readonlymode.module in Read only mode 6

Read Only Mode provides an alternate to the built in 'Maintenance Mode' in Drupal. Instead of displaying a static text file to users while the site is in maintenance mode, Read Only Mode will allow access (reading) of new content while preventing the addition of new content (posting / submitting forms / etc).

This allows the site to remain functional while maintenance is performed. This module also provides messaging to users and administrators to indicate that the site is in maintenance mode.

File

readonlymode.module

<?php

/**
 * @file
 * Read Only Mode provides an alternate to the built in 'Maintenance Mode' in
 * Drupal. Instead of displaying a static text file to users while the site is
 * in maintenance mode, Read Only Mode will allow access (reading) of new
 * content while preventing the addition of new content (posting / submitting
 * forms / etc).
 *
 * This allows the site to remain functional while maintenance is performed.
 * This module also provides messaging to users and administrators to indicate
 * that the site is in maintenance mode.
 */

/**
* Implementation of hook_perm().
* Create permission to allow access to forms while in read only mode
*/
function readonlymode_perm() {
  return array(
    'readonlymode access forms',
  );
}

/**
* Implementation of hook_form_alter().
* Permit posting of content
*/
function readonlymode_form_alter(&$form, $form_state, $form_id) {
  if (!_readonlymode_form_check($form, $form['form_id']['#value'], FALSE)) {

    // Check whether the form is a fresh form being served to the user.
    if (!isset($form_state['input']['form_token'])) {

      // If a redirect URL is set, then we redirect to it.
      if ($url = variable_get('site_readonly_url', '')) {
        drupal_goto($url);
      }
      else {

        // Remove FAPI #after_build handlers.
        $form['#after_build'] = array();

        // Remove all elements of the form.
        foreach (element_children($form) as $key) {
          if (!in_array($key, array(
            'form_id',
            'form_token',
            'form_build_id',
          ))) {
            unset($form[$key]);
          }
        }
        $form['readonly_notice'] = array(
          '#value' => _readonlymode_notice(),
          '#prefix' => '<div class="messages warning">',
          '#suffix' => '</div>',
        );
      }
    }
  }
  if (user_access('readonlymode access forms') && variable_get('site_readonly', FALSE)) {
    drupal_set_message(t('The site is currently set to read-only, content moderation is disabled for all users without the "readonlymode access forms" permission.'), 'warning', FALSE);
  }
  $form['#validate'][] = 'readonlymode_check_form_validate';
}

/**
* Implementation of hook_form_FORM_ID_alter().
* Alter the Site Maintenance form
*/
function readonlymode_form_system_site_maintenance_settings_alter(&$form, $form_state) {
  $form['read_only'] = array(
    '#title' => t('Read Only Mode'),
    '#type' => 'fieldset',
    '#weight' => 0,
    '#collapsible' => TRUE,
    '#collapsed' => variable_get('site_readonly', FALSE) ? FALSE : TRUE,
  );
  $form['read_only']['site_readonly'] = array(
    '#type' => 'checkbox',
    '#title' => t('Read only mode'),
    '#description' => t('Put the site in read-only mode. When set to "Read-only", all content moderation (add/edit) will be impossible.'),
    '#weight' => 0,
    '#default_value' => variable_get('site_readonly', FALSE),
  );

  // Message configuration is in a collapsed fieldset so that it doesn't clutter the display.
  $form['read_only']['messages'] = array(
    '#title' => t('Messages and redirects'),
    '#type' => 'fieldset',
    '#description' => t('Configure the redirect URL and messages to display to users while the site is in Read Only Mode.'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  $form['read_only']['messages']['site_readonly_message'] = array(
    '#type' => 'textarea',
    '#title' => t('Read Only Mode warning'),
    '#description' => t('This warning will be displayed when viewing a page that has a blocked form while in Read Only Mode.'),
    '#default_value' => _readonlymode_notice(),
    '#rows' => 3,
    '#required' => TRUE,
  );
  $form['read_only']['messages']['site_readonly_message_form_not_saved'] = array(
    '#type' => 'textarea',
    '#title' => t('Form submission error'),
    '#description' => t('This error will be displayed when a blocked form is submitted while in Read Only Mode. This scenario occurs when a user starts filling out a form during normal site operation and then attempts to submit the form after Read Only Mode has been enabled.'),
    '#default_value' => _readonlymode_notice_form_not_saved(),
    '#rows' => 3,
    '#required' => TRUE,
  );
  $form['read_only']['messages']['site_readonly_url'] = array(
    '#type' => 'textfield',
    '#title' => t('Redirect path'),
    '#description' => t('When given, Drupal will redirect the user to this URL when a user tries to add/edit content instead of displaying the message above.'),
    '#default_value' => variable_get('site_readonly_url', ''),
  );

  // Allowed forms configuration is in a collapsed fieldset so that it doesn't clutter the display.
  $form['read_only']['forms'] = array(
    '#title' => t('Allowed forms'),
    '#type' => 'fieldset',
    '#description' => t('Configure which forms will be exempt from restriction when in read-only mode.'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  $form['read_only']['forms']['site_readonly_forms_allowed'] = array(
    '#type' => 'textarea',
    '#title' => t('Forms that can be submitted'),
    '#description' => t("These forms are not restricted when in read only mode. Enter one form id per line. You may use the wildcard character '*' to use loose matches. For example: webform* will match all webforms. Note that the following forms will always be allowed: %allowed_forms.", array(
      '%allowed_forms' => implode(', ', _readonlymode_default_forms_allowed()),
    )),
    '#default_value' => variable_get('site_readonly_forms_allowed', ''),
  );
  $form['read_only']['forms']['site_readonly_forms_viewonly'] = array(
    '#type' => 'textarea',
    '#title' => t('Forms that can be viewed'),
    '#description' => t("These forms are allowed to be viewed but will not accept form submissions. Enter one form id per line. You may use the wildcard character '*' to use loose matches. For example: webform* will match all webforms. Note that the following forms will always be allowed: %allowed_forms.", array(
      '%allowed_forms' => implode(', ', _readonlymode_default_forms_viewonly()),
    )),
    '#default_value' => variable_get('site_readonly_forms_viewonly', ''),
  );
  $form['#validate'][] = 'readonlymode_form_validate_url';
}

