如何在执行Gradle任务的依赖项之前执行某些操作？

Question

我有以下内容build.gradle:

task aoeu << {
    println "**************************** during"
}

tasks.publish.dependsOn(aoeu)

tasks.publish.doFirst {
    println "************************* before"
}

tasks.publish.doLast {
    println "************************* after"
}

它的输出是:

:aoeu
**************************** during
:publish
************************* before
************************* after

但我真正需要的是''在'之前'和之后'之间'发生'.如何才能做到这一点？"发布"应该仅仅取决于"之前"吗？如果是这样,我怎样才能保证它在其他依赖项之前发生？

Answer 1

据我所知,你的代码应该可以正常运行,但事实并非如此.doFirst应该在执行阶段doLast(执行阶段)之前运行的配置阶段执行.BTW这段代码工作正常:

正如Peter Niederwiser在这里写的那样/sf/answers/644291161/ doFirst在执行阶段作为第一个语句(之前doLast)运行,所以你的代码工作正常.此示例将显示gradle构建中的执行顺序:

task publish {
    println "(1) before (run in configuration phase)" // this will run before gradle dependencies
}

task aoeu << {
    println "(2) during  (run in execution phase as last statement)"
}

tasks.publish.dependsOn(aoeu)
tasks.publish.doLast {
    println "(4) after  (run in execution phase as last statement)"
}

tasks.publish.doFirst {
    println "(3) after  (run in execution phase as FORST statement - before doLast/<<)"
}

它会回来

C:\>gradle publish
(1) before (run in configuration phase)
:aoeu
(2) during  (run in execution phase as last statement)
:publish
(3) after  (run in execution phase as FORST statement - before doLast/<<)
(4) after  (run in execution phase as last statement)

[UPDATE]

这里http://gradle.1045684.n5.nabble.com/task-run-order-lt-lt-syntax-doLast-doFirst-etc-td3337481.html是一个很好的例子,它显示了执行顺序.

阅读这篇关于gradle生命周期的文章,它将帮助您理解它.

[更新] 如果你想运行的任务aoeu在publish执行阶段,你可以调用aoeu.execute的publish.doFirst.但据我所知,不应该这样做.

task publish {
}

task aoeu << {
    println "(2) during  (run in execution phase as last statement)"
}

tasks.publish.doLast {
    println "(3) after  (run in execution phase as last statement)"
}

tasks.publish.doFirst {
    println "(1) after  (run in execution phase as FORST statement - before doLast/<<)"
    aoeu.execute()
}

将返回

C:\>gradle publish
:publish
(1) after  (run in execution phase as FORST statement - before doLast/<<)
(2) during  (run in execution phase as last statement)
(3) after  (run in execution phase as last statement)

正如我所见,你想aoeu在publish任务中运行.我认为最好的方法是将publish任务分成两个单独的任务并使用depends,mustRunAfter来控制执行顺序.看看这个例子:

task publishInit << {
    println '(1)'
}

task aoeu << {
    println '(2)'
}

task publish << {
    println '(3)'
}

publish.dependsOn publishInit
publish.dependsOn aoeu
aoeu.mustRunAfter publishInit

它会回来

C:\>gradle publish
:publishInit
(1)
:aoeu
(2)
:publish
(3)

Answer 2

task snth << {
    println "************************* before"
}

task aoeu << {
    println "**************************** during aoeu"
}
publish.dependsOn(aoeu)

task ueoa << {
    println "**************************** during ueoa"
}
publish.dependsOn(ueoa)

publish.doLast {
    println "************************* after"
}

publish.dependsOn.each { dependency ->
    if (dependency instanceof Task) {
        dependency.dependsOn(snth)
    }
}

将输出：

:snth
************************* before
:aoeu
**************************** during aoeu
:ueoa
**************************** during ueoa
:publish
************************* after

如果您希望递归添加依赖项：

def recursivelyAddDependsOn(Task parent, Task dependsOn) {
    if (!parent.equals(dependsOn)) {
        parent.dependsOn(dependsOn)

        def tasks = parent.dependsOn.findAll { dependency ->
            dependency instanceof Task
        }
        tasks.each { task ->
            recursivelyAddDependsOn(task, dependsOn)
        }
    }
}

recursivelyAddDependsOn(publish, snth)

更实用的解决方案是：

def recursivelyApplyToTaskDependencies(Task parent, Closure closure) {
    closure(parent)

    parent.dependsOn.findAll { dependency ->
        dependency instanceof Task
    }.each { task ->
        recursivelyApplyToTaskDependencies(task, closure)
    }
}

def recursivelyAddTaskDependency(Task parent, Task dependency) {
    def addTaskDependency = { p ->
        if (!p.name.equals(dependency.name)) {
            p.dependsOn(dependency)
        }
    }

    recursivelyApplyToTaskDependencies(parent, addTaskDependency)
}

recursivelyAddTaskDependency(publish, snth)