Order of running the "OnSelect" and "OnChange" triggers

Like (0) Share

Report

Posted on 5 Dec 2022 12:54:31 by Jean-Philippevb

Hi,

I'm trying to create a power app in which i have a questionnaire, with possibility to add a picture if a specific value is selected.

I'm Using a Form, and due to Lay-out limitations i can not have the capture picture together in the "Edit Form" Control.

So in case a picture needs to be taken, the current form will be submitted. and in the next screen the picture will be added. After this the user will be returned to the first screen.

in order to reduce the amount of clicks, i use a slicer (in below example called Req02) to enter the values. with a minimum value of 1, and a maximum value of 5. I also would like to change the Fill color of the DataCard in case the question was answered in a previous screen. (this to make it clear to the user which questions he already has answered.)

For this i use in the "Fill" section of the datacard below function

If(ReqVal02=Blank(),

RGBA(0,0,0,0),

RGBA(226, 250, 230, 0.7))

Via the "OnChange" i would fill in the Variable

Set(ReqVal02,Req02.Value)

But because the use of the Slicer: at the moment it will submit the form (to take the picture), it will select automatically the lowest Value, and thus it will always change the 'blank()' Value of the field even i the user didn't change them. So All questions will be marked as green (Value 1).

I tried to fix this by using the "OnChange" property of the slicer: i was hoping to block this off, So it would only register "manual" changes to the slicer:

"OnSelect":

UpdateContext({OnSel02: 1})

"OnChange"

If(OnSel02=1,

Set(ReqVal02,Req02.Value);UpdateContext({OnSel02: 0}),

Set(ReqVal02,Blank()))

"Default"

If(ReqVal02=Blank(),1,ReqVal02)

But it seems the "On Change" is triggered before the "OnSelect", so with this setup it is not possible to change the value of the slicer at all.

I have the feeling i'm over complicating it, though i don't see much alternatives now (using a dropdown would make it possible, though the user experience would not be the same).

Any advice you can give me?

Categories:

Using Apps Using Formulas

All responses (3)

Answers (1)

cha_cha 4,932 Moderator on 05 Dec 2022 at 14:42:54

Like (1)

Report

Re: Order of running the "OnSelect" and "OnChange" triggers

Hi,

Happy that you got it sorted. You should mark your response as the answer as maybe someone might stumble on the same issue in the future.
Verified answer

Jean-Philippevb 84 on 05 Dec 2022 at 14:40:22

Like (1)

Report

Re: Order of running the "OnSelect" and "OnChange" triggers

Hi Cha_Cha,

I found the solution:
Via the "OnChange" i would fill in the Variable
Set(ReqVal02,Req02.Value)
"OnSelect":
UpdateContext({OnSel02: 1})
and with the OnVisible parameter of the Screen i put:
If(OnSel02<>1,Set(ReqVal02,Blank()));

so i'm blanking out the Values in case the values had not been changed manually. (which allowed me to keep using the slider).
The radio control could have worked, to the feeling of it is different.

Regarding the delegation warning, i did follow the tips and tricks from Reza (see minute 7:10), so i'm filtering in my data as much as possible on validated fields, but in order to get the value of a specific record i understand i Best use the "first()" instead of the Lookup function, This did fix the delegation warning now.

For the tabs, i'm using it in other apps, and will definitely do it also in the monthly audit form (to be added later).

Kind Regards,
Jean-Philippe
cha_cha 4,932 Moderator on 05 Dec 2022 at 13:29:01

Like (0)

Report
Re: Order of running the "OnSelect" and "OnChange" triggers

Hello @Jean-Philippevb

UI-wise, use a Radio control instead of a slider. This makes it easy for users to select the option they want navigating from 1 to 5 every time.
As for your case, if you want to stay with Slider, use only the OnChange
I did a short demo for both: https://youtu.be/XuY7PelXtiM

Advice for your app:
Learn about the use of Collections to avoid those delegation warnings. ⚠️
https://www.youtube.com/watch?v=ipzIWfHVhDc&ab_channel=AprilDunnam
Learn about tab so you can keep on using one screen for a long form.
https://www.youtube.com/watch?v=KjUJZr5Vn_Y&ab_channel=RezaDorrani
✔️
Just in case my response helped you solve your problem, please mark/accept this as a SOLUTION. This helps community members if they experience a similar issue in the future.

🔗
🕸bistek.space 🐦 @cha_bistek 📺 @BisTekSpace