Update for null safety.

example/ios/Flutter/Flutter.podspec

@@ -1,18 +1,18 @@
 #
 # NOTE: This podspec is NOT to be published. It is only used as a local source!
+#       This is a generated file; do not edit or check into version control.
 #
 
 Pod::Spec.new do |s|
   s.name             = 'Flutter'
   s.version          = '1.0.0'
   s.summary          = 'High-performance, high-fidelity mobile apps.'
-  s.description      = <<-DESC
-Flutter provides an easy and productive way to build and deploy high-performance mobile apps for Android and iOS.
-                       DESC
   s.homepage         = 'https://flutter.io'
   s.license          = { :type => 'MIT' }
   s.author           = { 'Flutter Dev Team' => '[email protected]' }
   s.source           = { :git => 'https://github.com/flutter/engine', :tag => s.version.to_s }
   s.ios.deployment_target = '8.0'
-  s.vendored_frameworks = 'Flutter.framework'
+  # Framework linking is handled by Flutter tooling, not CocoaPods.
+  # Add a placeholder to satisfy `s.dependency 'Flutter'` plugin podspecs.
+  s.vendored_frameworks = 'path/to/nothing'
 end

example/ios/Podfile

@@ -10,78 +10,29 @@ project 'Runner', {
   'Release' => :release,
 }
 
-def parse_KV_file(file, separator='=')
-  file_abs_path = File.expand_path(file)
-  if !File.exists? file_abs_path
-    return [];
+def flutter_root
+  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'Generated.xcconfig'), __FILE__)
+  unless File.exist?(generated_xcode_build_settings_path)
+    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure flutter pub get is executed first"
   end
-  generated_key_values = {}
-  skip_line_start_symbols = ["#", "/"]
-  File.foreach(file_abs_path) do |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)
-      generated_key_values[podname] = podpath
-    else
-      puts "Invalid plugin specification: #{line}"
-    end
-  end
-  generated_key_values
-end
-
-target 'Runner' do
-  # Flutter Pod
-
-  copied_flutter_dir = File.join(__dir__, 'Flutter')
-  copied_framework_path = File.join(copied_flutter_dir, 'Flutter.framework')
-  copied_podspec_path = File.join(copied_flutter_dir, 'Flutter.podspec')
-  unless File.exist?(copied_framework_path) && File.exist?(copied_podspec_path)
-    # Copy Flutter.framework and Flutter.podspec to Flutter/ to have something to link against if the xcode backend script has not run yet.
-    # That script will copy the correct debug/profile/release version of the framework based on the currently selected Xcode configuration.
-    # CocoaPods will not embed the framework on pod install (before any build phases can generate) if the dylib does not exist.
 
-    generated_xcode_build_settings_path = File.join(copied_flutter_dir, 'Generated.xcconfig')
-    unless File.exist?(generated_xcode_build_settings_path)
-      raise "Generated.xcconfig must exist. If you're running pod install manually, make sure flutter pub get is executed first"
-    end
-    generated_xcode_build_settings = parse_KV_file(generated_xcode_build_settings_path)
-    cached_framework_dir = generated_xcode_build_settings['FLUTTER_FRAMEWORK_DIR'];
-
-    unless File.exist?(copied_framework_path)
-      FileUtils.cp_r(File.join(cached_framework_dir, 'Flutter.framework'), copied_flutter_dir)
-    end
-    unless File.exist?(copied_podspec_path)
-      FileUtils.cp(File.join(cached_framework_dir, 'Flutter.podspec'), copied_flutter_dir)
-    end
+  File.foreach(generated_xcode_build_settings_path) do |line|
+    matches = line.match(/FLUTTER_ROOT\=(.*)/)
+    return matches[1].strip if matches
   end
+  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Generated.xcconfig, then run flutter pub get"
+end
 
-  # Keep pod path relative so it can be checked into Podfile.lock.
-  pod 'Flutter', :path => 'Flutter'
+require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)
 
-  # Plugin Pods
+flutter_ios_podfile_setup
 
-  # Prepare symlinks folder. We use symlinks to avoid having Podfile.lock
-  # referring to absolute paths on developers' machines.
-  system('rm -rf .symlinks')
-  system('mkdir -p .symlinks/plugins')
-  plugin_pods = parse_KV_file('../.flutter-plugins')
-  plugin_pods.each do |name, path|
-    symlink = File.join('.symlinks', 'plugins', name)
-    File.symlink(path, symlink)
-    pod name, :path => File.join(symlink, 'ios')
-  end
+target 'Runner' do
+  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
 end
 
