Oracle APEX Radio Group null option fix

APEX 5.1 introduced a template option that transformed radio groups into pill buttons.


I love this concept, it makes for a pleasant UI - an easier target for mouse clicks and finger taps.
I liked it so much I tried to do this myself prior to 5.1.

In 18.2 (fixed in 19.1), there's an issue with the way the null option presents for these radio groups - it's not in the (more...)

Oracle JET – How To Reference JavaScript Module in HTML

I will explain how to reference JavaScript module function in Oracle JET HTML. In previous Oracle JET versions, we were using $root to access parent appController module. Syntax $root looks a bit like magic, it is better to reference module through a predefined variable. I will show you how.

Sample app comes with number converter, which helps to format numeric value. For convenience reasons and better reuse, number formatting function is moved to a separate (more...)

Oracle JET Model ID Attribute

When building Oracle JET Model/Collection structure to render table, you should be careful defining ID attribute. This attribute must have unique values only, if there will be duplicates in ID, then table rows will be rendered incorrectly.

Take as example below structure for Employees REST endpoint. EmployeId attribute provides unique values and it should be defined as ID for JET model:


Let's try and see what happens when non-unique DepartmentId attribute is set for a (more...)

Dynamic tabs with Angular 6+ and ng-bootstrap

One of our Angular applications required the use of dynamic tabs. Since the project already uses ng-bootstrap components and bootstrap for the styling, I decided to use the tabset component from ng-bootstrap.

The tabs needed to fulfil the following requirements:
– A tab can be opened and closed.
– Tabs can display different components depending on the menu item clicked.
– There can only be one open tab for a given component.
– If a (more...)

Oracle Developer Tools – Do They Still Exist?

People are frustrated about @OracleADF @JDeveloper on social media - "ADF boat has no captain", etc. I agree @Oracle is to blame big time for such lame handling of its own Developer Tools stack. @Oracle please wake up and spend some budget on @OracleADF. Read more:

Oracle VBCS - right now this tool gets the most of Oracle focus. Supposed to offer declarative #JavaScript development experience in the Cloud. Not well received by the community. (more...)

Running Oracle JET as Progressive Web App

Progressive Web Apps (PWA) topic is a hot thing in web development these days. Read more about it - Progressive Web Apps. The beauty and power behind PWA - user can install a web app to his mobile device, without going through the app store. This simplifies update process too, when a new version of the app is available, the user will get it straight away, because it is essentially a Web page, wrapped to (more...)

Graceful shutdown of forked workers in Python and JavaScript running in Docker containers

You might encounter a situation where you want to fork a script during execution. For example if the amount of forks is dependent on user input or another specific situation. I encountered such a situation in which I wanted to put load on a service using multiple concurrent processes. In addition, when running in a docker container, only the process with PID=1 receives a SIGTERM signal. If it has terminated, the worker processes receive a (more...)

ADF Faces and Client Side Value with innerHTML

In ADF Faces you can leverage the full power of JavaScript. I will explain how you could assign a value from ADF Faces component to the plain HTML div.

The sample app is available on GitHub repo. It doesn't require DB connection, you can run it straight away in Oracle JDeveloper.

Look into JSF page. I have implemented ADF Faces input component with value change listener. Below this component, there is HTML div with ID (more...)

Run Oracle VBCS Application on Your Own Server

Latest VBCS release brings an option to export VBCS application and run on your own server (or different cloud provider). This is a truly strong step forward for VCBS. Read more about it in Shay Shmeltzer blog post. If you decide to keep running VBCS app within VBCS itself, then you get additional functionality of VBCS Business Services, Oracle Cloud security, etc. out of the box. If you export VBCS application and run on your (more...)

Build it Yourself — Chatbot API with Keras/TensorFlow Model

Is not that complex to build your own chatbot (or assistant, this word is a new trendy term for chatbot) as you may think. Various chatbot platforms are using classification models to recognize user intent. While obviously, you get a strong heads-up when building a chatbot on top of the existing platform, it never hurts to study the background concepts and try to build it yourself. Why not use a similar model yourself. Chatbot implementation (more...)

