Creating a redirect for content type conditionally

Question

I'm new to Drupal and have inherited a fully functional system (Drupal 7.43), I've had a look on Google with no joy, so hopefully you can help.

For a specific content type it has the following fields (simplified)

URL info1 info2

When the user clicks to read the page if info1 is empty I would like to redirect to the URL (which is an external, absolute URL) if there is content in info1 I would like to show the page as normal.

How would I go about doing this?

Answer 1

No problem bro, its pretty simple. I'll write you a step by step tutorial as an edit. Standby.

You will need to create a preprocess function. Add a folder and a file in your theme. THEMENAME/preprocess/node.preprocess.inc with this code:

<?php

/**
 * Implements hook_preprocess_node().
 *
 * Hyjacking the nodes normal node link if an external link is specified
 *
 */
function YOURTHEMENAME_preprocess_node(&$variables) {

  $url = NULL;

  switch ($variables['type']) {
    case 'article':
      if (isset($variables['alternate_link']['und'][0]['url'])) {
        $url = (!empty($variables['alternate_link']['und'][0]['url'])) ? $variables['alternate_link']['und'][0]['url'] : NULL;
        $variables['node_url'] = $url;
      }
    break;
  }

}

My example states that In the case of a Content Type with the machine name of 'article' (yours may be different) do something.

THEN check if my field with the machine name of 'alternative_link' (your machine name will be different) has a value then do something.

It will then use the node's default $url variable.

If it is not set, it will ignore this code and leave your $url clean