Set Control Value/Text OnChange

[audrieg]

Could we please have the ability to set a control value based on the change of another control?

Example:

TEXTBOX1: Enter your HR Code please....

TEXTBOX2: (a hidden text box controlling some IF/THEN statement elsewhere in the app)

TEXTBOX1: OnChange>> Set.TextBox2.Text = This.Text

I understand we use collections and context, but it would be nice to have the option to simply set a value too.

Thank you.

[AndyPennell]

Can't you do:

TEXTBOX2: Text=If(TextBox1.Text="1","a","b")

When Textbox1.Text changes, so will Textbox2.Text.

[audrieg]

Didn't work for me (see screen shot below). In that screen shot I tried your statement as a button click, and the onchange of the trigger text box. Am I missing something?

I understand your expression to mean:

IF Textbox1.Text is equal to 1, then make Textbox2.Text equal to "a"

ELSE (not equal to 1) make Textbox2.text be equal to "b"

I'm really looking for something that is not an "IF" statement - it's a SET statement (irrelevant of any condition) meaning - SET that.value to this.value whenever this.value changes. It makes it very easy to integrate business rules into forms.

Here is my effort at your suggestion - I annotated it so you'd know what I did:

In my last try: I had to modify your expression to include the target input box. In that case, the button worked, and the default works - but it won't change to "a" when the Trigger input box changes.

I have uploaded the file to here:

https://1drv.ms/u/s!ArGMAcQsnkwmcsnhBpQbyF0SsYo

Repro: change Trigger to 1 - the default value should now change to a. (I think PowerApps people have a different definition of the word "default" than I do. LOL

IMO "Default" means the very first value, that is editable in any way you can edit it. - But PowerApps seems to be very "STICKY" on default values for some reason. (FYI: This is a true scenario to SharePoint Apps because all editform fields must use Parent.Default values....so I need to be able to overwrite the default in some cases.)

[SergioGiusti]

Hi did you get anywhere with this?

I have the same query, i have a control getting a dropdown choice list from a sharepoint list, when its value is selected id like to set another controls value dependent on what was chosen.

i.e.

SharePoint list 1

Column 1 - Column 2

ABC           DEF

SharePoint list 2 (my PowerApp)

Column 1 is a lookup to Column 1 in list 1

Column 2 is a text field

If column 1 is selected, if like it to input the value from Column 2 in list 1 into Column 2 in list 2

Hopefully that makes sense.

Thanks

[audrieg]

Yes, I got it to working exactly the way I wanted it to using the UpdateContext function. Just remember that it is contextual for that screen only.

UpdateContext details:

https://powerapps.microsoft.com/en-us/tutorials/function-updatecontext/

[murali · Accepted solution]

@CameronCaudill

PowerApps is driven by a declarative dataflow language. What this means is you tell control properties where to get their values and dataflow takes care of setting values. It's different from imperative languages where you tell objects to do something.

For instance.

If you want TextBox2 to have the same "Text" as TextBox1 i.e. whenever TextBox1's Text changes, change TextBox2's Text, you do the following:

1. Select TextBox2

2. Set it's Text property to TextBox1.Text.

Dataflow takes care of updating TextBox2.Text whenever TextBox1.Text changes.

Hope that clarifies things.

Thanks

Murali

[audrieg]

Yes, I've been doing that and honestly, I'm getting used to the approach more and more each day. 🙂

I was wondering if you have any recommendations on a similar topic: Input Mask approach.

I want to control the format of what my customers can enter into the text box. Do you have any ideas on that point that I can share with others? I've got a couple of workarounds but I'd love your ideas as a SME.

Thank you again!

Audrie

[drbsoftware]

Suppose I have 2 text boxes, Country and Currency.

When I set Country, I want a default Currency to be set, provided no Currency has been set.

But I want the User to be able to override the Currency setting.

Is this possible with the rule engine?  If so, how?

[roknron]

The onSelect property of the button is not setting the value of TxtTrigger.Text.  Just change the onSelect of the button to TxtTrigger.Text = "1", then test the value of TxtTrigger.Text in the onChange property of the next box.  I'm not certain that the onChange event will be fired if you set the value with another control.  The defaut value can be anything you like in your third textbox, but, for you example to work you need to set the Text proprety of the third textbox to TxtReveived.Text.  For your last TxtRecieved.Text value should be reflected as a. 

[sscarcella]

I have 2 choice fields in a SharePoint list that are Yes/No fields.  I want field 2 to have No selected if field 1 is Yes.  I cannot figure out how to do this with updatecontext.  Can you explain what you did.