wp_custom_admin_dashboard.php

/*
	Custom admin dashboard
	remove unnecessary admin dashboard panel
	remove welcome panel
	remove help tab
	remove screen optons tab
	remove color scheme picker
	redirect after login
	add custom widgets
	with capabilities check example
	
	Version Tested: 3.6,3.8
	Reference:
	http://codex.wordpress.org/Roles_and_Capabilities#manage_options
	http://codex.wordpress.org/Plugin_API/Action_Reference/wp_dashboard_setup
	
*/
// Remove  WordPress Welcome Panel
remove_action('welcome_panel', 'wp_welcome_panel');


if ( !current_user_can('manage_options') ) {
	//custom dashboard widgets
	/**
	 * Add a widget to the dashboard to substitute the blank page after removing all widgets.
	 *
	 * This function is hooked into the 'wp_dashboard_setup' action below.
	 *
	 * Reference: http://codex.wordpress.org/Dashboard_Widgets_API
	 */
	
	// Remove widgets
	function wo_shop_user_dashboard_widgets() {
		global $wp_meta_boxes;
		// print_r( $wp_meta_boxes );
		unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);
		unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);
		unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']);
		unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_activity']);
		// unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);
		unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_comments']);
		unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);
		unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);
		// unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_recent_drafts']);
		// unset($wp_meta_boxes['dashboard']['normal']);
		
		wp_add_dashboard_widget(
			 'wo_shop_intro_dashboard_widget',         // Widget slug.
			 // 'Welcome to shop and profile administration',         // Title.
			 'render_wo_shop_intro_widgets' // Display function.
		);
	}
	add_action('wp_dashboard_setup', 'wo_shop_user_dashboard_widgets' );

	/**
	 * Create the function to output the contents of our Dashboard Widget.
	 */
	function render_wo_shop_intro_widgets() {
		// Display whatever it is you want to show.
	} 
	
	/*
	remove unnecessary option for normal user
	*/
	// Hide 'Screen Options' tab
	function remove_screen_options_tab() {
		return false;
	}
	add_filter('screen_options_show_screen', 'remove_screen_options_tab');

	//profile
	remove_action( 'admin_color_scheme_picker', 'admin_color_scheme_picker' );
	
	
	//redirect to default landing page after login
	function admin_default_page() {
	  $landing_page = '/wp-admin/profile.php';
	  return $landing_page;
	}
	add_filter('login_redirect', 'admin_default_page');

	function wo_shop_remove_help($old_help, $screen_id, $screen){
		$screen->remove_help_tabs();
		return $old_help;
	}
	add_filter( 'contextual_help', 'wo_shop_remove_help', 999, 3 );
}