August 2023

25 August 2023

Real time communication between Apps and attended robots

You asked, we listened: now your app responds instantly to user input. To make this happen, build your workflow using two new UiPath^® Studio activities - App Request Trigger and Handle Apps Request - and the new UiPath^® Apps rule - Trigger Workflow.

App Request Trigger and Handle Apps Request activities are included in a dedicated Studio template called Apps-Workflow communication.

The Trigger Workflow rule instantly passes on data you input to the process, then instantly updates the app UI with the output received from the process.

Working with this combo (activities + rule) facilitates instant communication between UiPath^® Apps and an attended robot, eliminating the traditional delay in process start-up. Therefore, initiating a process from your app keeps the communication channel open for rapid back-and-forth until you close the Apps session.

18 August 2023

Apps and VB expressions

"Develop et impera" with the latest update to UiPath^® Apps: VB expressions.

In UiPath^® Apps, you can now use VB expressions (lambdas) to bind control values to data and to transform data, as is also the case of the UiPath^® Studio family. You can create dynamic and responsive user interfaces that can react to user input in real time. If you've used our existing expression language, this approach should be familiar to you, with the added benefit of having the full power of VB.

To use the new capability, simply select the VB as the expression language when creating a new app. The existing expression language is called Legacy, and you can continue to use it until you gain full trust in the efficiency of VB expressions.

Although you can continue to use the Legacy expression language to design your app, we recommend transitioning to VB, and here are some top benefits of doing so:

• Unparalleled customization: With VB's robust and versatile set of tools, you can tailor calculations, functions, and operations to fit your business requirements.

• Enhanced data processing: Deep dive into your datasets and integrate VB expressions into your data processing methods to transform, filter, and validate data with ease.

• Accelerated app development: Leverage the efficiency of VB expressions to speed up your app development, as you can write code more rapidly.

• Superior user experience: Enhance your applications with responsive elements that engage your users by using dynamic and interactive features powered by VB expressions.

Quick start with VB expressions

Want to get a glimpse of what VB expressions can do?

Try this quick example:

1. On the Apps home page, create a new app, and select VB as the expression language.
   
2. Add a Textbox and a Label control to your app.
3. Select the Label control.
4. In the General properties panel, for the Text property, click the "tune" icon . This opens the Expression editor, the editor that makes VB magic happen.
5. Write MainPage.Text.Value. This command instructs the app to take the value your users input in the Textbox control and display it in the Label control at runtime.
6. Preview your app and type something in the Textbox control, then select Enter. Notice how the Label control automatically updates with the same text you typed.
7. Congrats, you have just written your first VB expression in UiPath^® Apps!

Documentation

In terms of documentation, we moved the guide with the legacy expression language to a new Apps publication. The publication is called Legacy - Apps User Guide for Automation Cloud.

This publication contains all updates made to Apps until this day, and it will not be updated anymore. To identify the legacy documentation, look for the "legacy" term in the URL. For example:https://docs.uipath.com/apps/automation-cloud/latest/legacy-user-guide/.

All product updates - new features, improvements, and bug fixes - will be documented in the new publication, which you can access at the existing URL. Therefore, any bookmarks or hyperlinks you were using to access the documentation now point to the guide with the VB expression language.

The How to chapter is work in progress, so thank you for your patience as we revise the examples to use the VB expression language.

Known issue

Issue description

Occasionally, previewing your app displays the following error for controls whose selectedItem property is used in expressions: "'Public Overloads Property SelectedItem As TabularInitClass' has no parameters and its return type cannot be installed."

This behavior occurs after you replace a process, or when you update the version of a process from Orchestrator.

Workaround

To work around the error:

1. Open the Expression editor for those expressions which reference the selectedItem property.
2. Copy the expression which references the selectedItem property.

3. Clear the expression, then click Save to close the Expression editor.

4. Reopen the Expression editor for the same control, paste back in the expression which references the selectedItem property, then click Save.

Another workaround would be:

1. Open the Expression editor for those expressions which reference the selectedItem property.

2. Save the expression without making any changes.

These workarounds should retrigger the expression validation, thus clearing the error.