Allow to define outlinkTarget at layer level

umap/static/umap/js/umap.features.js

@@ -57,8 +57,8 @@ L.U.FeatureMixin = {
 
   view: function (e) {
     if (this.map.editEnabled) return
-    const outlink = this.properties._umap_options.outlink,
-      target = this.properties._umap_options.outlinkTarget
+    const outlink = this.getOption('outlink'),
+      target = this.getOption('outlinkTarget')
     if (outlink) {
       switch (target) {
         case 'self':

umap/static/umap/js/umap.layer.js

@@ -862,6 +862,7 @@ L.U.DataLayer = L.Evented.extend({
       'options.showLabel',
       'options.labelDirection',
       'options.labelInteractive',
+      'options.outlinkTarget',
     ]
     builder = new L.U.FormBuilder(this, popupFields, { callback: redrawCallback })
     const popupFieldset = L.DomUtil.createFieldset(