Understanding navigation
Many of the apps that you build in Power Apps have more than one screen, so it's essential to understand the two main navigation functions.
Navigate function
The Navigate
function allows users to go (or navigate) from one screen to another. For example, if your app has two screens and you want to give users a way to go to your second screen, you could add a Button
control with the OnSelect
property as follows:
Navigate(Screen2)
With the app in play or preview mode, users select the button and automatically go to Screen2. You could use this formula in an icon (Icon
), such as an arrow, or you could use it in the OnSuccess
property of a form. You can use the Navigate
function anywhere you want to give users the ability to go to a specified screen.
The Navigate
function also allows for an optional visual transition as users go to another screen. You can use the ScreenTransition
parameter to accomplish this transition. A few types of screen transitions are available in Power Apps, and each one provides a slightly different user experience. For example, you could add a Cover
screen transition to the preceding Navigate
formula by entering:
Navigate(Screen2,ScreenTransition.Cover)
If you programmed this screen transition, you would see Screen2 slide in from the right side of the app to cover your screen. This module covers more of this concept in later units.
You can also use Navigate
to set one or more context variables to pass parameters to another screen. That's beyond the scope of this module, but just understand that it's possible to use Navigate
to pass context variables from one screen to another as your users move through the app.
Back function
The second screen navigation function is Back
. The Back
function takes your users to the last screen that they were using. The main difference between Back
and Navigate
is that with Navigate
, you must designate a screen to go to. To work correctly, Back
must include information about the previous screen, or it has no formula context for moving to a different screen.
The Back
function also employs screen transitions. If you use Navigate
with a transition to move a user to a particular screen, the Back
function does the opposite of that transition to return the user to the original screen. It's an optional parameter, so you can specifically designate what type of transition you want to do. We'll cover this concept in the next unit.
Hidden screens
You can add screens to your app without providing any navigation for users to get to those screens. You can use these hidden screens for a purpose such as:
Documentation: Include notes for yourself or another developer on the app.
Template: After you get the look and branding for certain controls, you can paste them to a hidden template screen and then copy them for use on other screens.
Hidden screens are a part of many apps because they provide a quick place for developers to capture important information without allowing users to change anything. They're hidden from your app's users but not from you.
Now that we've reviewed the navigation possibilities in Power Apps, let's cover the syntax and specifics of Navigate
and Back
.