現(xiàn)狀

Flutter官方的執(zhí)行方案對(duì)Flutter工程及環(huán)境有很強(qiáng)的依賴性痪宰，非Flutter的成員在對(duì)iOS主工程進(jìn)行迭代開發(fā)時(shí)需要依賴Flutter環(huán)境料扰，團(tuán)隊(duì)合作十分不便斧吐。在通過Jenkins等打包時(shí)會(huì)有各種問題蔗蹋。

官方文章地址：Add Flutter to existing apps?

基于Flutter版本1.9.1+hotfix 4

適用于以flutter module進(jìn)行開發(fā)锨天，作為iOS一個(gè)組件來引入的情況

（可以直接跳至方案查看結(jié)果）

期望

flutter 集成進(jìn)iOS項(xiàng)目脫離Flutter環(huán)境及工程，F(xiàn)lutter工程開發(fā)與iOS原生開發(fā)互不影響缔恳。

分析

Flutter執(zhí)行build之后產(chǎn)物介紹

在Flutter的module中執(zhí)行flutter build ios --release后宝剖，我們的工程目錄里有隱藏文件夾.ios，我們需要的Flutter產(chǎn)物基本都在其下的Flutter文件夾中歉甚。

image-20191031164025401.png

挨個(gè)分析一下內(nèi)部我們需要的文件万细。

• .symlinks

  我們?nèi)綆斓乃饕瑑?nèi)部每個(gè)文件夾下纸泄，都包含ios文件夾赖钞，這個(gè)文件夾下都是一個(gè)pod庫。

• App.framework

  Flutter項(xiàng)目的Dart代碼編譯而成的Framework聘裁。

• engine

  Flutter的引擎Framework雪营，一個(gè)pod庫。

• FlutterPluginRegistrant

  Flutter三方庫的注冊(cè)入口衡便，一個(gè)pod庫献起。

• Generated.xcconfig

  Flutter的路徑信息，配置信息等镣陕。

• podhelper.rb

  pod執(zhí)行的時(shí)候用到的腳本征唬。后續(xù)會(huì)對(duì)這個(gè)文件做具體的分析

• 其他的文件基本都沒什么用處可以不關(guān)注

官方方案分析

官方執(zhí)行步驟：

1. 在Podfile中加入如下代碼：

flutter_application_path = 'path/to/my_flutter/'
load File.join(flutter_application_path, '.ios', 'Flutter', 'podhelper.rb')

2. 對(duì)每個(gè)Xcode target添加方法install_all_flutter_pods(flutter_application_path)

target 'MyApp' do
     install_all_flutter_pods(flutter_application_path)
end
target 'MyAppTests' do
     install_all_flutter_pods(flutter_application_path)
end

分析：

第一步作用是設(shè)置flutter工程路徑并添加腳本podhelper.rb。

第二步作用就是執(zhí)行podhelper.rb中的方法install_all_flutter_pods茁彭，并將flutter工程路徑變量傳入。

那么下面我們來分析一下這個(gè)podhelper.rb中到底做了什么扶歪。

分析podhelper.rb

腳本代碼如下：

# Install pods needed to embed Flutter application, Flutter engine, and plugins
# from the host application Podfile.
#
# @example
#   target 'MyApp' do
#     install_all_flutter_pods 'my_flutter'
#   end
# @param [String] flutter_application_path Path of the root directory of the Flutter module.
#                                          Optional, defaults to two levels up from the directory of this script.
#                                          MyApp/my_flutter/.ios/Flutter/../..
def install_all_flutter_pods(flutter_application_path = nil)
  flutter_application_path ||= File.join('..', '..')
  install_flutter_engine_pod
#  install_flutter_plugin_pods(flutter_application_path)
  install_flutter_application_pod(flutter_application_path)
end

# Install Flutter engine pod.
#
# @example
#   target 'MyApp' do
#     install_flutter_engine_pod
#   end
def install_flutter_engine_pod
  engine_dir = File.join(__dir__, 'engine')
  if !File.exist?(engine_dir)
    # Copy the debug engine to have something to link against if the xcode backend script has not run yet.
    # CocoaPods will not embed the framework on pod install (before any build phases can generate) if the dylib does not exist.
    debug_framework_dir = File.join(flutter_root, 'bin', 'cache', 'artifacts', 'engine', 'ios')
    FileUtils.mkdir_p(engine_dir)
    FileUtils.cp_r(File.join(debug_framework_dir, 'Flutter.framework'), engine_dir)
    FileUtils.cp(File.join(debug_framework_dir, 'Flutter.podspec'), engine_dir)
  end

  # Keep pod path relative so it can be checked into Podfile.lock.
  # Process will be run from project directory.
  engine_pathname = Pathname.new engine_dir
  project_directory_pathname = Pathname.new Dir.pwd
  relative = engine_pathname.relative_path_from project_directory_pathname

  pod 'Flutter', :path => relative.to_s, :inhibit_warnings => true
end

# Install Flutter plugin pods.
#
# @example
#   target 'MyApp' do
#     install_flutter_plugin_pods 'my_flutter'
#   end
# @param [String] flutter_application_path Path of the root directory of the Flutter module.
#                                          Optional, defaults to two levels up from the directory of this script.
#                                          MyApp/my_flutter/.ios/Flutter/../..
#def install_flutter_plugin_pods(flutter_application_path)
#  flutter_application_path ||= File.join('..', '..')
#
#  # Keep pod path relative so it can be checked into Podfile.lock.
#  # Process will be run from project directory.
#  current_directory_pathname = Pathname.new __dir__
#  project_directory_pathname = Pathname.new Dir.pwd
#  relative = current_directory_pathname.relative_path_from project_directory_pathname
#  pod 'FlutterPluginRegistrant', :path => File.join(relative, 'FlutterPluginRegistrant'), :inhibit_warnings => true
#
#  symlinks_dir = File.join(relative, '.symlinks')
#  FileUtils.mkdir_p(symlinks_dir)
#  plugin_pods = parse_KV_file(File.join(flutter_application_path, '.flutter-plugins'))
#  plugin_pods.map do |r|
#    symlink = File.join(symlinks_dir, r[:name])
#    FileUtils.rm_f(symlink)
#    File.symlink(r[:path], symlink)
#    pod r[:name], :path => File.join(symlink, 'ios'), :inhibit_warnings => true
#  end
#end