Hide Pagination if one page results – Oracle APEX

I love this period of development not long after an APEX upgrade, where I discover all these little improvements that will help us out. Stuff that's not quite noteworthy in the wonderful read that is the new features guide (that's not sarcasm. Read it. Now.)

Recently I made an observation regarding a handy new template option, one that hides pagination if there is only one page of records. I've had a bit of jQuery (more...)

Oracle JET Table with Template Slots for Custom Cells

Oracle JET table comes with template slot option. This is helpful to build generic functionality to render custom cell within the table.

In this example, custom cells are used to render dates, amount and risk gauge:


While implementing Oracle JET table it is a best practice to read table column structure from a variable, not to define the entire structure in HTML itself. Property columns refer to the variable. Template called cellTemplate is a default (more...)

Cross Field Form Validation in Oracle JET

JET keeps evolving and in the latest versions  - toolkit provides improved support for form cross-field validation. It is much easier to implement validation than it was before. I will show it in this example.

Example of the data entry form. Validation logic:

- Invoice Date before Payment Due Date and Payment Date
- Payment Due Date before Payment Date


Example when two fields fail validation:


JET provides component called validation group. Form can be (more...)

Search Form in Oracle Visual Builder based on ADF BC REST

Oracle Visual Builder supports ADF BC REST out of the box. Build service connection using "Define by Specification" wizard:


Wizards support ADF as API type. Add describe at the end of the REST URL, this will bring metadata for exposed ADF BC REST service (information about attribute types, etc.):


List of endpoints will be populated automatically. You could select all endpoints to be supported for your connection or select only few:


The most typical (more...)

Oracle Visual Builder 18.4.5 and JET 6 Support

Oracle Visual Builder 18.4.5 comes with very neat and polished UI. Also it brings Oracle JET 6 support (latest JET version to date). Read more about it - New Features in Oracle Visual Builder December Release.

I have upgraded our VBCS instance to 18.4.5:


I was curious how automatic upgrade would work for VBCS app implemented in the previous version (download source code for the upgraded app from my GitHub repo). (more...)

Knockout.js – Updating Single Array Element (Oracle JET)

If you implement tables and using Knockout.js to push data updates from JS to HTML - probably you experience a situation when it doesn't work to push an update for one of the columns. I mean you could replace the whole observable array element - this would cause full row refresh. But visually this doesn't look nice and why to refresh the whole row, if only one (or few) element (-s) from the row must be refreshed.

(more...)

Off Canvas Menu in Oracle VBCS/JET Cloud

These days I'm actively working with VBCS/JET Cloud product from Oracle. The more I work with VBCS the more I like it. VBCS follows similar declarative development concepts as Oracle ADF, this makes it easy to get up to speed with VBCS development. VBCS with declarative JavaScript development approach brings unique solution for JavaScript systems implementation for enterprise.

I will share sample with off canvas menu implementation for VBCS app. Sample is based on step (more...)

Date Format Handling in Oracle JET

Oracle JET comes with out of the box support for date converter, check more about it in cookbook - Date Converter. This makes it very handy to format dates in JavaScript. Here is date picker field example with yyyy-MM-dd format applied:


When button Process is pressed, I take date value from date picker and add one day - result is printed in the log. This is just to test simple date operation in JavaScript.

Date (more...)

Notification Messages in Oracle JET

Let's take a look into cool component available in Oracle JET - notification messages (it is possible to display messages in different ways - inline or overlay. Check more about messages functionality in JET Cookbook example).

This is how notifications messages are showing up, very cool way to send information to the user:


Messages are implemented with oj-messages components. This component accepts observable array of messages to be displayed. We can specify how message (more...)

await in turn by mistake

I really enjoy working with the new async functions but it is really easy to set up a situation where code that could be running in parallel is force to run in sequence. Consider this simple invocation of a javascript function that takes two values returned from other async functions:

   const combination = await combine(await value(1), await value(2));

The problem here is that unless the JS environment does some optimisation for you, the actions contained (more...)