dmometasettings.php

<?php
class dmometasettings
{
    public $file;
    public $plugin;
    public $settings;
    public $namespace;

    public function __construct($file, $namespace)
    {
        $this->file = $file;
        $this->plugin = plugin_basename($file);
        $this->namespace = $namespace;

        $this->settings = (object)[];

        $this->set_defaults();
    }

    /**
    * Set default options settings for plugin
    */
    public function set_defaults()
    {
        if (!get_option('dxw_members_only_list_content')) {
            add_option('dxw_members_only_list_content', '');
        }

        if (!get_option('dxw_members_only_redirect')) {
            add_option('dxw_members_only_redirect', '/wp-login.php?redirect_to=%return_path%');
        }

        if (!get_option('dxw_members_only_redirect_root')) {
            add_option('dxw_members_only_redirect_root', '/wp-login.php?redirect_to=%return_path%');
        }

        if (!get_option('dxw_members_only_max_age')) {
            add_option('dxw_members_only_max_age', 0);
        }

        if (!get_option('dxw_members_only_max_age_static')) {
            add_option('dxw_members_only_max_age_static', 0);
        }

        if (!get_option('dxw_members_only_max_age_public')) {
            add_option('dxw_members_only_max_age_public', 86400);
        }
    }

    /**
    * Wrapper for adding settings with the WP Settings API
    *
    * @param string $title    Name of the setting
    * @param array  $options  Setting options array
    * @param string $callback Callback function
    */
    public function add_settings($title, $options, $callback)
    {
        $this->settings->title = $title;
        $this->settings->options = $options;
        $this->settings->callback = $callback;

        add_filter('plugin_action_links', [$this, 'plugin_action_links'], 10, 2);
        add_action('admin_menu', [$this, 'admin_menu']);
        add_filter('whitelist_options', [$this, 'whitelist_options']);
    }

    /**
    * Insert action links for plugin
    *
    * @param  array  $links Existing action links for the plugin
    * @param  string $file  File to link to in the actions
    * @return array         New action links
    */
    public function plugin_action_links($links, $file)
    {
        if (dirname($file) === dirname($this->plugin)) {
            array_unshift($links, '<a href="'.get_admin_url(null, 'options-general.php?page='.$this->plugin).'">'.__('Settings', 'dxwmembersonly').'</a>');
        }
        return $links;
    }

    /**
    * Create admin menu for plugin
    *
    * @return void
    */
    public function admin_menu()
    {
        add_options_page($this->settings->title, $this->settings->title, 'edit_users', $this->file, $this->settings->callback);
    }

    /**
    * Prefix options with namespace
    *
    * @param  array  $whitelist_options Options to whitelist
    * @return array                     Whitelisted options
    */
    public function whitelist_options($whitelist_options)
    {
        $whitelist_options[$this->namespace] = [];
        foreach ($this->settings->options as $opt) {
            $whitelist_options[$this->namespace][] = $this->namespace.'_'.$opt;
        }
        return $whitelist_options;
    }
}