feat(modeling): validate + create unique ids

This adds id logging + validation to the Modeler. As a result the
modeler will throw hard exeptions on colliding id mappings and may
generated unique ids.

Related to bpmn-io/bpmn-js#92

lib/Modeler.js

@@ -1,6 +1,9 @@
 'use strict';
 
-var Diagram = require('diagram-js');
+var Diagram = require('diagram-js'),
+    BpmnModdle = require('bpmn-moddle'),
+    IdSupport = require('bpmn-moddle/lib/id-support'),
+    Ids = require('ids');
 
 var Viewer = require('./Viewer');
 
@@ -41,6 +44,13 @@ Modeler.prototype.createDiagram = function(done) {
   return this.importXML(initialDiagram, done);
 };
 
+Modeler.prototype.createModdle = function() {
+  var moddle = new BpmnModdle();
+
+  IdSupport.extend(moddle, new Ids());
+
+  return moddle;
+};
 
 // modules the modeler is composed of
 Modeler.prototype._modules = Modeler.prototype._modules.concat([

lib/features/modeling/BpmnFactory.js

@@ -5,7 +5,6 @@ var _ = require('lodash');
 
 function BpmnFactory(moddle) {
   this._model = moddle;
-  this._uuid = 1;
 }
 
 BpmnFactory.$inject = [ 'moddle' ];
@@ -23,7 +22,7 @@ BpmnFactory.prototype._needsId = function(element) {
 
 BpmnFactory.prototype._ensureId = function(element) {
   if (!element.id && this._needsId(element)) {
-    element.id = '' + (++this._uuid);
+    element.id = this._model.ids.next(element);
   }
 };
 

package.json

@@ -59,6 +59,7 @@
     "jquery": "~2.1.0",
     "jquery-mousewheel": "~3.1.11",
     "lodash": "~2.4.0",
-    "object-refs": "^0.1.0"
+    "object-refs": "^0.1.0",
+    "ids": "0.0.3"
   }
 }

test/TestHelper.js

@@ -1,7 +1,7 @@
 'use strict';
 
 var _ = require('lodash');
-var BpmnJS = require('../');
+var BpmnJS = require('../lib/Modeler');
 
 // enhance jasmine with test container API
 require('jasmine-test-container-support').extend(jasmine);

test/fixtures/bpmn/draw/task-types.bpmn

@@ -4,7 +4,7 @@
              xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              expressionLanguage="http://www.w3.org/1999/XPath"
-             id="task-types"
+             id="task-types-diagram"
              typeLanguage="http://www.w3.org/2001/XMLSchema"
              xsi:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL http://www.omg.org/spec/BPMN/2.0/20100501/BPMN20.xsd">
     <process id="task-types" isClosed="false" isExecutable="false" processType="None">