1 files changed, 142 insertions, 0 deletions
diff --git a/sites/all/modules/views/handlers/views_handler_filter_fields_compare.inc b/sites/all/modules/views/handlers/views_handler_filter_fields_compare.inc
new file mode 100644
index 000000000..fe94ce767
--- /dev/null
+++ b/sites/all/modules/views/handlers/views_handler_filter_fields_compare.inc
@@ -0,0 +1,142 @@
+<?php
+
+/**
+ * @file
+ * Definition of views_handler_filter_fields_compare.
+ */
+
+/**
+ * A handler to filter a view using fields comparison.
+ *
+ * @ingroup views_filter_handlers
+ */
+
+class views_handler_filter_fields_compare extends views_handler_filter {
+
+  function can_expose() {
+    return FALSE;
+  }
+
+  /**
+   * Overrides views_handler_filter#option_definition().
+   */
+  function option_definition() {
+    $options = parent::option_definition();
+
+    $options['left_field'] = $options['right_field'] = array('default' => '');
+
+    return $options;
+  }
+
+  /**
+   * Provide a list of all operators.
+   */
+  function fields_operator_options() {
+    return array(
+      '<' => t('Is less than'),
+      '<=' => t('Is less than or equal to'),
+      '=' => t('Is equal to'),
+      '<>' =>  t('Is not equal to'),
+      '>=' => t('Is greater than or equal to'),
+      '>' => t('Is greater than')
+    );
+  }
+
+  /**
+   * Provide a list of available fields.
+   */
+  function field_options() {
+    $options = array();
+
+    $field_handlers = $this->view->display_handler->get_handlers('field');
+    foreach ($field_handlers as $field => $handler) {
+      if ($handler->table != 'views') {
+        $options[$field] = $handler->ui_name();
+      }
+    }
+
+    return $options;
+  }
+
+  /**
+   * Overrides views_handler_filter#options_form().
+   */
+  function options_form(&$form, &$form_state) {
+    parent::options_form($form, $form_state);
+
+    $field_options = $this->field_options();
+
+    $form['left_field'] = array(
+      '#type' => 'select',
+      '#title' => t('Left field'),
+      '#default_value' => $this->options['left_field'],
+      '#options' => $field_options,
+      '#weight' => -3,
+    );
+
+    $form['operator'] = array(
+      '#type' => 'select',
+      '#title' => t('Operator'),
+      '#default_value' => $this->options['operator'],
+      '#options' => $this->fields_operator_options(),
+      '#weight' => -2,
+    );
+
+    $form['right_field'] = array(
+      '#type' => 'select',
+      '#title' => t('Right field'),
+      '#default_value' => $this->options['right_field'],
+      '#options' => $field_options,
+      '#weight' => -1,
+    );
+
+  }
+
+  /**
+   * Overrides views_handler_filter#query().
+   *
+   * Build extra condition from existing fields (from existing joins).
+   */
+  function query() {
+    $left = $this->options['left_field'];
+    $right = $this->options['right_field'];
+
+    // Get all existing field handlers.
+    $field_handlers = $this->view->display_handler->get_handlers('field');
+
+    // Make sure the selected fields still exist.
+    if (!isset($field_handlers[$left], $field_handlers[$right])) {
+      return;
+    }
+
+    // Get the left table and field.
+    $left_handler = $field_handlers[$left];
+    $left_handler->set_relationship();
+    $left_table_alias = $this->query->ensure_table($left_handler->table, $left_handler->relationship);
+
+    // Get the left table and field.
+    $right_handler = $field_handlers[$right];
+    $right_handler->set_relationship();
+    $right_table_alias = $this->query->ensure_table($right_handler->table, $right_handler->relationship);
+
+    // Build piece of SQL.
+    $snippet =
+      $left_table_alias . '.' . $left_handler->real_field .
+      ' ' . $this->options['operator'] . ' ' .
+      $right_table_alias . '.' . $right_handler->real_field;
+
+    $this->query->add_where_expression($this->options['group'], $snippet);
+  }
+
+  /**
+   * Overrides views_handler_filter#admin_summary().
+   */
+  function admin_summary() {
+    return check_plain(
+      $this->options['left_field'] . ' ' .
+      $this->options['operator'] . ' ' .
+      $this->options['right_field']
+    );
+  }
+
+}