Camunda DomElement throws "org.w3c.dom.DOMException: NAMESPACE_ERR"

Camunda 7 Topics Discussion & Questions
1

Hi
I tried to dynamically change the colors of the BPMN elements in my BPMN model using the Java API
(I use SpringBoot , Java 8, camunda-bpm-spring-boot-starter)

I read the DomDocument from the modelInstance and than I try to change the color of some of the elements at runtime, for example

1 BpmnModelInstance modelInstance = repositoryService.getBpmnModelInstance(processDefinitionId);
2 DomDocument document = modelInstance.getDocument();
3 DomElement domElement = document.getElementById(“Start_01”);
4 domElement.setAttribute(“bioc:stroke”, “#34db48”); // green
5 domElement.setAttribute(“bioc:fill”, “#34db48” );

At line 3 I select the BPMNShape

bpmndi:BPMNShape id="Start_01" bpmnElement="Start"

and than I try to set the bioc:stroke/bioc:fill atrributes which contain the colors for the element
My expectation was that after line 4/5 I get the follwong code

bpmndi:BPMNShape id=“Start_01” bpmnElement=“Start” bioc:stroke=“#34db48” bioc:fill=“#34db48”

But line 4 throws an exception

at java.lang.Thread.run(Thread.java:745)
Caused by: org.w3c.dom.DOMException: NAMESPACE_ERR: An attempt is made to create or change an object in a way which is incorrect with regard to namespaces.
at com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.checkDOMNSErr(CoreDocumentImpl.java:2547)
at com.sun.org.apache.xerces.internal.dom.AttrNSImpl.setName(AttrNSImpl.java:117)
at com.sun.org.apache.xerces.internal.dom.AttrNSImpl.(AttrNSImpl.java:78)
at com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.createAttributeNS(CoreDocumentImpl.java:2164)
at com.sun.org.apache.xerces.internal.dom.ElementImpl.setAttributeNS(ElementImpl.java:659)
at org.camunda.bpm.model.xml.impl.instance.DomElementImpl.setAttribute(DomElementImpl.java:244)
at org.camunda.bpm.model.xml.impl.instance.DomElementImpl.setAttribute(DomElementImpl.java:231)
at org.camunda.bpm.model.xml.impl.instance.DomElementImpl.setAttribute(DomElementImpl.java:227)

How can I solve this?
Cheers Roland

2

Hi
I found a solution.

In the class that creates the BPMN document I have to define the correct namespace

this.modelInstance = Bpmn.createEmptyModel();
this.definitions = modelInstance.newInstance(Definitions.class);
definitions.setTargetNamespace(“The Universal Process Orchestrator | Camunda”);
definitions.setAttributeValueNs(“A Namespace Name for xmlns Attributes”, “xmlns:bioc”, “http://bpmn.io/schema/bpmn/biocolor/1.0”);
modelInstance.setDefinitions(definitions);

Than, in the class where I want to change the color-attributes I have to use this namespace

DomElement domElement = document.getElementById(elementKey);
domElement.setAttribute(“http://bpmn.io/schema/bpmn/biocolor/1.0”, “stroke”, “#34db48”);
domElement.setAttribute(“http://bpmn.io/schema/bpmn/biocolor/1.0”, “fill”, “#34db48”);

At runtime, this results in

bpmndi:BPMNShape id=“Start_01” bpmnElement=“Start” bioc:stroke=“#34db48” bioc:fill=“#34db48”