How to use “If” and “Switch” widgets in OutSystems to display UI elements conditionally?

Using "If" and "Switch" Widgets in OutSystems for Conditional UI Display

 

This guide provides a comprehensive step-by-step process on how to leverage the "If" and "Switch" widgets in OutSystems to conditionally display user interface elements. These tools are essential for creating dynamic and responsive applications that cater to various user interactions and data states.

 

Prerequisites

 

• An active OutSystems account with an application set up in the OutSystems Service Studio.
• Basic understanding of OutSystems architecture, including the structure of screens, variables, and expressions.
• Familiarity with basic logical and conditional expressions used in programming.

 

Understanding "If" and "Switch" Widgets

 

• The "If" widget is used to conditionally display content based on a boolean expression or condition being true or false.
• The "Switch" widget works like a multi-conditional statement allowing different content to be displayed based on the value of a given expression.

 

Implementing the "If" Widget

 

• Open the OutSystems Service Studio and navigate to the screen where you want to implement conditional UI elements.
• From the Widgets Toolbox, drag and drop the "If" widget onto your screen where you want the content to conditionally appear.
• Define the condition: In the properties pane for the "If" widget, specify a boolean expression in the Condition property. For example, User.isLoggedIn or OrderStatus = "Completed". The expression should evaluate to true or false.
• Within the "If" widget, two placeholders are present: TrueBranch and FalseBranch.
• In the TrueBranch, place the elements you want displayed if the condition is true.
• In the FalseBranch, place elements or leave blank if you prefer nothing to be shown when the condition is false.

 

Implementing the "Switch" Widget

 

• From the Widgets Toolbox, drag and drop the "Switch" widget onto your screen where you want to display variable content based on different conditions.
• Specify the Expression: Select the widget and go to its properties pane to define the expression that will be evaluated. The expression should resolve to a specific value like a string or number, which will dictate which content block should be shown.
• Add and Define Cases: Within the Switch widget, add cases corresponding to different possible values of the expression.
• For example, if you are switching based on a PaymentStatus, you might have cases for "Pending", "Completed", and "Failed".
• Add the content inside each case block that should be visible when the corresponding value is present.
• Default Case: Implement a default case if desired, to handle scenarios where the expression doesn’t match any defined case.

 

Integrating with Variables and Data

 

• Use local or session variables to store the state or data that will inform your conditions. These might include boolean flags, status indicators, or user roles.
• Bind these variables in the "If" and "Switch" widget properties to dynamically control the content display as users interact with your application or data changes.
• Ensure your logic expressions consider all possible states of the data to prevent any unexpected behavior or UI display issues.

 

Testing and Debugging

 

• Use the preview feature to test the behavior of your "If" and "Switch" widgets during various states of the application.
• Check all paths in both the "If" and "Switch" conditions to ensure they display the correct UI elements as intended.
• Debug any issues by examining the values and conditions used in your expressions; verify that your logic captures all possible scenarios intended for the application.

 

By following these steps, you'll be able to harness the full potential of the "If" and "Switch" widgets within OutSystems to create dynamic and responsive UIs that adapt based on user actions and data states. Use these widgets to simplify control flow and enhance the user experience of your application.