将任务添加到 sbt 13.x build.sbt

Question

我已将此添加到 build.sbt

libraryDependencies += "com.typesafe.slick" %% "slick-codegen" % "2.1.0"

lazy val slickGenerate = TaskKey[Seq[File]]("slick code generation")

slickGenerate <<= slickGenerateTask 

lazy val slickGenerateTask = {
    (sourceManaged in Compile, dependencyClasspath in Compile, runner in Compile, streams) map { (dir, cp, r, s) =>
      val dbName = "dbname"
      val userName = "user"
      val password = "password"
      val url = s"jdbc:mysql://server:port/$dbName" 
      val jdbcDriver = "com.mysql.jdbc.Driver"
      val slickDriver = "scala.slick.driver.MySQLDriver"
      val targetPackageName = "models"
      val outputDir = (dir / dbName).getPath // place generated files in sbt's managed sources folder
      val fname = outputDir + s"/$targetPackageName/Tables.scala"
      println(s"\nauto-generating slick source for database schema at $url...")
      println(s"output source file file: file://$fname\n")
      r.run("scala.slick.codegen.SourceCodeGenerator", cp.files, Array(slickDriver, jdbcDriver, url, outputDir, targetPackageName, userName, password), s.log)
      Seq(file(fname))
    }
}

任务的代码本身并不是很令人兴奋。它只需要创建一个自动生成的 scala 源文件。问题是，sbt 启动正常，但是这个新任务显然 not 被 sbt 识别，并且不能在 sbt 提示符下运行。我对任务定义的:= 语法也不太满意。现有的文档令人困惑。

如何使这个新任务在 sbt 提示符下可用？

Answer 1

这行得通

libraryDependencies += "com.typesafe.slick" %% "slick-codegen" % "2.1.0"

lazy val slickGenerate = taskKey[Seq[File]]("slick code generation")

slickGenerate := {
  val dbName = "dbname"
  val userName = "user"
  val password = "password"
  val url = s"jdbc:mysql://server:port/$dbName"
  val jdbcDriver = "com.mysql.jdbc.Driver"
  val slickDriver = "scala.slick.driver.MySQLDriver"
  val targetPackageName = "models"
  val outputDir = ((sourceManaged in Compile).value / dbName).getPath // place generated files in sbt's managed sources folder
  val fname = outputDir + s"/$targetPackageName/Tables.scala"
  println(s"\nauto-generating slick source for database schema at $url...")
  println(s"output source file file: file://$fname\n")
  (runner in Compile).value.run("scala.slick.codegen.SourceCodeGenerator", (dependencyClasspath in Compile).value.files, Array(slickDriver, jdbcDriver, url, outputDir, targetPackageName, userName, password), streams.value.log)
  Seq(file(fname))
}

在sbt 0.13.x 中，您不需要所有这些blabla map sameblabla 样板。只需按原样访问值(runner in Compile).value - 宏将为您做所有其他事情。

> slickGenerate
[info] Updating {file:/Users/user/slick/}slick...
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[info] Done updating.

auto-generating slick source for database schema at jdbc:mysql://server:port/dbname...
output source file file: file:///Users/user/slick/target/scala-2.10/src_managed/main/dbname/models/Tables.scala

> help slickGenerate
slick code generation

---

谈论<<= - 你的TaskKey 不正确，见定义：

def apply[T](label : scala.Predef.String, description : scala.Predef.String // not description

所以，旧定义 <<= 使用“生成 slick 代码”作为标签，而新的 := 使用代码给定的命令名称（新样式），因此它使用您的“生成 slick 代码”作为博士。这看起来很奇怪且不一致，但这是事实，部分原因是向后兼容。

所以，正确的旧式版本是：

import sbt.Keys._

lazy val slickGenerate = TaskKey[Seq[File]]("slick-generate", "generate slick code")

slickGenerate <<= slickGenerateTask

def slickGenerateTask =
  (sourceManaged in Compile, dependencyClasspath in Compile, runner in Compile, streams) map { (dir, cp, r, s) =>
    ...
  }

它的工作方式与以前相同。请注意，您必须使用“slickGenerate”，而不是“slick-generate”，最后一个不适用于“help”命令。

顺便说一句，您现在正在使用 Bare build definition - 您可能想要切换到 Multi-project .sbt definition，因为它是 sbt 文档 see also 推荐的。