Define allowed dataAttributes as Timeline option

Read from an array of allowed dataAttributes at the timeline level and
write them as data- attributes on the item

lib/timeline/Core.js

@@ -173,7 +173,7 @@ Core.prototype._create = function (container) {
 Core.prototype.setOptions = function (options) {
   if (options) {
     // copy the known options
-    var fields = ['width', 'height', 'minHeight', 'maxHeight', 'autoResize', 'start', 'end', 'orientation', 'clickToUse'];
+    var fields = ['width', 'height', 'minHeight', 'maxHeight', 'autoResize', 'start', 'end', 'orientation', 'clickToUse', 'dataAttributes'];
     util.selectiveExtend(fields, this.options, options);
 
     if ('clickToUse' in options) {

lib/timeline/component/ItemSet.js

@@ -259,7 +259,7 @@ ItemSet.prototype._create = function(){
 ItemSet.prototype.setOptions = function(options) {
   if (options) {
     // copy all options that we know
-    var fields = ['type', 'align', 'orientation', 'padding', 'stack', 'selectable', 'groupOrder'];
+    var fields = ['type', 'align', 'orientation', 'padding', 'stack', 'selectable', 'groupOrder', 'dataAttributes'];
     util.selectiveExtend(fields, this.options, options);
 
     if ('margin' in options) {

lib/timeline/component/item/Item.js

@@ -140,4 +140,24 @@ Item.prototype._repaintDeleteButton = function (anchor) {
   }
 };
 
+/**
+ * Process dataAttributes timeline option and set as data- attributes on dom.content
+ */
+ Item.prototype._attachDataAttributes = function() {
+  
+  if (this.options.dataAttributes && this.options.dataAttributes.length > 0) {
+    
+    var auxiliaryData = Object.keys(this.data);
+
+    for (var i in this.options.dataAttributes) {
+      var c = this.options.dataAttributes[i];
+      if (auxiliaryData.indexOf(c) >= 0) {
+        this.dom.content.setAttribute('data-' + c, this.data[c]);
+      }
+    }
+  }
+
+
+ };
+
 module.exports = Item;

lib/timeline/component/item/ItemBox.js

@@ -132,16 +132,8 @@ ItemBox.prototype.redraw = function() {
     this.dirty = true;
   }
 
-  // set all other fields as data- attributes
-  var auxiliaryData = Object.keys(this.data);
-
-  for (var i in auxiliaryData) {
-    var c = auxiliaryData[i];
-    if (['start', 'end', 'content', 'title', 'id', 'className', 'group', 'type'].indexOf(c) < 0) {
-      dom.content.setAttribute('data-' + c, this.data[c]);
-    }
-  }
 
+  this._attachDataAttributes();
 
 
   // recalculate size

lib/timeline/component/item/ItemPoint.js

@@ -121,15 +121,7 @@ ItemPoint.prototype.redraw = function() {
     this.dirty = true;
   }
 
-  // set all other fields as data- attributes
-  var auxiliaryData = Object.keys(this.data);
-
-  for (var i in auxiliaryData) {
-    var c = auxiliaryData[i];
-    if (['start', 'end', 'content', 'title', 'id', 'className', 'group', 'type'].indexOf(c) < 0) {
-      dom.content.setAttribute('data-' + c, this.data[c]);
-    }
-  }
+  this._attachDataAttributes();
 
   // recalculate size
   if (this.dirty) {

lib/timeline/component/item/ItemRange.js

@@ -115,17 +115,7 @@ ItemRange.prototype.redraw = function() {
     this.dirty = true;
   }
 
-
-  // set all other fields as data- attributes
-  var auxiliaryData = Object.keys(this.data);
-
-  for (var i in auxiliaryData) {
-    var c = auxiliaryData[i];
-    if (['start', 'end', 'content', 'title', 'id', 'className', 'group', 'type'].indexOf(c) < 0) {
-      dom.content.setAttribute('data-' + c, this.data[c]);
-    }
-  }
-
+  this._attachDataAttributes();
 
   // recalculate size
   if (this.dirty) {