# Install Flutter application pod.
#
# @example
#   target 'MyApp' do
#     install_flutter_application_pod '../flutter_settings_repository'
#   end
# @param [String] flutter_application_path Path of the root directory of the Flutter module.
#                                          Optional, defaults to two levels up from the directory of this script.
#                                          MyApp/my_flutter/.ios/Flutter/../..
def install_flutter_application_pod(flutter_application_path)
  app_framework_dir = File.join(__dir__, 'App.framework')
  app_framework_dylib = File.join(app_framework_dir, 'App')
  if !File.exist?(app_framework_dylib)
    # Fake an App.framework to have something to link against if the xcode backend script has not run yet.
    # CocoaPods will not embed the framework on pod install (before any build phases can run) if the dylib does not exist.
    # Create a dummy dylib.
    FileUtils.mkdir_p(app_framework_dir)
    `echo "static const int Moo = 88;" | xcrun clang -x c -dynamiclib -o "#{app_framework_dylib}" -`
  end

  # Keep pod and script phase paths relative so they can be checked into source control.
  # Process will be run from project directory.
  current_directory_pathname = Pathname.new __dir__
  project_directory_pathname = Pathname.new Dir.pwd
  relative = current_directory_pathname.relative_path_from project_directory_pathname
  pod 'flutter_module', :path => relative.to_s, :inhibit_warnings => true

#  flutter_export_environment_path = File.join('${SRCROOT}', relative, 'flutter_export_environment.sh');
#  script_phase :name => 'Run Flutter Build Script',
#  :script => "set -e\nset -u\nsource \"#{flutter_export_environment_path}\"\n../xcode_backend.sh build",
##  :script => "set -e\nset -u\nsource \"#{flutter_export_environment_path}\"\n\"$FLUTTER_ROOT\"/packages/flutter_tools/bin/xcode_backend.sh build",
#
#  :input_files => [
#      File.join('${SRCROOT}', flutter_application_path, '.metadata'),
#      File.join('${SRCROOT}', relative, 'App.framework', 'App'),
#      File.join('${SRCROOT}', relative, 'engine', 'Flutter.framework', 'Flutter'),
#      flutter_export_environment_path
#    ],
#    :execution_position => :before_compile
end

#def parse_KV_file(file, separator='=')
#  file_abs_path = File.expand_path(file)
#  if !File.exists? file_abs_path
#    return [];
#  end
#  pods_array = []
#  skip_line_start_symbols = ["#", "/"]
#  File.foreach(file_abs_path) { |line|
#    next if skip_line_start_symbols.any? { |symbol| line =~ /^\s*#{symbol}/ }
#    plugin = line.split(pattern=separator)
#    if plugin.length == 2
#      podname = plugin[0].strip()
#      path = plugin[1].strip()
#      podpath = File.expand_path("#{path}", file_abs_path)
#      pods_array.push({:name => podname, :path => podpath});
#     else
#      puts "Invalid plugin specification: #{line}"
#    end
#  }
#  return pods_array
#end

#def flutter_root
#  generated_xcode_build_settings = parse_KV_file(File.join(__dir__, 'Generated.xcconfig'))
#  if generated_xcode_build_settings.empty?
#    puts "Generated.xcconfig must exist. Make sure `flutter pub get` is executed in the Flutter module."
#    exit
#  end
#  generated_xcode_build_settings.map { |p|
#    if p[:name] == 'FLUTTER_ROOT'
#      return p[:path]
#    end
#  }
#end

解釋一下理肺，這個(gè)腳本未注釋的部分做了兩件事：

• 引入Flutter引擎install_flutter_engine_pod
• 引入Flutter工程編譯后的Framework摄闸，install_flutter_application_pod

如果是執(zhí)行flutter build ios --debug會(huì)把這個(gè)腳本里的已注釋代碼部分取消注釋。原因是release模式會(huì)把第三方庫的東西都統(tǒng)一編譯到App.framework內(nèi)妹萨，debug不會(huì)年枕，所以在debug時(shí)會(huì)把第三方庫分別引入。

方案

綜上乎完，我們的方案步驟如下：

1. 在flutter_module工程里執(zhí)行flutter build ios --release方法熏兄，在工程目錄里找到.ios文件夾

2. 復(fù)制出來Flutter文件夾下的engine目錄，App.framework及flutter module的podspec文件树姨。

3. 將app.framework及podspec放入一個(gè)文件夾摩桶，engine放入另一個(gè)文件夾。

4. podfile里面添加

   pod 'Flutter', :path => 'path to engine'
   pod 'flutter module 的name', :path => 'path to app.framework'
   

執(zhí)行pod install就好了

此外帽揪，也可以把這兩個(gè)pod庫放入git倉庫等進(jìn)行管理硝清。

參考文章：

Flutter遠(yuǎn)程依賴簡(jiǎn)單實(shí)踐
Flutter iOS 混合工程自動(dòng)化

歡迎大家拍磚