At work we're developing a new WordPress theme. The theme "depends" on a few plugins. We are adding the plugins using the TGM Plugin Activation library.

Our implementation is using most of the example.php code, but I decided to store the plugin data in a json file:

[
    {
        "name": "Advanced Custom Fields",
        "slug": "advanced-custom-fields",
        "required": true,
        "force_activation": true,
        "force_deactivation": true
    },
    {
        "name": "Simple Comment Editing",
        "slug": "simple-comment-editing",
        "required": true,
        "force_activation": true,
        "force_deactivation": true
    }
]

I'm loading the json file using the following code:

$current_theme = wp_get_theme();
$plugins_data_file = dirname( __FILE__ ) . '/plugins/plugins.json';

if (file_exists($plugins_data_file)) {

    $plugins_data = file_get_contents($plugins_data_file);
    $plugins = json_decode($plugins_data,true);

    if ($plugins === null && json_last_error() !== JSON_ERROR_NONE) {
        $errormsg = json_last_error_msg();
         return add_action( 'admin_notices', function() use ( $plugins_data_file, $errormsg,  $current_theme) {
            $msg[] = '<div class="error"><p>';
            $msg[] = sprintf('<strong>%s</strong>: ',$current_theme->Name);
            $msg[] = sprintf('Failed to parse json string in <strong>"%s"</strong>, error: <strong>"%s"</strong>', $plugins_data_file , $errormsg);
            $msg[] = '</p></div>';
            echo implode( PHP_EOL, $msg );
        });
     }
}

 

Here's the complete implementation, save class-tgm-plugin-activation.php and the plugins.json file in YOUR-THEME-FOLDER/plugins  and add the following code to your theme functions.php file:

require_once dirname( __FILE__ ) . '/plugins/class-tgm-plugin-activation.php';
add_action( 'tgmpa_register', 'dss_theme_register_required_plugins' );


/**
 * Register the required plugins for this theme.
 *
 * In this example, we register two plugins - one included with the TGMPA library
 * and one from the .org repo.
 *
 * The variable passed to tgmpa_register_plugins() should be an array of plugin
 * arrays.
 *
 * This function is hooked into tgmpa_init, which is fired within the
 * TGM_Plugin_Activation class constructor.
 */
function dss_theme_register_required_plugins() {

    $current_theme = wp_get_theme();
    /**
     * Load plugin data from plugins/plugins.json
     *
     */
    $plugins_data_file = dirname( __FILE__ ) . '/plugins/plugins.json';
    if (file_exists($plugins_data_file)) {
        $plugins_data = file_get_contents($plugins_data_file);
        $plugins = json_decode($plugins_data,true);
        if ($plugins === null && json_last_error() !== JSON_ERROR_NONE) {
            $errormsg = json_last_error_msg();
             return add_action( 'admin_notices', function() use ( $plugins_data_file, $errormsg,  $current_theme) {
                $msg[] = '<div class="error"><p>';
                $msg[] = sprintf('<strong>%s</strong>: ',$current_theme->Name);
                $msg[] = sprintf('Failed to parse json string in <strong>"%s"</strong>, error: <strong>"%s"</strong>', $plugins_data_file , $errormsg);
                $msg[] = '</p></div>';
                echo implode( PHP_EOL, $msg );
            });
         }
    }

    /**
     * Array of configuration settings. Amend each line as needed.
     * If you want the default strings to be available under your own theme domain,
     * leave the strings uncommented.
     * Some of the strings are added into a sprintf, so see the comments at the
     * end of each line for what each argument will be.
     */
    $config = array(
        'default_path' => '',                      // Default absolute path to pre-packaged plugins.
        'menu'         => 'tgmpa-install-plugins', // Menu slug.
        'has_notices'  => true,                    // Show admin notices or not.
        'dismissable'  => false,                    // If false, a user cannot dismiss the nag message.
        'dismiss_msg'  => sprintf('<h3>%s</h3><p>%s</p>',$current_theme->Name, $current_theme->Description),                 // If 'dismissable' is false, this message will be output at top of nag.
        'is_automatic' => true,                   // Automatically activate plugins after installation or not.
        'message'      => sprintf('<h3>%s</h3><p>%s</p>',$current_theme->Name, $current_theme->Description),                     // Message to output right before the plugins table.
        'strings'      => array(
            'page_title'                      => __( 'Install Required Plugins', 'tgmpa' ),
            'menu_title'                      => __( 'Install Plugins', 'tgmpa' ),
            'installing'                      => __( 'Installing Plugin: %s', 'tgmpa' ), // %s = plugin name.
            'oops'                            => __( 'Something went wrong with the plugin API.', 'tgmpa' ),
            'notice_can_install_required'     => _n_noop( 'This theme requires the following plugin: %1$s.', 'This theme requires the following plugins: %1$s.' , 'tgmpa' ), // %1$s = plugin name(s).
            'notice_can_install_recommended'  => _n_noop( 'This theme recommends the following plugin: %1$s.', 'This theme recommends the following plugins: %1$s.', 'tgmpa'  ), // %1$s = plugin name(s).
            'notice_cannot_install'           => _n_noop( 'Sorry, but you do not have the correct permissions to install the %s plugin. Contact the administrator of this site for help on getting the plugin installed.', 'Sorry, but you do not have the correct permissions to install the %s plugins. Contact the administrator of this site for help on getting the plugins installed.', 'tgmpa'  ), // %1$s = plugin name(s).
            'notice_can_activate_required'    => _n_noop( 'The following required plugin is currently inactive: %1$s.', 'The following required plugins are currently inactive: %1$s.', 'tgmpa'  ), // %1$s = plugin name(s).
            'notice_can_activate_recommended' => _n_noop( 'The following recommended plugin is currently inactive: %1$s.', 'The following recommended plugins are currently inactive: %1$s.', 'tgmpa'  ), // %1$s = plugin name(s).
            'notice_cannot_activate'          => _n_noop( 'Sorry, but you do not have the correct permissions to activate the %s plugin. Contact the administrator of this site for help on getting the plugin activated.', 'Sorry, but you do not have the correct permissions to activate the %s plugins. Contact the administrator of this site for help on getting the plugins activated.', 'tgmpa'  ), // %1$s = plugin name(s).
            'notice_ask_to_update'            => _n_noop( 'The following plugin needs to be updated to its latest version to ensure maximum compatibility with this theme: %1$s.', 'The following plugins need to be updated to their latest version to ensure maximum compatibility with this theme: %1$s.', 'tgmpa'  ), // %1$s = plugin name(s).
            'notice_cannot_update'            => _n_noop( 'Sorry, but you do not have the correct permissions to update the %s plugin. Contact the administrator of this site for help on getting the plugin updated.', 'Sorry, but you do not have the correct permissions to update the %s plugins. Contact the administrator of this site for help on getting the plugins updated.', 'tgmpa'  ), // %1$s = plugin name(s).
            'install_link'                    => _n_noop( 'Begin installing plugin', 'Begin installing plugins', 'tgmpa'  ),
            'activate_link'                   => _n_noop( 'Begin activating plugin', 'Begin activating plugins', 'tgmpa'  ),
            'return'                          => __( 'Return to Required Plugins Installer', 'tgmpa' ),
            'plugin_activated'                => __( 'Plugin activated successfully.', 'tgmpa' ),
            'complete'                        => __( 'All plugins installed and activated successfully. %s', 'tgmpa' ), // %s = dashboard link.
            'nag_type'                        => 'updated' // Determines admin notice type - can only be 'updated', 'update-nag' or 'error'.
        )
    );
    tgmpa( $plugins, $config );
}