Drupal views contextual filter: use last argument as filter value

Question

I would like a views contextual filter to only use the last argument in the url. Given the following taxonomy structure, I would want /term-a to return Term A1 and Term A2 only (which works fine). However, if the url is /term-a/term-a1 I would want only Term A1a to be returned, which isn't working, it's still returning Term A1 and Term A2

Within views, I don't see a way to use the last part of the path for the filter. I tried to remove the argument from the path and then use the following as a default argument:

$path = arg();
return array_pop($path);

Here is the sample term hierarchy:

- Term A
  - Term A1
    - Term A1a
  - Term A2
- Term B
  - Term B1
  - Term B2

Just to reiterate what is returned:

The path /term-a returns:

• Term A1
• Term A2

The path term-a/term-a1 returns:

• Term A1
• Term A2

The path /term-a1 returns:

• Term A1a

Answer 1

One solution would be hook_views_pre_view()

function MYMODULE_views_pre_view(&$view, &$display_id, &$args) {
    if ($view->name == 'view_machine_name' && $display_id == 'my_display_id') {
        $args = array(end($args));
    }
}

For a view with one contextual filter this would always set the argument to the last argument from the URL.

Answer 2

Use one view with two page displays.

The first display will take one contextual filter of /term-a

The second display will take two contextual filters. The first filter will be global null (so you can throw it away), and the second will be term-a1