Enable bean blocks to be themed (using a .tpl file) according to bean-type: i.e. block__bean__BEAN-TYPE.tpl

Theme Bean Block & Display Suite Combo.php

Enable bean blocks to be themed (using a .tpl file) according to bean-type: 
i.e. block__bean__BEAN-TYPE.tpl

Why? Combine a Bean Block with Display Suite and the innards of the block will match the DS layout 
used, however the outer wrapping of the block must be themed separately.  However if you write a 
.tpl that matches the block it will take precedence and the DS layout will be lost.  This prevents 
using a DS layout for each type of Bean while simultaneously having full control over the Bean 
Block’s mark-up. 

This solution adds a theme hook suggestion so that .tpl files may be written for each type of Bean.

Add this function to template.php
<?php

/**
 * Implements template_preprocess_block
 *
 * enable bean blocks to be themed by bean-type:
 * i.e. block__bean__BEAN-TYPE.tpl
 */
function THEMENAME_preprocess_block(&$variables) {

  $block = $variables['block'];
  $block_module = $block->module;
  $elements = $variables['elements'];

  // Add Bean Type to Theme Hook Suggestions
  // enable bean blocks to be themed by bean-type: i.e. block__bean__BEAN-TYPE.tpl

  // select Bean Blocks and ignore other Blocks
  if (!empty($block_module) && ($block_module == 'bean')) {

    // the location of the Bean array within $variables is a moving target
    // e.g. use of the Context Module will change it's location to within $elements['content']
    // try the likely locations first before recursively iterating through $elements
    if (array_key_exists('bean', $elements)) {
      $bean_array = $elements['bean'];
    } else if (array_key_exists('bean', $elements['content'])) {
      $bean_array = $elements['content']['bean'];
    } else {
      $bean_array = array_find_first_value('bean', $elements);
    }
    
    // test that the Bean array has been found
    if ($bean_array) {
      $mystery_key_array = element_children($bean_array);

      if ($mystery_key_array) {
        $bean = $bean_array[$mystery_key_array[0]];

        if (!empty($bean['#bundle'])) {
          $variables['theme_hook_suggestions'][] = 'block__' . $block_module . '__' . $bean['#bundle'];
        }
      }
    }
  }

}



/*  C U S T O M   F U N C T I O N S  */

/*
 * search an array recursively to find
 * the first instance of a key and return its value
 *
 * useful when you do not know the location of a key nested (only once) in a multidimensional array
 *
 */
function array_find_first_value($needle_key, array $haystack) {
  if (array_key_exists($needle_key, $haystack)) {
    return $haystack[$needle_key];
  }
  foreach ($haystack as $key => $value) {
    if (is_array($value)) {
      $result = array_find_first_value($needle_key, $value);
      if ($result) {
        return $result;
      }
    }
  }
  return false;
}

15 April 2013 updated to play nicely with Context module.

2 August 2013 removed test for Context Module for more versatility, and increased use of array_key_exists to avoid asking for keys that don't exist

added use of array_find_first_value() in case the location of the Bean array varies more than I know