-# Prevent Cocoapods from embedding a second Flutter framework and causing an error with the new Xcode build system.
-install! 'cocoapods', :disable_input_output_paths => true
-
 post_install do |installer|
   installer.pods_project.targets.each do |target|
-    target.build_configurations.each do |config|
-      config.build_settings['ENABLE_BITCODE'] = 'NO'
-    end
+    flutter_additional_ios_build_settings(target)
   end
 end

example/ios/Podfile.lock

@@ -1,22 +1,16 @@
 PODS:
   - Flutter (1.0.0)
-  - flutter_native_timezone (0.0.1):
-    - Flutter
 
 DEPENDENCIES:
   - Flutter (from `Flutter`)
-  - flutter_native_timezone (from `.symlinks/plugins/flutter_native_timezone/ios`)
 
 EXTERNAL SOURCES:
   Flutter:
     :path: Flutter
-  flutter_native_timezone:
-    :path: ".symlinks/plugins/flutter_native_timezone/ios"
 
 SPEC CHECKSUMS:
-  Flutter: 0e3d915762c693b495b44d77113d4970485de6ec
-  flutter_native_timezone: e72ff1900460ff57cfd331d1758050c9269f3e99
+  Flutter: 434fef37c0980e73bb6479ef766c45957d4b510c
 
-PODFILE CHECKSUM: 3dbe063e9c90a5d7c9e4e76e70a821b9e2c1d271
+PODFILE CHECKSUM: 8e679eca47255a8ca8067c4c67aab20e64cb974d
 
-COCOAPODS: 1.8.4
+COCOAPODS: 1.10.1

example/ios/Runner.xcodeproj/project.pbxproj

@@ -151,7 +151,6 @@
 				97C146EC1CF9000F007C117D /* Resources */,
 				9705A1C41CF9048500538489 /* Embed Frameworks */,
 				3B06AD1E1E4923F5004D2608 /* Thin Binary */,
-				861A800CC8D09610E2D0AF23 /* [CP] Embed Pods Frameworks */,
 			);
 			buildRules = (
 			);
@@ -224,21 +223,6 @@
 			shellPath = /bin/sh;
 			shellScript = "/bin/sh \"$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh\" embed_and_thin";
 		};
-		861A800CC8D09610E2D0AF23 /* [CP] Embed Pods Frameworks */ = {
-			isa = PBXShellScriptBuildPhase;
-			buildActionMask = 2147483647;
-			files = (
-			);
-			inputPaths = (
-			);
-			name = "[CP] Embed Pods Frameworks";
-			outputPaths = (
-			);
-			runOnlyForDeploymentPostprocessing = 0;
-			shellPath = /bin/sh;
-			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-Runner/Pods-Runner-frameworks.sh\"\n";
-			showEnvVarsInLog = 0;
-		};
 		9740EEB61CF901F6004384FC /* Run Script */ = {
 			isa = PBXShellScriptBuildPhase;
 			buildActionMask = 2147483647;
@@ -312,7 +296,6 @@
 /* Begin XCBuildConfiguration section */
 		249021D3217E4FDB00AE95B9 /* Profile */ = {
 			isa = XCBuildConfiguration;
-			baseConfigurationReference = 7AFA3C8E1D35360C0083082E /* Release.xcconfig */;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_ANALYZER_NONNULL = YES;
@@ -384,7 +367,6 @@
 		};
 		97C147031CF9000F007C117D /* Debug */ = {
 			isa = XCBuildConfiguration;
-			baseConfigurationReference = 9740EEB21CF90195004384FC /* Debug.xcconfig */;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_ANALYZER_NONNULL = YES;
@@ -438,7 +420,6 @@
 		};
 		97C147041CF9000F007C117D /* Release */ = {
 			isa = XCBuildConfiguration;
-			baseConfigurationReference = 7AFA3C8E1D35360C0083082E /* Release.xcconfig */;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_ANALYZER_NONNULL = YES;

lib/flutter_native_timezone.dart

@@ -8,14 +8,20 @@ class FlutterNativeTimezone {
 
   /// Returns local timezone
   static Future<String> getLocalTimezone() async {
-    final String localTimezone =
+    final String? localTimezone =
         await _channel.invokeMethod("getLocalTimezone");
+    if (localTimezone == null ) {
+      throw ArgumentError("Invalid return from platform getLocalTimezone()");
+    }
     return localTimezone;
   }
 
   static Future<List<String>> getAvailableTimezones() async {
-    final List<String> availableTimezones =
+    final List<String>? availableTimezones =
         await _channel.invokeListMethod<String>("getAvailableTimezones");
+    if (availableTimezones == null ) {
+      throw ArgumentError("Invalid return from platform getAvailableTimezones()");
+    }
     return availableTimezones;
   }
 }