How can I tell the contents of a webjar?

问题:

Let's say I want to use the webjar react-0.12.2 in my Play Framework 2.3 project, and I've depended on it like so:

libraryDependencies ++= Seq(
  "org.webjars" %% "webjars-play" % "2.3.0-2",
  "org.webjars" % "react" % "0.12.2"
)

How do I tell which assets are available in the react webjar?

If I try to access simply "react.js", like in the following example, I get an error due to there being multiple matches for react.js:

<script type='text/javascript' src='@routes.WebJarAssets.at(WebJarAssets.locate("react.js"))'>

回答1:

The easiest way to see the contents of WebJars is on http://www.webjars.org

You can see that there are in fact two instances of react.js in the WebJar. So if you want to use the locator you need to be more specific about the path. But in this case I'd recommend you use the Play asset pipeline that auto-extracts WebJar contents. Docs on that: https://www.playframework.com/documentation/2.3.x/Assets

So your code would be:

<script type='text/javascript' src='@routes.Assets.at("lib/react/react.js")'>

回答2:

In my project, it turned out that the react webjar was installed here (I wonder where it's documented though):

target/web/web-modules/main/webjars/lib/react/