Interview Questions and Answers

Oracle JET supports the Model-View-ViewModel (MVVM) architectural design pattern.

In MVVM, the Model represents the app data, and the View is the presentation of the data. The ViewModel exposes data from the Model to the view and maintains the app's state.

To begin using Oracle JET, you do not need to understand more than the basics of JavaScript, HTML, and CSS or the third party libraries and technologies that Oracle JET uses. In fact, many developers learn about these related technologies in the process of learning Oracle JET.

Oracle JET supports creating web apps from a command-line interface:

• Before you can create your first Oracle JET web app using the CLI, you must install the prerequisite packages if you haven’t already done so. For details, see Install Oracle JET Tooling.

• Then, use the Oracle JET command-line interface package (ojet-cli) to scaffold a web app containing either a blank template or a complete pre-configured app that you can modify as needed.

• After you have scaffolded the app, use the ojet-cli to build the app, serve it in a local web browser, and create a package ready for deployment.

The app folders contain the app and configuration files that you will modify as needed for your own app.

Oracle JET includes RequireJS, a third party JavaScript library that you can use in your app to load only the Oracle JET libraries you need. Using RequireJS, you can also implement lazy loading of modules or create JavaScript partitions that contain more than one module.

RequireJS is a JavaScript file and module loader that simplifies managing library references and is designed to improve the speed and quality of your code.

RequireJS implements the Asynchronous Module Definition (AMD) API which provides a mechanism for asynchronously loading a module and its dependencies.

Oracle JET's modular organization enables app developers to load a subset of needed features without having to execute require() calls for each referenced object. Each Oracle JET module represents one functional area of the toolkit, and it typically defines more than one JavaScript object.

Oracle JET includes buttons, menus, and container elements to control user actions or display progress against a task. For HTML elements such as simple lists, you can use the standard HTML tags directly on your page, and Oracle JET will apply styling based on the app's chosen theme.

For example, you can use the oj-button element as a standalone element or include in oj-buttonset , oj-menu, and oj-toolbar container elements.

Navigation components such as oj-conveyor-belt, oj-film-strip, and oj-train use visual arrows or dots that the user can select to move backward or forward through data.

To show progress against a task in a horizontal meter, you can use the oj-progress-bar element. To show progress against a task in a circle, you can use the oj-progress-circle element.

Oracle JET includes classes to create responsive form layouts and components that you can add to your form to manage labels, form validation and messaging, input, and selection. The input components also include attributes to mark an input as disabled or read-only when appropriate.

Use the Oracle JET oj-accordian, oj-collapsible, oj-dialog, oj-drawer-*, oj-flex*, oj-masonry-layout, oj-navigation-list, oj-panel, oj-popup, oj-size*, and oj-tab-bar components and patterns to control the initial data display and allow the user to access additional content by expanding sections, selecting tabs, or displaying dialogs and popups.

Area chart in OJET displays series of data whose values are represented by filled-in areas. Areas can be stacked or unstacked. The axis is often labeled with time periods such as months.

The Bar chart displays data as a series of rectangular bars whose lengths are proportional to the data values. Bars display vertically or horizontally and can be stacked or unstacked.

The Box Plot chart displays the minimum, quartiles, median, and maximum values of groups of numerical data. Groups display vertically or horizontally. You can also vary the box width to make the width of the box proportional to the size of the group.

The Bubble chart displays three measures using data markers plotted on a two-dimensional plane. The location of the markers represents the first and second measures, and the size of the data markers represents the proportional values of the third measure.

The combination chart displays series of data whose values are represented by a combination of bars, lines, or filled-in areas.

The Funnel chart visually represents data related to steps in a process as a three-dimensional chart that represents target and actual values, and levels by color. The steps appear as vertical slices across a horizontal cone-shaped section. As the actual value for a given step or slice approaches the quota for that slice, the slice fills.

The Line with Area chart displays series of data whose values are represented as lines with filled-in areas.

Use for visualizing trends in a set of values over time and comparing those values across series.

The Pie chart represents a set of data items as proportions of a total. The data items are displayed as sections of a circle causing the circle to look like a sliced pie.

Use to show relationship of parts to a whole such as how much revenue comes from each product line.

Consider treemaps or sunbursts if you are working with hierarchical data or you want your visual to display two dimensions of data.