Re: [jbpm-dev] Human Task Module API and DataStructures Proposed changes

Thanks Maciej for the questions. I've included comments between the bullets "Mauricio, couple of questions at the very beginning to understand correctly your proposal: * Q: how does task def service applies to process interactions - when task definition will be deployed? A: I was trying to not think about the process engine for exposing a Human Task Interactions APIs, but I understand your question. Right now inside our HTWorkItems we are calling the taskClient.add method which in fact is doing a deploy and an instantiation of a task based on the WorkItem params map. This parameters map is created based on the userTask defined in a process and its internal data mappings. That's from one side. With the form builder, what can be done right now is to "decorate" a userTask from a business process and define a form based on it. So basically we do something like: pick a process, get all the userTasks and for each task we end up with a TaskForm.def this TaskForm.def can be associated with a TaskDefinition, instead with a TaskInstance, promoting reusability as much as we can. If we have this TaskDefService, we can make both: the WorkItemHandlers and the Form builder to consume the same information and reuse that as much as we can. We can include the process designer in the loop and make the Company Tasks Definitions available for the editor, so the user when want to place a new UserTask inside their process, can choose from a list of presets instead of filling all the mappings, user assignments, presentation details, notifications settings, etc. * Q: delegation service - since that is on task def level - what about sharing this information on concurrent task instances since based on the same definition expressions can be evaluated to different values A: Yes that's the idea. In the static information we can have an expresion, in that case the expresion will be evaluated with the TaskInstance context and the result will be placed in the task instance context, the task def information will not be changed, so it can be safely shared between instances. All the taskDef related structures should contain "templating" information which means something for the company. All the runtime status will be kept in the task instances. Think about TaskDef, DelegationsDef, NotificationDef, as shortcuts for the users to not define everything each time that they want to instantiate a task. * Q:how is this going to be configured - per service or will there be a configuration service as well A: good question, we can add this topic for our board session :) I'm not a CDI expert, but based on what I've being reading, you can provide a default set of services that will be automatically instantiated and injected, and then you can provide alternatives. If the user doesn't want the default settings he can defined the alternatives via a vary basic configuration file. Using CDI qualifiers we can, with a pair of annotations, define which set implementations (1 configuration) do we want for our whole set of services. Would be really nice to see how this is going to be utilized from following perspectives: * Q: process engine - how process engine will interact with human task services A: This should not be a problem of this module, and I think that this can be considered as an integration problem, so it can be fixed with an specialized framework such as switchyard and/or camel. I've being reading about the CDI support for them.. and I think that we can go in that way. The Callbacks/Listener Service is intended to store information about the Task Owners and their interest to be notified about a tasks events. We need to think about this a little bit more, because the Process Engine is not the Task Owner of a TaskInstance that has being created by a business process instance. The business process instance is the owner of that task in that case, so we will need to keep a reference from that process instance inside this service. When I say, reference I mean a business key, an ID, an endpoint or something to be able to notify the interested ones. * Q: task client - how to access tasks and to perform operations on them" A: via the TaskInstanceService, its the same as our TaskClient right now. (but restricted for TaskInstances and TaskInstancesQueries, not add, not Comments, not attachments, not notifications) Cheers On Wed, Jun 27, 2012 at 1:02 PM, Mauricio Salatino <salaboy(a)gmail.com <mailto:salaboy@gmail.com>> wrote: Hi guys, I'm back with more wiki pages. I was thinking about how to improve the Human Task Module and I came back with this wiki page that shows some proposals. The main idea behind the proposal is to modularize as much as we can the features provided by the human task module. I've also included into the proposal the concept of TaskDefinition which will allow us to add a nice integration with the form builder (in modeling and in runtime phases). I'm trying to move towards CDI to leverage all the mechanisms provided by the framework and the fact that exposing CDI beans across different platforms is extremely easy these days. https://community.jboss.org/wiki/HumanTaskAPIAndDataStructuresProposal I understand that the changes proposed in the wiki looks quite heavy, but I do believe that we can fit the current code base into that structure without loosing functionality. The document is showing APIs and Data Structures only. i think that we can assume that all the services implementation will represent simple stateless services which will insert and read information from a database, so architecturally speaking from that perspective the service implementations should be straight forward. I will be filling the Data Structure Sections briefly, but I would like to share the main concepts with you guys to gather feedback, as always. Cheers -- - MyJourney @ http://salaboy.wordpress.com - Co-Founder @ http://www.jugargentina.org - Co-Founder @ http://www.jbug.com.ar - Salatino "Salaboy" Mauricio - -- - MyJourney @ http://salaboy.wordpress.com - Co-Founder @ http://www.jugargentina.org - Co-Founder @ http://www.jbug.com.ar - Salatino "Salaboy" Mauricio - _______________________________________________ jbpm-dev mailing list jbpm-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/jbpm-dev