protected function views_data_export_plugin_display_export::initialize_index in Views data export 6

Same name and namespace in other branches

1. 6.3 plugins/views_data_export_plugin_display_export.inc \views_data_export_plugin_display_export::initialize_index()
2. 6.2 plugins/views_data_export_plugin_display_export.inc \views_data_export_plugin_display_export::initialize_index()
3. 7.4 plugins/views_data_export_plugin_display_export.inc \views_data_export_plugin_display_export::initialize_index()
4. 7 plugins/views_data_export_plugin_display_export.inc \views_data_export_plugin_display_export::initialize_index()
5. 7.3 plugins/views_data_export_plugin_display_export.inc \views_data_export_plugin_display_export::initialize_index()

Called on export initialization.

Modifies the view query to insert the results into a table, which we call the 'index', this means we essentially have a snapshot of the results, which we can then take time over rendering.

This method is essentially all the best bits of the view::execute() method.

1 call to views_data_export_plugin_display_export::initialize_index()

views_data_export_plugin_display_export::execute_initial in plugins/views_data_export_plugin_display_export.inc

Initializes the whole export process and starts off the batch process.

File

plugins/views_data_export_plugin_display_export.inc, line 492

Contains the bulk export display plugin.

Class

views_data_export_plugin_display_export

The plugin that batches its rendering.

Code

protected function initialize_index() {
  $view =& $this->view;

  // Get views to build the query.
  $view
    ->build();

  // In views 2 there isn't actually an easy way to get the query that has
  // been executed, so we'll have to duplicte a lot of the code from the
  // view::execute() method.
  // Let modules modify the view just prior to executing it.
  foreach (module_implements('views_pre_execute') as $module) {
    $function = $module . '_views_pre_execute';
    $function($view);
  }

  // only rewrite the query if we have an initial query to begin with.
  if ($view->build_info['query']) {
    $query = db_rewrite_sql($view->build_info['query'], $view->base_table, $view->base_field, array(
      'view' => &$view,
    ));
    $count_query = db_rewrite_sql($view->build_info['count_query'], $view->base_table, $view->base_field, array(
      'view' => &$view,
    ));
  }
  $args = $view->build_info['query_args'];
  vpr($query);
  if ($query) {
    $replacements = module_invoke_all('views_query_substitutions', $view);
    $query = str_replace(array_keys($replacements), $replacements, $query);
    if (is_array($args)) {
      foreach ($args as $id => $arg) {
        $args[$id] = str_replace(array_keys($replacements), $replacements, $arg);
      }
    }

    // The $query is final and ready to go, we are going to redirect it to
    // become an insert into our table, sneaky!
    // Our query will look like:
    // CREATE TABLE {idx} SELECT @row := @row + 1 AS weight_alias, cl.* FROM
    // (-query-) AS cl, (SELECT @row := 0) AS r
    // We do some magic to get the row count.
    $this->batched_execution_state->sandbox['weight_field_alias'] = $this
      ->_weight_alias_create($this->view);

    // Views can construct queries that have fields with aliases longer than
    // 64 characters, which will cause problems when creating the table to
    // insert them into. So we hash the aliases down to make sure they are
    // unique.
    $this->batched_execution_state->sandbox['field_aliases'] = $this
      ->field_aliases_create($this->view);
    $select_aliases = array();
    foreach ($this->batched_execution_state->sandbox['field_aliases'] as $hash => $alias) {
      $select_aliases[] = "cl.{$alias} AS {$hash}";
    }
    $insert_query = 'CREATE TABLE {' . $this
      ->index_tablename() . '} SELECT @row := @row + 1 AS ' . $this->batched_execution_state->sandbox['weight_field_alias'] . ', ' . implode(', ', $select_aliases) . ' FROM (' . $query . ') AS cl, (SELECT @row := 0) AS r';

    // Allow for a view to query an external database.
    if (isset($view->base_database)) {
      db_set_active($view->base_database);
      $external = TRUE;
    }
    db_query($insert_query, $args);

    // Now create an index for the weight field, otherwise the queries on the
    // index will take a long time to execute.
    $ret = array();
    db_add_unique_key($ret, $this
      ->index_tablename(), $this->batched_execution_state->sandbox['weight_field_alias'], array(
      $this->batched_execution_state->sandbox['weight_field_alias'],
    ));
    if (!empty($external)) {
      db_set_active();
    }
  }
}