<?php
// $Id: ajax.inc,v 1.5 2009-03-24 18:32:44 merlinofchaos Exp $

/**
 * @file
 * Utilize the CTools AJAX responder.
 *
 * The AJAX responder is a javascript tool to make it very easy to do complicated
 * operations as a response to AJAX requests. When links are attached to the ajax
 * responder, the server sends back a packet of JSON data; this packet is an
 * array of commands to carry out.
 *
 * The command names correlate to functions in the responder space, making it
 * relatively easy for applications to provide their own commands to do whatever
 * spiffy functionality is necessary.
 *
 * Each command is an object. $object->command is the type of command and
 * will be used to find the function (it will correllate directly to
 * a function in the Drupal.CTools.AJAX.Command space). The object can
 * contain any other data that the command needs to process.
 *
 * Built in commands include:
 * - replace
 *   - selector: The CSS selector. This can be any selector jquery uses in $().
 *   - data: The data to use with the jquery replace() function.
 *
 * - prepend
 *   - selector: The CSS selector. This can be any selector jquery uses in $().
 *   - data: The data to use with the jquery prepend() function.
 *
 * - append
 *   - selector: The CSS selector. This can be any selector jquery uses in $().
 *   - data: The data to use with the jquery append() function.
 *
 * - after
 *   - selector: The CSS selector. This can be any selector jquery uses in $().
 *   - data: The data to use with the jquery after() function.
 *
 * - before
 *   - selector: The CSS selector. This can be any selector jquery uses in $().
 *   - data: The data to use with the jquery before() function.
 *
 * - remove
 *   - selector: The CSS selector. This can be any selector jquery uses in $().
 *
 * - changed
 *   - selector: The CSS selector. This selector will have 'changed' added as a clas.
 *   - star: If set, will add a star to this selector. It must be within the 'selector' above.
 *
 * - alert
 *   - title: The title of the alert.
 *   - data: The data in the alert.
 *
 * - css
 *   - selector: The CSS selector to add CSS to.
 *   - argument: An array of 'key': 'value' CSS selectors to set.
 *
 * Commands are usually created with a couple of helper functions, so they
 * look like this:
 *
 * @code
 *   $commands = array();
 *   $commands[] = ctools_ajax_command_replace('#ctools-object-1', 'some html here');
 *   $commands[] = ctools_ajax_command_changed('#ctools-object-1');
 *   ctools_ajax_render($commands); // this function exits.
 * @endcode
 */

/**
 * Render an image as a button link. This will automatically apply an AJAX class
 * to the link and add the appropriate javascript to make this happen.
 *
 * @param $image
 *   The path to an image to use that will be sent to theme('image') for rendering.
 * @param $dest
 *   The destination of the link.
 * @param $alt
 *   The alt text of the link.
 * @param $class
 *   Any class to apply to the link. @todo this should be a options array.
 */
function ctools_ajax_image_button($image, $dest, $alt, $class = '') {
  return ctools_ajax_text_button(theme('image', $image), $dest, $alt, $class);
}

/**
 * Render text as a link. This will automatically apply an AJAX class
 * to the link and add the appropriate javascript to make this happen.
 *
 * Note: 'html' => true so be sure any text is vetted! Chances are these kinds of buttons will
 * not use user input so this is a very minor concern.
 *
 * @param $image
 *   The path to an image to use that will be sent to theme('image') for rendering.
 * @param $dest
 *   The destination of the link.
 * @param $alt
 *   The alt text of the link.
 * @param $class
 *   Any class to apply to the link. @todo this should be a options array.
 * @param $type
 *   A type to use, in case a different behavior should be attached. Defaults
 *   to ctools-use-ajax.
 */
function ctools_ajax_text_button($text, $dest, $alt, $class = '', $type = 'ctools-use-ajax') {
  return l($text, $dest, array('html' => TRUE, 'attributes' => array('class' => "$type $class", 'title' => $alt, 'alt' => $alt)));
}

