// Copyright 2017 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import 'package:args/args.dart'; import 'context.dart'; /// command-line flags and options that were specified during the invocation of /// the Flutter tool. Flags get flags => context?.getVariable(Flags) ?? const _EmptyFlags(); /// Encapsulation of the command-line flags and options that were specified /// during the invocation of the Flutter tool. /// /// An instance of this class is set into the [AppContext] upon invocation of /// the Flutter tool (immediately after the arguments have been parsed in /// [FlutterCommandRunner]) and is available via the [flags] global property. class Flags { Flags(this._globalResults) : assert(_globalResults != null); final ArgResults _globalResults; /// Gets the value of the specified command-line flag/option that was set /// during the invocation of the Flutter tool. /// /// This will first search for flags that are specific to the command and will /// fall back to global flags. /// /// If a flag has a default value and the user did not explicitly specify a /// value on the command-line, this will return the default value. /// /// If the specified flag is not defined or was not specified and had no /// default, then this will return `null`. dynamic operator [](String key) { final ArgResults commandResults = _globalResults.command; final Iterable<String> options = commandResults?.options; if (options != null && options.contains(key)) return commandResults[key]; else if (_globalResults.options.contains(key)) return _globalResults[key]; return null; } /// `true` iff the given flag/option was either explicitly specified by the /// user at the command-line or it was defined to have a default value. bool contains(String key) { final ArgResults commandResults = _globalResults.command; final Iterable<String> options = commandResults?.options; return (options != null && options.contains(key)) || _globalResults.options.contains(key); } } class _EmptyFlags implements Flags { const _EmptyFlags(); @override ArgResults get _globalResults => null; @override String operator [](String key) => null; @override bool contains(String key) => false; }