如何从 Gradle 的“pluginManagement {}”块调用函数？

问：

介绍

嗨，我正在尝试对在我的应用程序中找到的代码进行重复数据删除。这是我的文件目前的样子：settings.gradle

pluginManagement {
    def localPropertiesFile = new File(rootProject.projectDir, "local.properties")
    def properties = new Properties()
    assert localPropertiesFile.exists()
    localPropertiesFile.withReader("UTF-8") { reader -> properties.load(reader) }
    def flutterSdkPath = properties.getProperty("flutter.sdk")
    assert flutterSdkPath != null, "flutter.sdk not set in local.properties"

    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")

    plugins {
        id "dev.flutter.flutter-gradle-plugin" version "1.0.0" apply false
    }
}

include ':app'

def localPropertiesFile = new File(rootProject.projectDir, "local.properties")
def properties = new Properties()
assert localPropertiesFile.exists()
localPropertiesFile.withReader("UTF-8") { reader -> properties.load(reader) }
def flutterSdkPath = properties.getProperty("flutter.sdk")
assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
apply from: "$flutterSdkPath/packages/flutter_tools/gradle/app_plugin_loader.gradle"

（你可以忽略特定于技术的事情，以及为什么它必须这样做——让我们假设它必须这样做。如果你对更多细节感兴趣，请看这个 Flutter 的 PR)

很容易看出，负责从文件加载属性的代码重复了两次。因此，我开始删除这种重复。flutter.sdklocal.properties

尝试 1（可变）

起初，我尝试了以下代码，但很快被 Gradle 提醒“pluginManagement {} 块必须出现在脚本中的任何其他语句之前”。

def localPropertiesFile = new File(rootProject.projectDir, "local.properties")
def properties = new Properties()
assert localPropertiesFile.exists()
localPropertiesFile.withReader("UTF-8") { reader -> properties.load(reader) }
def flutterSdkPath = properties.getProperty("flutter.sdk")
assert flutterSdkPath != null, "flutter.sdk not set in local.properties"

pluginManagement {
    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")

    plugins {
        id "dev.flutter.flutter-gradle-plugin" version "1.0.0" apply false
    }
}

include ':app'

apply from: "$flutterSdkPath/packages/flutter_tools/gradle/app_plugin_loader.gradle"

尝试 2（功能）

上一次尝试中的错误消息指出，在块之前不允许任何语句。我考虑过将代码移动到一个单独的函数中，因为根据我的（适度）理解，函数不是 Groovy 中的语句：pluginManagement {}

String flutterSdkPath() {
    def localPropertiesFile = new File(rootProject.projectDir, "local.properties")
    def properties = new Properties()
    assert localPropertiesFile.exists()
    localPropertiesFile.withReader("UTF-8") { reader -> properties.load(reader) }
    def flutterSdkPath = properties.getProperty("flutter.sdk")
    assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
    return flutterSdkPath
}

pluginManagement {
    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")

    plugins {
        id "dev.flutter.flutter-gradle-plugin" version "1.0.0" apply false
    }
}

include ':app'

apply from: "$flutterSdkPath/packages/flutter_tools/gradle/app_plugin_loader.gradle"

不幸的是，它仍然不起作用，并且错误只会变得不那么有用：

FAILURE: Build failed with an exception.

* Where:
Settings file '/Users/bartek/fvm/versions/master/examples/hello_world/android/settings.gradle' line: 20

* What went wrong:
A problem occurred evaluating settings 'android'.
> Could not get unknown property 'flutterSdkPath' for object of type org.gradle.plugin.management.internal.DefaultPluginManagementSpec.

我很确定它必须与 Gradle 以特殊方式处理的阻止有关（也就是说，在评估其余代码之前，首先对其进行评估）pluginManagement {}settings.gradle

尝试 3（类中的静态方法）

我想也许块之前的所有代码都以某种方式被剥离了（？），所以我尝试创建一个带有静态方法的类：pluginManagement {}

pluginManagement {
    includeBuild("${Flutter.flutterSdkPath}/packages/flutter_tools/gradle")

    plugins {
        id "dev.flutter.flutter-gradle-plugin" version "1.0.0" apply false
    }
}

include ':app'

apply from: "${Flutter.flutterSdkPath}/packages/flutter_tools/gradle/app_plugin_loader.gradle"

class Flutter {
    String flutterSdkPath() {
        def localPropertiesFile = new File(rootProject.projectDir, "local.properties")
        def properties = new Properties()
        assert localPropertiesFile.exists()
        localPropertiesFile.withReader("UTF-8") { reader -> properties.load(reader) }
        def flutterSdkPath = properties.getProperty("flutter.sdk")
        assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
        return flutterSdkPath
    }
}

这一次，错误消息就更没用了：

* Where:
Settings file '/Users/bartek/fvm/versions/master/examples/hello_world/android/settings.gradle' line: 11

* What went wrong:
A problem occurred evaluating settings 'android'.
> Flutter

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

使用标志运行 Gradle 后，我注意到这一行：--stracktrace

... (<very long stack trace>)
Caused by: java.lang.NoClassDefFoundError: Flutter
...

看起来与我在尝试 2 中遇到的问题相同）。

关于如何将属性加载代码移动到一个地方并从块内部和外部调用它，我没有更多的想法。pluginManagement {}

我认为 Gradle 设置插件可以在这里工作，但除非必要，否则我宁愿不这样做。