topic How to get Alfresco services in workflow service task in Alfresco Forum

How to get Alfresco services in workflow service task

pnature — Mon, 06 Feb 2017 14:23:41 GMT

Hi,I am new on Alfresco community version 5.2 I need use Alfresco services (NodeService, ContentService, ServiceRegistry) inside class used for workflow service task.I created class but I cannot use Alfresco Services. All methods returns null. What I do wrong?Thanks in advance.My class and reference

Re: How to get Alfresco services in workflow service task

afaust — Mon, 06 Feb 2017 18:01:14 GMT

There are two ways of dealing with Alfresco services in this case.

Configure a bean instance of your delegate in the Spring context files, register it with the Activiti bean registry and use a delegate expression on your task to call the specific bean instead of constructing a new instance.
Use the Activiti bean registry to get a reference to the Alfresco ServiceRegistry and from that obtain all the necessary services.

The limitation on option #2 is that you can only get public services of Alfresco - any components / services not covered by the ServiceRegistry interface are not accessible (if you don't count a dirty trick of using the ServiceRegistry to lookup any bean).

As an example you can get the NodeService this way with option #2:

Map<Object, Object> registeredBeans = Context.getProcessEngineConfiguration().getBeans();
ServiceRegistry registry = (ServiceRegistry)registeredBeans.get(ActivitiConstants.SERVICE_REGISTRY_BEAN_KEY);
NodeService nodeService = registry.getNodeService();‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: How to get Alfresco services in workflow service task

pnature — Tue, 07 Feb 2017 08:56:05 GMT

Thank you for reply.

I am really new in Alfresco and I cannot find information about using Activiti bean registry. What is it? Where is it? Is it configuration file on Alfresco or in project?

I have tried 2. way and I have got contentService but

ContentReader reader = contentService.getReader(docref, ContentModel.PROP_CONTENT);

failed

No authentication provider for net.sf.acegisecurity.providers.UsernamePasswordAuthenticationToken

Re: How to get Alfresco services in workflow service task

upforsin — Thu, 15 Aug 2019 14:45:03 GMT

Could you please elaborate more on the first option?

In service-context.xml we can add new bean:

<bean id="com.example.CreateXML" class="com.example.platformsample.CreateXML" parent="baseJavaDelegate">
  <property name="nodeService" ref="NodeService" />
</bean>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

But how we can "register it with the Activiti bean registry" ? Should we somehow override activitiProcessEngineConfiguration bean?

In the myprocess.bpmn20.xml file we can add:

<serviceTask id="approvedInvoiceScript" name="Test" activiti:class="com.example.platformsample.CreateXML">
  <extensionElements>
    <activiti:field name="nodeService">
      <activiti:expression>${NodeService}</activiti:expression>
    </activiti:field>
  </extensionElements>
</serviceTask>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

An in the CreateXML.java we add:

private NodeService nodeService;
public void setNodeService(NodeService nodeService) {
  this.nodeService = nodeService;
}‍‍‍‍‍‍‍‍

Am I right?

Re: How to get Alfresco services in workflow service task

afaust — Wed, 21 Aug 2019 11:29:25 GMT

In your example, the CreateXML instance will be registered as a bean in the Activiti bean registry simply through the fact that it inherits from the "baseJavaDelegate". You should rename the ID of the bean to something without using dots, as the ID of the bean is what you would use to resolve it, e.g. now it would be ${com.example.CreateXML} in Activiti expressions, which is way confusing and actually problematic as a bean shell expression, since dots have a special meaning as separators for property accessors.

The NodeService would not be available as a bean in your case since only the enclosing instance of CreateXML will be registered as a bean with Activiti. You could of course write some code in CreateXML that overrides the setBeanRegistry method from the BaseJavaDelegate parent class to put whatever you like in the parameter map (the bean registry).