<?php
// $Id: page_example.module,v 1.7 2010-09-03 16:24:03 rfay Exp $

/**
 * @file
 * This is an example outlining how a module can be used to display a
 * custom page at a given URL.
 */

/**
 * Implements hook_help().
 *
 * Throughout Drupal, hook_help() is used to display help text at the top of
 * pages. Some other parts of Drupal pages get explanatory text from these hooks
 * as well. We use it here to illustrate how to add help text to the pages your
 * module defines.
 */
function page_example_help($path, $arg) {
  switch ($path) {
    case 'admin/help#simple':
      // Here is some help text for a custom page.
      return t('This sentence contains all the letters in the English alphabet.');
  }
}

/**
 * Implements hook_permission().
 *
 * Since the access to our new custom pages will be granted based on
 * special permissions, we need to define what those permissions are here.
 * This ensures that they are available to enable on the user role
 * administration pages.
 */
function page_example_permission() {
  return array(
  	'access simple page' => array(
  	  'title' => t('Access simple page'),
  	  'description' => t('Allow users to access simple page'),
    ),
    'access arguments page' => array(
      'title' => t('Access page with arguments'),
      'description' => t('Allow users to access page with arguments'),
    ),
  );
}

/**
 * Implements hook_menu().
 *
 * hook_menu() must be implemented to emit items to place in the main menu.
 * This is a required step for modules wishing to display their own pages,
 * because the process of creating the links also tells Drupal what
 * callback function to use for a given URL. The menu items returned
 * here provide this information to the menu system.
 *
 * With the below menu definitions, URLs will be interpreted as follows:
 *
 * If the user accesses http://example.com/?q=examples/page_example/simple, then
 * the menu system will first look for a menu item with that path. In this case
 * it will find a match, and execute page_example_simple().
 *
 * If the user accesses http://example.com/?q=examples/page_example/arguments,
 * no match will be found, so the system will look for 'examples/page_example',
 * which exists, and that page will be displayed.
 *
 * If the user accesses http://example.com/?q=examples/page_example/arguments,
 * the menu system will find no explicit match so will fall back to execute
 * page_example_description().
 *
 * If the user accesses
 * http://example.com/?q=examples/page_example/arguments/1/2, the menu
 * system will first look for examples/page_example/arguments/1/2. Not finding
 * a match, it will look for examples/page_example/arguments/1/%. Again not
 * finding a match, it will look for examples/page_example/arguments/%/2.
 * Yet again not finding a match, it will look for
 * examples/page_example/arguments/%/%. This time it finds a match, and so will
 * execute page_example_arguments(1, 2). Since the parameters are passed to
 * the function after the match, the function can do additional checking or
 * make use of them without resulting to the arg() function.
 *
 * The @link menu_example.module Menu Example @endlink provides extensive
 * examples for hook_menu().
 */
function page_example_menu() {

  // This is the minimum information you can provide for a menu item. This menu
  // item will be created in the default menu.
  $items['examples/page_example'] = array(
    'title' => 'Page Example',
    'page callback' => 'page_example_description',
    'access callback' => TRUE,
    'expanded' => TRUE,
  );

  $items['examples/page_example/simple'] = array(
    'title' => 'Simple - no arguments',
    'page callback' => 'page_example_simple',
    'access arguments' => array('access simple page'),
  );

  // By using the MENU_CALLBACK type, we can register the callback for this
  // path but do not have the item show up in the menu; the admin is not allowed
  // to enable the item in the menu, either.
  //
  // Notice that the 'page arguments' is an array of numbers. These will be
  // replaced with the corresponding parts of the menu path. In this case a 0
  // would be replaced by 'example', a 1 by 'arguments', and like wise 2 and 3 will
  // be replaced by what ever the user provides. These will be passed as
  // arguments to the page_example_arguments() function.
  $items['examples/page_example/arguments/%/%'] = array(
    'page callback' => 'page_example_arguments',
    'page arguments' => array(3, 4),
    'access arguments' => array('access arguments page'),
    'type' => MENU_CALLBACK,
  );

  return $items;
}

function page_example_description() {
  return array('#markup' => t('The page_example provides two pages, "simple" and "arguments". The <a href="@simple_link">simple page</a> just returns a renderable array for display. The <a href="@arguments_link">arguments page</a> takes two arguments and displays them, as in @arguments_link', array('@simple_link' => url('examples/page_example/simple', array('absolute' => TRUE)), '@arguments_link' => url('examples/page_example/arguments/23/56', array('absolute' => TRUE)))));
}
/**
 * A simple page callback.
 *
 * Page callbacks return a renderable array with the content area of the page.
 * The theme system will later render and surround the content in the
 * appropriate blocks, navigation, and styling.
 *
 * If you do not want to use the theme system (for example for outputting an
 * image or XML), you should print the content yourself and not return anything.
 */
function page_example_simple() {
  return array('#markup' => '<p>' . t('Simple page: The quick brown fox jumps over the lazy dog.') . '</p>');
}

/**
 * A more complex page callback that takes arguments.
 *
 * The arguments are passed in from the page URL. The in our hook_menu
 * implementation we instructed the menu system to extract the last two
 * parameters of the path and pass them to this function as arguments.
 *
 * This function also demonstrates a more complex render array in the returned
 * values. Instead of just rendering the HTML with a theme('item_list'), the
 * list is left unrendered, and a #theme attached to it so that it can be
 * rendered as late as possible, giving more parts of the system a chance to
 * change it if necessary.
 */
function page_example_arguments($first, $second) {
  // Make sure you don't trust the URL to be safe! Always check for exploits.
  if (!is_numeric($first) || !is_numeric($second)) {
    // We will just show a standard "access denied" page in this case.
    drupal_access_denied();
    return;  // We actually don't get here.
  }

  $list[] = t("First number was @number.", array('@number' => $first));
  $list[] = t("Second number was @number.", array('@number' => $second));
  $list[] = t('The total was @number.', array('@number' => $first + $second));

  $render_array['page_example_arguments'] = array(
    '#theme' => 'item_list',  // The theme function to apply to the #items
    '#items' => $list,  // The list itself.
    '#title' => t('Argument Information'),
  );
  return $render_array;
}