How do I turn a JavaScript object into Map[String,String]?

Question

In index-dev.html I load a local JavaScript file:

<script type="text/javascript" src="map.js"></script>

map.js structurally (not literally) looks like this:

var a2b = {
  "a": "My life closed twice before its close—",
  "b": "It yet remains to see",
  "c": "If Immortality unveil",
  "d": "A third event to me",

  "e": "So huge, so hopeless to conceive",
  "f": "As these that twice befell.",
  "g": "Parting is all we know of heaven,",
  "h": "And all we need of hell.",

  "z": "Emily Dickinson, 1830-1886"
}

I figured out how to load this object into Scala.js:

val a2b = js.Dynamic.global.a2b

Now a2b is of type Dynamic. What I want is Map[String,String].

I tried this:

val a2b = js.Dynamic.global.a2b.asInstanceOf[Map[String,String]]

but that didn't work. What should I do to get a Map[String,String]?

This looks similar: http://stackoverflow.com/questions/31655070/how-to-convert-map-to-json-object-in-scala-js — gknauth, Oct 28 '16 at 17:36

score 7 · Accepted Answer · answered Oct 28 '16 at 17:41

The key thing is that it isn't a Map, which is why it's not working. But it is a js.Dictionary. So use that for your asInstanceOf instead, and if you actually need a Scala Map, use the toMap function on that:

val a2b = js.Dynamic.global.a2b.asInstanceOf[js.Dictionary[String]].toMap

How do I turn a JavaScript object into Map[String,String]?

1 Answers1