将变量传递给_preprocess_node函数以在节点模板中使用

I've been racking my brains over this one but I'll do my best to describe the problem as best as possible. I have a custom function written within template.php, with a bunch of conditionals. When a condition is true, I would like to assign a value to a variable, and then pass that variable intro a node preprocess function that allows that variables to be rendered on a node template.

The function containing the condition:

function _mytheme_date_repeat_string($vars) {

    $exdate_pos = strpos($rrule['WKST'], 'EXDATE:');
    if($exdate_pos > 0) {

        $vars['testvar'] = 'abc123';
    }
 }

The preprocess function that I would like to render the variable in for node template use:

function mytheme_preprocess_node(&$vars, $hook) {

  $vars['new_variable'] = $testvar;

}

Intended usage in node.tpl.php:

<?php print $new_variable; ?>

I'm not great with PHP, but I know enough about programming to know that variable scope might be an issue here. What would be the best way to implement this? Any guidance is greatly appreciated.

Thanks, Mark.

If it is not called, your _mytheme_date_repeat_string() function will never be executed. Preprocess functions (ie. any function starting mytheme_preprocess_, are called automatically by Drupal's theme system.

What you need is either move the code of _mytheme_date_repeat_string() in mytheme_preprocess_node() or refactor it and call it.

function _mytheme_date_repeat_string($rrule) {
    $exdate_pos = strpos($rrule['WKST'], 'EXDATE:');
    if($exdate_pos > 0) {
      return 'abc123';
    }
    else {
      return NULL;
    }
 }

/**
 * Prepares variables for node templates.
 */
function mytheme_preprocess_node(&$variables, $hook) {

  // Get $rrule from somewhere
  $rrule = ... ;

  $testvar = _mytheme_date_repeat_string($rrule);
  if ($testvar) {
    $variables['new_variable'] = $testvar;
  }
}

You code does not show where the $rrule calue comes from. I assume you would get it for $variables['node'].