Making a block example done live at WesternMassDrupalCamp 2011

The most fun lesson learned– passing in a pure integer to the $block['content'] in the implementation of hook_block_view causes an unsupported operand error so deep in the block rendering system the stack trace doesn't even know where it came from.

<?php
/**
 * Implements hook_block_info().
 */
function dgd7glue_block_info() {
  $blocks = array();
  $blocks['twoplustwo'] = array(
    'info' => t('Two plus two.'),
  );
  return $blocks;
}

/**
 * Implements hook_block_view().
 */
function dgd7glue_block_view($delta = '') {
  $block = array();
  switch ($delta) {
    case 'twoplustwo':
      $block['subject'] = t('Two plus two equals');
      $result = 2 + 2;
      $content = t('This is a string of the number ') . $result;
      $build = array();
      $build['main_content'] = array(
        '#markup' => $content,
        '#weight' => 15,
      );
      $build['morehere'] = array(
        '#type' => 'link',
        '#title' => t('Exit block region demonstration'),
        '#href' => 'admin/structure/block',
        '#options' => array('attributes' => array('class' => array('block-demo-backlink', 'overlay-restore'))),
        '#weight' => -10,
      );
      $block['content'] = $build;
      break;
  }
  return $block;
}
?>