feat(modeling): add message flow modeling

Related to #199
Closes #201

lib/features/modeling/ModelingUtil.js

@@ -0,0 +1,56 @@
+'use strict';
+
+var find = require('lodash/collection/find');
+
+
+function getParents(element) {
+
+  var parents = [];
+
+  while (element) {
+    element = element.parent;
+
+    if (element) {
+      parents.push(element);
+    }
+  }
+
+  return parents;
+}
+
+module.exports.getParents = getParents;
+
+
+function getSharedParent(a, b) {
+
+  var parentsA = getParents(a),
+      parentsB = getParents(b);
+
+  return find(parentsA, function(parent) {
+    return parentsB.indexOf(parent) !== -1;
+  });
+}
+
+module.exports.getSharedParent = getSharedParent;
+
+/**
+ * Is an element of the given BPMN type?
+ *
+ * @param  {djs.model.Base|ModdleElement} element
+ * @param  {String} type
+ * @return {Boolean}
+ */
+function is(element, type) {
+  var bo = getBusinessObject(element);
+
+  return bo && bo.$instanceOf(type);
+}
+
+module.exports.is = is;
+
+
+function getBusinessObject(element) {
+  return (element && element.businessObject) || element;
+}
+
+module.exports.getBusinessObject = getBusinessObject;