Sunday, August 12, 2018

Flow Navigation Menu Control in Oracle VBCS

Oracle VBCS allows us to build multiple flows within the application. This is great - this helps to split application logic into different smaller modules. Although VBCS doesn't offer (in the current version) declarative support to build menu structure to navigate between the flows. Luckily this requirement can be achieved in few simple steps, please read John Ceccarelli post - Adding a Navigation Bar to a VBCS Application. I thought to go through instructions listed by John and test it out, today post is based on this. In my next posts I will take a look how to replace navigation bar menu structure with something more advanced, for example - menu slider on the left.

I think VBCS have great potential as JavaScript declarative development IDE. I see many concepts are similar to other Oracle declarative development tools, e.g. Forms, Oracle ADF. VBCS runs Oracle JET, all you build in VBCS is Oracle JET. Oracle takes care upgrading Oracle JET version in VBCS, I have applied recent patch (by click of the button) and latest JET version is available within our VBCS environment:

Coming back to flows in VBCS. We can create as many flows we want. Each flow could be based on one or multiple fragments (HTML/JS modules). Here I have created three flows, each with single fragment:

We can select flow and this will bring us flow diagram, where we could have navigation implementation between flow elements/fragments:

Fragment - this is where UI part is done:

So thats about flows and fragments. For someone with ADF background, this sounds very similar to task flows and fragments. Next we should see how to implement flow navigation, to be able to select flow from the top menu. VBCS application comes with so called shell page. This page is top UI wrapper, which contains application name, logged user info, etc. Here we can implement top level menu, which would navigate through application flows:

There must be default flow, which is displayed once application is loaded. Default flow is set in settings of the shell page. Go to settings and choose default flow, dashboard-flow in my case:

Next we need to add JET component - navigation list to the shell page, to render menu UI. You can do it by drag and drop, but easier is to switch shell page to source view and add navigation list HTML portion manually (you can copy paste it from source code uploaded to GitHub, see link at the end of this post) - highlighted HTML will render menu bar to navigate between flows:

Initially you will notice error related to JET navigation list not recognised, we need to import it. Another error - selection listener is not found, we will implement it.

To import JET navigation list component, go to source implementation of the shell page and add oj-navigation-list in component imports section - this will solve issue with unknown navigation list entry:

To execute action in VBCS, we must create Action Chain. Crete Action Chain within shell page - navigateToPage:

We need input parameter - flow name, which want navigate to. Create variable in Action Chain - currentFlow:

Add action of type Navigate to Action Chain, this will trigger navigation logic:

Go to Action Chain source and add "page": "{{$variables.currentFlow}}" under actions. This will force navigation to the flow, which will be passed through parameter:

Finally we create navigation list selection event (within shell page), this event will trigger action chain created above and pass current flow ID. We must create custom event and its name should match even name defined in JET navigation list in HTML (see above):

Choose to create custom event (it didn't work for me in Chrome, only in Safari browser. VBCS bug?) and provide same name as in navigation list component listener:

Choose our navigation Action Chain to be triggered from this event:

Just a reminder, event is called from navigation list selection:

Event is passing flow ID from currently selected tab item:

On runtime, dashboard flow is loaded by default:

We can switch to Jobs, etc.:

Download exported (runnable only in VBCS) VBCS app from GitHub repo.

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