simplyFavicon/_admin.php

<?php
/**
 * @brief simplyFavicon, a plugin for Dotclear 2
 *
 * @package Dotclear
 * @subpackage Plugin
 *
 * @author Jean-Christian Denis
 *
 * @copyright Jean-Christian Denis
 * @copyright GPL-2.0 https://www.gnu.org/licenses/gpl-2.0.html
 */
if (!defined('DC_CONTEXT_ADMIN')) {
    return;
}

dcCore::app()->addBehavior('adminBlogPreferencesFormV2', ['adminSimplyFavicon', 'adminBlogPreferencesForm']);
dcCore::app()->addBehavior('adminBeforeBlogSettingsUpdate', ['adminSimplyFavicon', 'adminBeforeBlogSettingsUpdate']);

class adminSimplyFavicon
{
    public static $extensions = ['ico', 'png', 'bmp', 'gif', 'jpg', 'mng'];

    public static function adminBlogPreferencesForm($blog_settings)
    {
        $exists = [];
        $path   = path::fullFromRoot((string) $blog_settings->system->public_path, DC_ROOT);
        foreach (self::$extensions as $ext) {
            if (file_exists($path . '/favicon.' . $ext)) {
                $exists[] = sprintf('<li title="%s">%s</li>', $path . '/favicon.' . $ext, 'favicon.' . $ext);
            }
        }

        echo
        '<div class="fieldset clear"><h4 id="simply_favicon_params">Favicon</h4>' .
        '<div class="two-cols"><div class="col">' .
        '<p><label class="classic">' .
        form::checkbox('simply_favicon', '1', (bool) $blog_settings->system->simply_favicon) .
        __('Enable "Simply favicon" extension') . '</label></p>' .
        '<p class="form-note">' .
        __("You must place an image called favicon.png or .jpg or .ico into your blog's public directory.") .
        '</p></div><div class="col">' .
        (
            empty($exists) ?
            '<p>' . __('There are no favicon in blog public directory') . '</p>' :
            '<p>' . __('Current favicons:') . '</p><ul class="nice">' . implode($exists) . '</ul>'
        ) .
        '</div></div><br class="clear" /></div>';
    }

    public static function adminBeforeBlogSettingsUpdate($blog_settings)
    {
        $blog_settings->system->put('simply_favicon', !empty($_POST['simply_favicon']));
    }
}