Oracle JET(OJET) Interview Questions and Answers

Ques 1. What is Oracle JET (OJET)?

Oracle JET is targeted at JavaScript developers working on client-side applications. It's a collection of open source JavaScript libraries (Preact or Knockout based architectures) along with a set of Oracle contributed JavaScript libraries that make it as simple and efficient as possible to build applications that consume and interact with Oracle products and services, especially Oracle Cloud services.

Ques 2. What are the architectures Oracle JET(OJET) supports?

As of March, 2023, there are two architecture OJET supports:

• Virtual DOM Architecture
• MVVM Architecture

Ques 3. What is Virtual DOM Architecture in OJET?

It is Preact and TypeScript based architecture. It builds app using the latest React/Preact concepts.

Ques 4. What is MVVM architecture?

It is knockout based architecture. In this architecutre, the code is using JavaScript or TypeScript.

Ques 5. What are the different collections OJET has?

List of different collections under OJET:

• Data Grid
• Indexer
• List Item Layout
• List View
• Paging Control
• Refresher (Touch)
• Row Expander
• Selector
• Stream List
• Swipe Actions (Touch)
• Table
• Tree View
• Use Cases
• Waterfall Layout

Ques 6. What are the different controls are available under OJET?

List of the different controls are available under OJET:

• Avatar
• Badge
• Buttons
• Conveyor Belt
• File Picker
• Film Strip
• Image
• Menus
• Messages
• Progress
• Tags
• Toolbar
• Train

Ques 7. What are the different forms are available under OJET?

List of the different forms are available under OJET:

• Checkboxset
• Color Palette
• Color Spectrum
• Form Layout
• Input DateTime
• Input Number
• Input Password
• Input Search
• Input Text
• Label
• Label Value
• Radioset
• Select & Combobox
• Slider
• Switch
• Text Area
• User Assistance
• Validation

Ques 8. What are the different Frameworks are available under OJET?

List of the different Frameworks are available under OJET:

• Animation
• Binding and Control Flow
• Busy Context
• CSS Utilities
• CSS Variables
• Common Model
• Core Router
• Data Provider
• Deferred Rendering
• Module
• Responsive Behaviors
• Switcher
• Web Components

Ques 9. What are the different Layout and Navigations are available under OJET?

List of the different Layout and Navigations are available under OJET:

Accordion

Action Card

Dialog

Drawer

Flex Layout

Grid

Masonry Layout

Navigation List

Panel

Popup

Tab Bar

Collapsible

Ques 10. What are the different Root Hiddens are available under OJET?

List of the different Root Hiddens are available under OJET:

• App Shell: Hybrid Mobile
• App Shell: Web
• Data Grid
• Form Controls in Collections
• Hidden Data Grid
• Icon Circle
• List
• Messages
• Offcanvas
• Paging Control (Anti Patterns)
• Panel
• Progress
• Responsive Layout
• Select One Spectra

Ques 11. What are the different Visualization components are available under OJET?

List of the different Visualization components are available under OJET:

• Chart
• Diagram
• Gantt
• Gauge
• Legend
• NBox
• PictoChart
• Sunburst
• Tag Cloud
• Thematic Map
• Timeline
• Treemap
• Use Cases

Ques 12. What are the needs OJET fulfills?

Oracle JET is designed to meet the following app needs:

• Add interactivity to an existing page.

• Create a new end-to-end client-side web app using JavaScript, HTML5, CSS, and best practices for responsive design.

Ques 13. What do you need to know to learn OJET?

To begin using Oracle JET, you do not need more than the basics of JavaScript, HTML, and CSS. Many developers learn about these related technologies in the process of learning Oracle JET.

Ques 14. What are the Oracle JET (OJET) features?

Oracle JET features include:

• Messaging and event services for both Model and View layers

• Validation framework that provides UI element and component validation and data converters

• Caching services at the Model layer for performance optimization of pagination and virtual scrolling

• Filtering and sorting services provided at the Model layer

• Connection to data sources through Web services, such as Representational State Transfer (REST) or WebSocket

• Management of URL and browser history using Oracle JET CoreRouter and oj-module components

• Integrated authorization through OAuth 2.0 for data models retrieved from REST Services

• Resource management provided by RequireJS

• API compatibility with Backbone.js Model, Collection, and Events classes, except for Backbone.js Underscore methods.

• JavaScript logging

• Popup UI handling

Ques 15. How to start a Web App in Oracle JET (OJET)?

Use the Oracle JET command-line interface (CLI) to scaffold an app that contains a blank template or one pre-configured Starter Template with a basic layout, navigation bar, or navigation drawer. Each Starter Template is optimized for responsive web apps. Additionally, Starter Templates support TypeScript development should you wish to create your app in TypeScript. After scaffolding, you can modify the app as needed.

1) At a command prompt, enter ojet create with optional arguments to create the Oracle JET app and scaffolding.

ojet create [directory]
            [--template={template-name:[web]|template-url|template-file}] 
            [--typescript]
            [--use-global-tooling]
            [--help]

For example, the following command creates a web app in the my-web-app directory using the web version of the navbar template:

ojet create my-web-app --template=navbar

To scaffold the web app using the same Starter Template but with support for TypeScript version 4.8.4 development, add the --typescript argument to the command:

ojet create my-web-app --template=navbar --typescript

To scaffold the web app that will use the globally-installed @oracle/oraclejet-tooling rather than install it locally in the app directory, enter the following command:

ojet create my-web-app --use-global-tooling 

2) Wait for confirmation.

Ques 16. How to serve a Web App in Oracle JET (OJET)?

Use ojet serve to run your web app in a local web server for testing and debugging. By default, the Oracle JET live reload option is enabled which lets you make changes to your app code that are immediately reflected in the browser.

At a terminal prompt, change to the app’s root directory and use the ojet serve command with optional arguments to launch the app.

ojet serve [--server-port=server-port-number --livereload-port=live-reload-port-number
            --livereload
            --sass
            --build
            --cssvars=enabled|disabled
            --theme=themename --themes=theme1,theme2,...
            --server-only
           ]

Ques 17. What are the different Oracle JET (OJET) commands?

• ojet build (component|pack)
• ojet (build|serve) --theme=<themeName>
• ojet package (component|pack)
• ojet publish (component|pack)
• ojet add (theming|platform|plugins|sass|pwa)
• ojet create theme <themeName> --basetheme=(stable|redwood)

Ques 18. What are the charts in Oracle JET(OJET)?

Charts show relationships among data and display values as lines, bars, and points within areas defined by one or more axes.

Ques 19. What is Line chart in Oracle JET (OJET)?

The Line chart displays series of data whose values are represented by lines.

Use to compare items over the same time.

Charts require data for at least two points for each member in a group. For example, a line chart over months requires at least two months. Typically a line of a specific color is associated with each group of data such as the Americas, Europe, and Asia.

Lines should not be stacked which can obscure data. To display stacked data, use area or line with area charts.