XML-JSON for Process Central
Process Central is a client application that contains Process Request Forms, Tasks, and Reports. Users of Process Central can start a process, work on tasks, and view reports.
Process Central has the following feature applications that are accessible by selecting an accordion control:
- •Tasks: Displays list of tasks available to the current user. Once a task is selected, the user is presented with the task form and a set of action UI controls to operate on the task (such as claim, save, and complete).
- •Requests: Displays a list of forms that can invoke processes. This list is based on configurations done on the Process Server.
- •Reports: Displays a list of reports.
Component Interaction
Process Central is built on using services exposed by the Process Server. The interaction that occur are shoen in the following figure. Process Central relies primarily on the AvosCentralApi service (for configuration) and the WS-HumanTask (WSHT) taskClient services (for tasks) along with access to resources from the Process Server Catalog using HTTP GETs. The AvosCentralApi is a Process Server system service that exposes a few operations to provide Process Central configuration information based on the current users' role. Process invokes made by the browser (nearly all AJAX requests) are sent to the server using a proxy servlet. This is required to support cross-domain asynchronous requests by the browser in cases where Process Central and Process Server are installed on separate hosts
Login
When a user (with a role of abTaskClient) logs into Process Central, the login code makes an JSON service invoke to the AvosCentralApi service at endpoint /services/JSON/AvosCentralApi. Because the endpoint /services/JSON/AvosCentralApi (in the server) is secured, the application server (for example, Tomcat) intercepts the request to authenticate the user. Once the user is authenticated and authorized (has role abTaskClient), access to the /services/JSON/AvosCentralApi service is granted. Once authenticated, the login operation uses the Process Identity system service
Central Configuration Information
After the user logs in, the main page displays the Tasks, Requests, and Reports sections. For example, in the case of the Requests section the list of available requests organized by category as folders are displayed. The configuration containing the list of requests and categories are obtained from the Process Server using the AvosCentralApi service. The Request configuration (for example) list includes location of the Request HTML form in the server catalog.
Displaying Forms
When a user selects a Request (for example), the browser's JavaScript code makes an HTTP GET request to Process Central to download the HTML form content (for example, project:/path/form.html). If the form is not available locally, Process Central retrieves it from Process Server catalog (using HTTP GET). Before returning the HTML form content to the browser, Process Central may (if translation is available) replace internationalization (I18N) tokens contained in the form after downloading the appropriate I18N bundle from the server's catalog. The $ID suffix in HTML element names, attributes, or in JavaScript are replaced with a unique string (an integer for Request forms, and taskID for Task forms).
Once the HTML form content is loaded by the JavaScript executing the Request UI, the form is inserted into Process Central's UI (for example, the preview area) so that the form is visible and accessible to the end user.
Submitting Forms
Submitting a Request form consists of creating a JSON request with the form data and sending it the appropriate JSON service endpoint to invoke the process.
Caching
Process Central obtains all forms from the Process Server catalog and caches them. If an updated version of a form is redeployed to the server, Process Central will only request it the next time a user logs. During development, you may need to logout and log back in to see the revised form unless you use Process Central in debug mode.