/**
 * Create a command array for the error case.
 */
function ctools_ajax_command_error($error = '') {
  return array(
    'command' => 'alert',
    'title' => t('Error'),
    'text' => $error ? $error : t('Server reports invalid input error.'),
  );
}

/**
 * Create a replace command for the AJAX responder.
 *
 * The replace command will replace a portion of the current document
 * with the specified HTML.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $html
 *   The data to use with the jquery replace() function.
 */
function ctools_ajax_command_replace($selector, $html) {
  return array(
    'command' => 'replace',
    'selector' => $selector,
    'data' => $html,
  );
}

/**
 * Set the HTML of a given selector to the given data.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $html
 *   The data to use with the jquery replace() function.
 */
function ctools_ajax_command_html($selector, $html) {
  return array(
    'command' => 'html',
    'selector' => $selector,
    'data' => $html,
  );
}

/**
 * Create a prepend command for the AJAX responder.
 *
 * This will prepend the HTML to the specified selector.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $html
 *   The data to use with the jquery prepend() function.
 */
function ctools_ajax_command_prepend($selector, $html) {
  return array(
    'command' => 'prepend',
    'selector' => $selector,
    'data' => $html,
  );
}

/**
 * Create an append command for the AJAX responder.
 *
 * This will append the HTML to the specified selector.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $html
 *   The data to use with the jquery append() function.
 */
function ctools_ajax_command_append($selector, $html) {
  return array(
    'command' => 'append',
    'selector' => $selector,
    'data' => $html,
  );
}

/**
 * Create an after command for the AJAX responder.
 *
 * This will add the HTML after the specified selector.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $html
 *   The data to use with the jquery after() function.
 */
function ctools_ajax_command_after($selector, $html) {
  return array(
    'command' => 'after',
    'selector' => $selector,
    'data' => $html,
  );
}

/**
 * Create a before command for the AJAX responder.
 *
 * This will add the HTML before the specified selector.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $html
 *   The data to use with the jquery before() function.
 */
function ctools_ajax_command_before($selector, $html) {
  return array(
    'command' => 'before',
    'selector' => $selector,
    'data' => $html,
  );
}

/**
 * Create a remove command for the AJAX responder.
 *
 * This will remove the specified selector and everything within it.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 */
function ctools_ajax_command_remove($selector) {
  return array(
    'command' => 'remove',
    'selector' => $selector,
  );
}

/**
 * Create a changed command for the AJAX responder.
 *
 * This will mark an item as 'changed'.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $star
 *   An optional CSS selector which must be inside $selector. If specified,
 *   a star will be appended.
 */
function ctools_ajax_command_changed($selector, $star = '') {
  return array(
    'command' => 'changed',
    'selector' => $selector,
    'star' => $star,
  );
}

/**
 * Create a changed command for the AJAX responder.
 *
 * This will mark an item as 'changed'.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 * @param $argument
 *   An array of key: value pairs to set in the CSS for the selector.
 */
function ctools_ajax_command_css($selector, $argument) {
  return array(
    'command' => 'css',
    'selector' => $selector,
    'argument' => $argument,
  );
}

/**
 * Force a table to be restriped.
 *
 * This is usually used after a table has been modifed by a replace or append
 * command.
 *
 * @param $selector
 *   The CSS selector. This can be any selector jquery uses in $().
 */
function ctools_ajax_command_restripe($selector) {
  return array(
    'command' => 'restripe',
    'selector' => $selector,
  );
}

/**
 * Render a commands array into JSON and immediately hand this back
 * to the AJAX requester.
 */
function ctools_ajax_render($commands = array()) {
  drupal_json($commands);
  exit;
}

/**
 * Send an error response back via AJAX and immediately exit.
 */
function ctools_ajax_render_error($error = '') {
  $commands = array();
  $commands[] = ctools_ajax_command_error($error);
  ctools_ajax_render($commands);
}