"isClient", "isServer", "isDartClient", "isJsClient" properties to check if the Dart application is running whether on Javascript enabled browser, on Chronium browser, or as a server process.

vmcheck.dart

library vmcheck;

import 'package:path/src/style.dart';

// This snippet is for Dart >= 1.1

bool get isClient => Style.platform == Style.url;

bool get isServer => Style.platform != Style.url;

// Uncomment to check if this application is running on Dart-enabled-browser or not.
//
//import 'dart:html';
//
//bool get _isDart => document.getElementsByTagName("script").where((s) => s.src.endsWith(".dart.js")).isEmpty;
//
//bool get isDartClient => isClient && _isDart;
//
//bool get isJsClient => isClient && !_isDart;

vmcheck_older.dart

library vmcheck_older;

// This snippet is for Dart =< 1.0 
// Checking method is based on the code found in earlier version of Dart 'path library'.

import 'dart:mirrors';

/// If we're running in the server-side Dart VM, this will return a
/// [LibraryMirror] that gives access to the `dart:io` library.
///
/// If `dart:io` is not available, this returns null.
LibraryMirror get _io => currentMirrorSystem().libraries[Uri.parse('dart:io')];

/// If we're running in Dartium, this will return a [LibraryMirror] that gives
/// access to the `dart:html` library.
///
/// If `dart:html` is not available, this returns null.
LibraryMirror get _html =>
  currentMirrorSystem().libraries[Uri.parse('dart:html')];

bool get isClient => _io == null;

bool get isServer => _io != null;

bool get isDartClient => isClient && _html == null;

bool get isJsClient => isClient && _html != null;

This snippet has become a single package available from "pub" repository.

• http://pub.dartlang.org/packages/is_client
• https://github.com/hyamamoto/is_client.dart