Control version from api and local version.

version_handler.dart

import 'package:package_info/package_info.dart';

/// Helper functions for version handling.
/// Note: For functions that only manipulate version conversions/formatting
class VersionHandler {
  /// Validates a version object and returns true or false, e.g. major: 1, minor: 0, patch: 1 returns true
  static bool isValidVersionObject(obj) {
    return (obj.major is int && obj.minor is int && obj.patch is int && (obj.major != null && obj.minor != null && obj.patch != null) && (obj.major != 0 || obj.minor != 0 || obj.patch != 0));
  }

  /// Converts a version string
  /// Example:
  /// '2.4.1' to an object with:
  /// - major (2)
  /// - minor (4)
  /// - patch (1)
  static AppVersion parseVersionString(str) {
    if (!(str is String)) {
      debugPrint('version string $str has invalid format');
      throw 'version string ' + str + ' has invalid format';
    }
    var x = str.split('.');
    var maj = int.parse(x[0], radix: 10);
    var min = int.parse(x[1], radix: 10);
    var pat = int.parse(x[2], radix: 10);
    var versionObj = new AppVersion(major: maj, minor: min, patch: pat);
    if (!isValidVersionObject(versionObj)) {
      debugPrint('version string $str has invalid format');
      throw 'version string ' + str + ' has invalid format';
    }
    return versionObj;
  }

  /// Gets the [appVersion] and the [apiVersion] and checks if there is a new version to trigger the out of date warning
  static bool outdatedVersion(String appVersion, String apiVersion) {
    AppVersion runningVersion = parseVersionString(appVersion);
    AppVersion latestVersion = parseVersionString(apiVersion);

    if (runningVersion.major > latestVersion.major) {
      return false;
    }
    // 'A major new update is available!'
    if (runningVersion.major < latestVersion.major) {
      debugPrint('A major new update is available!');
      return true;
    }
    // Running version is a minor upgrade over the minimum version
    if (runningVersion.minor > latestVersion.minor) {
      debugPrint('Running version is a minor upgrade over the minimum version');
      return false;
    }
    // 'A new minor update is available.'
    if (runningVersion.minor < latestVersion.minor) {
      debugPrint('A new minor update is available.');
      return true;
    }
    // Running version is a patch upgrade over the minimum version
    if (runningVersion.patch > latestVersion.patch) {
      debugPrint('Running version is a patch upgrade over the minimum version');
      return false;
    }
    // 'A new patch update is available.'
    if (runningVersion.patch < latestVersion.patch) {
      debugPrint('A new patch update is available.');
      return true;
    }
    // 'We are running the latest version! No need to update.'
    debugPrint('We are running the latest version! No need to update.');
    return false;
  }

  /// Deals with the version number if there are special versions with dashes
  /// Examples:
  /// [number] = 1.0.0-dev -> output: 1.0.0
  static String formatVersionNumber(number) {
    var splitString = number.split('-');
    return splitString[0];
  }

  /// Gets the app current version number
  static Future<String> getCurrentAppVersion() async {
    var package = await PackageInfo.fromPlatform();
    return formatVersionNumber(package.version);
  }
}