Drupal 6 template - Better suggestion for change image path in preprocess?

Question

I have to change the template in one of Drupal 6 project.

On every "page" node type is stored an image in the CCK field. I have made new design template to change the the design through CSS. But now the customer demand is to change the images that are in CCK field named "field_obr" (one per node) only in my new design template. That he can switch the themes and the images will correspond with themes (current design = original images from CCK, new design = images from altered path from original CCK field path). Images names can be the same, only the directory changed.

Original images are stored in folder like:

sites/default/files/image1.jpg
sites/default/files/image2.jpg
...

I want to change in my new theme the path to an image to:

sites/default/files/new_img/image1.jpg
sites/default/files/new_img/image2.jpg
...

= to add the "/new_img" folder in the path before the image. (Or later path to my template file - thac I know how to, but I'm looking here for the principle.)

Template outputs the image as:

 <img  class="imagefield imagefield-field_obr" width="229" height="346" alt="" src="/sites/default/files/radek_home_0.jpg?1354577633" /> 

I have fond this solutions:

First solution - change $content output through preg_replace()

In the "node-page.tpl.php" to look in the $content throug preg_replace() function, find the path and change/add the string as I wish. - This is doable, but i feel that is not optimal solution to Drupal-flow.

Second solution - using hook_page_alter() or hook_page_build() functions

I have fount that the content of variables can be altered through using hook_page_alter() and hook_page_build() functions.

I put these functions to my "template.php" before phptemplate_preprocess_page(&$vars) function, bud it seems that they do nothing:

function hook_page_build(&$page) {
//    print_r($page);
    $page['node']->field_obr['0']['filepath'] = "sites/default/files/new_img/radek_home_0.jpg";
    echo "Test function hook_page_build() has run";
}

Than i found in the docu, that these functions are for Drupal 7+ :-(

Question: Can anyone explain me the best solution tho solve the situation described in the beginning? How to achieve it through the profi "Drupal way?" Thank you. Frantisek

Answer 1

I have made some research and for Drupal 6 found single easy working solution for the described problem. It is the mentioned PHP preg_replace() function located in the template page.tpl.php:

print preg_replace('#/sites/default/files/#', '/sites/default/files/_new/', $content);