/**
* Implementation of hook_form_validate().
*/
function readonlymode_form_validate_url(&$form, $form_state) {
  if ($path = $form_state['values']['site_readonly_url']) {
    $item = menu_get_item($path);
    if (!$item || !$item['access']) {
      form_set_error('site_readonly_url', t('The path %link_path is either invalid or you do not have access to it.', array(
        '%link_path' => $path,
      )));
    }
  }
}

/**
* Return the custom readonlymode warning when a page with a blocked form is viewed.
*/
function _readonlymode_notice() {
  return t(variable_get('site_readonly_message', variable_get('site_name', 'drupal') . ' is currently in maintenance. During this maintenance it is not possible to change site content (like comments, pages and users).'));
}

/**
* Return the custom readonlymode error when a user attempts to submit a blocked form.
*/
function _readonlymode_notice_form_not_saved() {
  return t(variable_get('site_readonly_message_form_not_saved', 'Data not saved. ' . variable_get('site_name', 'drupal') . ' is currently in maintenance. During maintenance it is not possible to change content. Please make a note of your changes and try again later.'));
}

/**
 * Internal handler to check whether this form is to be restricted.
 * Returns TRUE if the form is allowed, FALSE otherwise.
 */
function _readonlymode_form_check(&$form, $form_id, $submitted = TRUE) {

  // If not in read-only mode, allow the form.
  if (!variable_get('site_readonly', FALSE)) {
    return TRUE;
  }

  // Admins can access all forms.
  if (user_access('readonlymode access forms')) {
    return TRUE;
  }

  // Is the form in the list of default forms? Then allow access.
  if (in_array($form_id, _readonlymode_default_forms_allowed())) {
    return TRUE;
  }

  // Is the form in the list of read-only forms? Then allow access.
  if (!$submitted && in_array($form_id, _readonlymode_default_forms_viewonly())) {
    return TRUE;
  }

  // Check if the form is in the custom list of allowed forms. If so, allow.
  if (_readonlymode_form_list_check($form_id, variable_get('site_readonly_forms_allowed', ''))) {
    return TRUE;
  }

  // Check if the form is in the custom list of allowed read-only forms.
  if (!$submitted && _readonlymode_form_list_check($form_id, variable_get('site_readonly_forms_viewonly', ''))) {
    return TRUE;
  }
  return FALSE;
}

/**
 * Check for form_id is a given list.
 * $list is a string of form ids separated by newlines.
 * Returns TRUE is matched, FALSE otherwise.
 */
function _readonlymode_form_list_check($form_id, $list) {
  $l = preg_split('/(\\r\\n|\\n|\\r)/', $list);
  foreach ($l as $word) {

    // Skip empty words.
    if (empty($word)) {
      continue;
    }
    $word = str_replace('*', '.*', $word);
    if (preg_match('/^' . $word . '$/', $form_id) === 1) {
      return TRUE;
    }
  }
  return FALSE;
}

/**
 * Our base forms allowed during read-only mode.
 */
function _readonlymode_default_forms_allowed() {
  return array(
    'read_only',
    'user_pass',
    'user_login',
    'user_login_block',
    'search_form',
    'search_block_form',
    'system_modules',
    'system_site_maintenance_settings',
  );
}

/**
 * Our base forms allowed for view during read-only mode.
 */
function _readonlymode_default_forms_viewonly() {
  return array(
    'node_admin_content',
    'comment_admin_overview',
  );
}

/**
 * Our validate handler for checking whether the form submission is occurring while read-only mode is enabled.
 */
function readonlymode_check_form_validate($form, &$form_state) {

  // Check for read-only mode, whether we are allowed this form,
  if (!_readonlymode_form_check($form, $form['form_id']['#value'], TRUE)) {
    form_set_error('', _readonlymode_notice_form_not_saved());
  }
}

Functions

Name	Description
readonlymode_check_form_validate	Our validate handler for checking whether the form submission is occurring while read-only mode is enabled.
readonlymode_form_alter	Implementation of hook_form_alter(). Permit posting of content
readonlymode_form_system_site_maintenance_settings_alter	Implementation of hook_form_FORM_ID_alter(). Alter the Site Maintenance form
readonlymode_form_validate_url	Implementation of hook_form_validate().
readonlymode_perm	Implementation of hook_perm(). Create permission to allow access to forms while in read only mode
_readonlymode_default_forms_allowed	Our base forms allowed during read-only mode.
_readonlymode_default_forms_viewonly	Our base forms allowed for view during read-only mode.
_readonlymode_form_check	Internal handler to check whether this form is to be restricted. Returns TRUE if the form is allowed, FALSE otherwise.
_readonlymode_form_list_check	Check for form_id is a given list. $list is a string of form ids separated by newlines. Returns TRUE is matched, FALSE otherwise.
_readonlymode_notice	Return the custom readonlymode warning when a page with a blocked form is viewed.
_readonlymode_notice_form_not_saved	Return the custom readonlymode error when a user attempts to submit a blocked form.