Creating Applications Using SAP Build Apps

Objectives

After completing this lesson, you will be able to:

Identify the three parts of any application
Build the three parts of application

The Three Parts of Most Apps

Application development structure and design have evolved over several decades to create a common set of areas in which we think about dividing the process and work to create an app.

User interface (UI), logic, and data are the most important areas to think about while starting your app-building learning journey and then planning how to build your app.

The following video explains application development structure and design:

The UI

When you build the user interface, you decide how the user will interact with the application. For example, will they type in data, select data from a list, see a hierarchical list of data, scroll a long list or thumb through pages of data, use radio buttons or toggle buttons.

You must also decide how these components will be organized on the page or whether you will have multiple pages.

Finally, for each component you decide to add to your app, you must configure it:

What is the size, color, or position of that component?
From where will the component get whatever data to display? For example, the text on a button could be static, or it can change and come from a variable.

Data Usage

Almost no application can work without some amount of data. Even a game, which often has no vital long-term stored information, must store user history and leaderboards, and during the playing must keep track of the current state of the game.

Particularly for applications you build with SAP Build Apps in SAP BTP, your data will include data from SAP systems. In addition, you may get information from publicly available and external APIs, such as weather, calendars, social media feeds and more.

In the app, you must specify what data you want to import, and provide connection details for that data.

Usage of the Logic

Finally, the logic determines how the application behaves given changes in the data or actions by the user.

The central place to create logic is in the logic pane, where you create a flow of actions triggered by an event, such as:

User chooses a button.
The value of a variable changes.
A page opens.

For the actions, SAP Build Apps provides a set of flow functions that perform actions such as:

Display a message.
Call an API to retrieve data.
Open a page.
Change the value of a variable.
Open a device's camera (or other native mobile phone action).

Visual cloud functions

Logic can also be written on the server, so the front-end app must call the backend to execute the logic and return some data.

Building the logic on the server comes with multiple benefits. Some potential benefits of this approach include improved security, code reuse, and improved performance.

Summary

Applications are generally made up of 3 parts: User interface (UI), logic, and data. You may want to consider the design of each of these separately as you design your application and before you start building your app.

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