Extending the Alfresco Workflow Javascript API
As I was testing the functionality of the user based workflow status reporting API that I posted about recently, I discovered that the Javascript API for workflow in Alfresco only enabled viewing workflow related information for the authenticating user. I however would like to enable monitoring by other users who are either administrators or members of a designated group, such as a “Managers” group of users who will monitor workflow statistics. Fortunately, there is a convenient way to handle this thanks to the magic of the Spring Framework (upon which Alfresco is built).
As described on the wiki, you can add custom Javascript APIs that are backed by Java implementations. In fact, it is via this mechanism that the documented Javascript API is exposed. But for our workflow status reporting scenario, we want to replace the implementation of the exposed “workflow” object with an implementation that allows for our new authorization requirement. Therefore we need to find where the current “workflow” object is configured. A simple grep command revealed that this object (along with all of the others) is configured via the script-services-context.xml Spring configuration file, which has the following bean entry for workflow:
<bean id="workflowScript" parent="baseJavaScriptExtension"
class="org.alfresco.repo.workflow.jscript.WorkflowManager">
<property name="extensionName">
<value>workflow</value>
</property>
<property name="serviceRegistry">
<ref bean="ServiceRegistry"/>
</property>
</bean>
Ideally, we would want to have all of the current capabilities that the WorkflowManager class already implements plus whatever our extension class would add to it via the ‘workflow’ object (including handling for our new authorization requirement in this case). For some reason though, which I chose not to investigate thoroughly, extending an existing class intended for exposure via Javascript isn’t working the way I would have expected (see here for the JIRA report I filed about it). Only the new public methods in my class were being exposed, despite the extension of the existing WorkflowManager class.
Since it’s not terribly critical though, we’ll just build a new class and expose a new object via Javascript. We’ll call it WorkflowStatusManager and configure it via Spring as follows:
<bean id="workflowScript" parent="baseJavaScriptExtension"
class="org.alfresco.repo.workflow.jscript.WorkflowStatusManager">
<property name="extensionName">
<value>workflowstatus</value>
</property>
<property name="serviceRegistry">
<ref bean="ServiceRegistry"/>
</property>
</bean>
Now we’re free to add parameterized accessors for assigned tasks and completed tasks (where the parameter will be the user authority for which to obtain results for). As you can see, this class will have a reference to the ServiceRegistry from the Alfresco Java API, which can be used to gain access to a variety of services, including the WorkflowService which will be used in this case.
One addition that I’m considering adding into the Spring configuration would be a property to set the name(s) of the group(s) that should have access to other users’ workflow data. If you have ideas for other workflow status reporting capabilities to expose to Javascript, please share!
