Gradle插件DSL : Restriction on declaration location

Question

我有一些通过apply from: 'my-build.gradle'应用的Gradle脚本。如果我在外部构建文件my-build.gradle中按如下方式使用新的插件DSL，它将失败并显示以下错误:

> startup failed:
  Only Project build scripts can contain plugins {} blocks
  See http://gradle.org/docs/2.3/userguide/plugins.html#sec:plugins_block 
  for information on the plugins {} block

查看错误消息中指出的文档并没有揭示限制原因。为什么对插件声明的位置有限制？

引用文件如下。

my-build.gradle文件:

plugins {
    id "net.saliman.cobertura" version "2.2.5"
}

build.gradle文件:

apply from: "my-build.gradle"

// Other stuff

Answer 1

这是您可以在外部Gradle文件(例如my-build.gradle)中使用插件的方式:

buildscript {
  repositories {
    mavenCentral()
    maven { url "https://plugins.gradle.org/m2/" }
  }
  dependencies {
    classpath "org.sonarqube.gradle:gradle-sonarqube-plugin:1.1"
    classpath "net.saliman:gradle-cobertura-plugin:2.2.8"
  }
}
// Because this is a helper script that's sourced in from a build.gradle, we can't use the ID of external plugins
// We either use the full class name of the plugin without quotes or an init script: http://www.gradle.org/docs/current/userguide/init_scripts.html
apply plugin: org.sonarqube.gradle.SonarQubePlugin
apply plugin: net.saliman.gradle.plugin.cobertura.CoberturaPlugin

// rest of my-build.gradle omitted

在上面，我已经激活了 SonarQube和 Cobertura的插件。

通常，要获取插件的完全合格的类名称，您必须查看其 .jar文件内部。

至于技术原因，为什么您不能在外部文件中使用 plugins {}块，我不知道。它可能需要对 following做一些事情:

[...] plugins [need to] be specified in a way that Gradle can easily and quickly extract [them], before executing the rest of the build script. It also requires that the definition of plugins to use be somewhat static.

但是 rejoice:

Future versions of Gradle will remove this restriction.