Loader: support json files where multiline strings are split as string-arrays

src/OpenStreetBrowserLoader.js

@@ -1,4 +1,5 @@
 var OverpassLayer = require('overpass-layer')
+var jsonMultilineStrings = require('./json-multiline-strings')
 
 function OpenStreetBrowserLoader () {
   this.types = {}
@@ -31,6 +32,7 @@ OpenStreetBrowserLoader.prototype.getCategory = function (id, callback) {
     }
 
     var data = JSON.parse(req.responseText)
+    data = jsonMultilineStrings.join(data)
 
     this.getCategoryFromData(id, data, function (err, category) {
       if (category) {

src/json-multiline-strings.js

@@ -0,0 +1,31 @@
+function isStringArray (arr) {
+  if (!Array.isArray(arr)) {
+    return false
+  }
+
+  var nonStringElements = arr.filter(function (x) {
+    return typeof x !== 'string'
+  })
+
+  if (nonStringElements.length) {
+    return false
+  }
+
+  return true
+}
+
+function join (data) {
+  for (var k in data) {
+    if (isStringArray(data[k])) {
+      data[k] = data[k].join('\n')
+    } else if (typeof data[k] === 'object') {
+      data[k] = join(data[k])
+    }
+  }
+
+  return data
+}
+
+module.exports = {
+  join: join
+}