($this->definition['relationship table'])) {
  44        $this->table = $this->definition['relationship table'];
  45      }
  46      if (isset($this->definition['relationship field'])) {
  47        $this->field = $this->definition['relationship field'];
  48      }
  49    }
  50  
  51    /**
  52     * Get this field's label.
  53     */
  54    function label() {
  55      if (!isset($this->options['label'])) {
  56        return $this->ui_name();
  57      }
  58      return $this->options['label'];
  59    }
  60  
  61    function option_definition() {
  62      $options = parent::option_definition();
  63  
  64      $label = !empty($this->definition['label']) ? $this->definition['label'] : $this->definition['field'];
  65      $options['label'] = array('default' => $label, 'translatable' => TRUE);
  66      $options['required'] = array('default' => FALSE);
  67  
  68      return $options;
  69    }
  70  
  71    /**
  72     * Default options form that provides the label widget that all fields
  73     * should have.
  74     */
  75    function options_form(&$form, &$form_state) {
  76      $form['label'] = array(
  77        '#type' => 'textfield',
  78        '#title' => t('Label'),
  79        '#default_value' => isset($this->options['label']) ? $this->options['label'] : '',
  80        '#description' => t('The label for this relationship that will be displayed only administratively.'),
  81      );
  82  
  83      $form['required'] = array(
  84        '#type' => 'checkbox',
  85        '#title' => t('Require this relationship'),
  86        '#description' => t('If required, items that do not contain this relationship will not appear.'),
  87        '#default_value' => !empty($this->options['required']),
  88      );
  89    }
  90  
  91    /**
  92     * Called to implement a relationship in a query.
  93     */
  94    function query() {
  95      // Figure out what base table this relationship brings to the party.
  96      $table_data = views_fetch_data($this->definition['base']);
  97      $base_field = empty($this->definition['base field']) ? $table_data['table']['base']['field'] : $this->definition['base field'];
  98  
  99      $this->ensure_my_table();
 100  
 101      $def = $this->definition;
 102      $def['table'] = $this->definition['base'];
 103      $def['field'] = $base_field;
 104      $def['left_table'] = $this->table_alias;
 105      $def['left_field'] = $this->field;
 106      if (!empty($this->options['required'])) {
 107        $def['type'] = 'INNER';
 108      }
 109  
 110      if (!empty($def['join_handler']) && class_exists($def['join_handler'])) {
 111        $join = new $def['join_handler'];
 112      }
 113      else {
 114        $join = new views_join();
 115      }
 116  
 117      $join->definition = $def;
 118      $join->construct();
 119      $join->adjusted = TRUE;
 120  
 121      // use a short alias for this:
 122      $alias = $def['table'] . '_' . $this->table;
 123  
 124      $this->alias = $this->query->add_relationship($alias, $join, $this->definition['base'], $this->relationship);
 125    }
 126  }
 127  
 128  /**
 129   * A special handler to take the place of missing or broken handlers.
 130   */
 131  class views_handler_relationship_broken extends views_handler_relationship {
 132    function ui_name($short = FALSE) {
 133      return t('Broken/missing handler');
 134    }
 135  
 136    function ensure_my_table() { /* No table to ensure! */ }
 137    function query() { /* No query to run */ }
 138    function options_form(&$form, &$form_state) {
 139      $form['markup'] = array(
 140        '#prefix' => '<div class="form-item description">',
 141        '#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.'),
 142      );
 143    }
 144  
 145    /**
 146     * Determine if the handler is considered 'broken'
 147     */
 148    function broken() { return TRUE; }
 149  }
 150  
 151  /**
 152   * @}
 153   */