How to set all other dropdown controls in a gallery to a certain value when one of the other dropdowns controls are changed?

[Anonymous]

Hello,

From what I understand so far, within a gallery, all dropdown controls are configured via the same formulas. So when I have an onChange formula set for one of the dropdowns in this gallery, all of the other dropdowns under the same gallery will also have this formula set. 

My issue is I would like to, once any of the dropdowns are set to a number, all other dropdowns under this gallery are set to a certain value, a value of 0 in my instance. However I have not been able to find a way to achieve this.

So to reiterate, if one dropdown value is changed within the gallery, all other dropdown values are set to 0.

Is this possible, and if so, how would I go about achieving this?

Thanks in advance.

[mdevaney]

@AndrewSong_1999
Awhile ago I helped another user set all other toggles in a Gallery to “No” when one toggle is set to “Yes”. Your problem uses dropdowns but the approach you need to take is very similar. If you want to do a simpler task first I would suggest following the instructions in my post to do this successfully with toggles first and then substitute some new code to do it with dropdowns. Once I get to a PC I might be able to redo the example with dropdowns but I thought you might appreciate something to try while you wait.

Here’s a link to that thread I mentioned:
https://powerusers.microsoft.com/t5/Building-Power-Apps-Formerly/Using-Toggle-in-a-Gallery-and-only-...

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[mdevaney]

@Anonymous 

The test I built looks like this.  The user can click on a dropdown to see a selection of numbers from 0-5.  When a non-zero number is picked for an item all other items become 0.

My initial collection called your_datasource_name looks like this.

ClearCollect(
    your_datasource_name,
    {ID:1, Title:"Item #1", Value: 0},
    {ID:2, Title:"Item #2", Value: 0},
    {ID:3, Title:"Item #3", Value: 0},
    {ID:4, Title:"Item #4", Value: 0},
    {ID:5, Title:"Item #5", Value: 0}      
);

Create a new gallery and put this code in the Items property

your_datasource_name

Add a dropdown box to the gallery having these properties.  All you need to change is your_datasource_name and Gallery1 to match your control names.

Default: ThisItem.Value
Items: [0,1,2,3,4,5]

OnChange:
If(
    !(Value(Dropdown1.SelectedText.Value)=0),
    Set(myActiveToggleID,ThisItem.ID);
    ClearCollect(myGalleryIDs,ShowColumns(Gallery1.AllItems,"ID"));
    ForAll(
        myGalleryIDs,
        Patch(
            your_datasource_name,
            LookUp(your_datasource_name,ID=myGalleryIDs[@ID]),
            {Value2: If(myGalleryIDs[@ID]=myActiveToggleID,Dropdown1.Selected.Value,0)}
        )
    )
);
Refresh(your_datasource_name); //only required if you are connecting to the datasource directly instead of using a collection

Hopefully this was worth the wait.

---
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[v-xida-msft]

Hi @Anonymous ,

Do you want to change anyone Dropdown box within your Gallery, then all other Dropdown boxes are set to 0?

Based on the needs that you mentioned, I think a global variable could achieve your needs. I have made a test on my side, please consider take a try with the following workaround:

Set the Items property of the Dropdown box within the Gallery to following:

[0,1,2,3,4,5,6,7,8,9,10]

Set the OnChange property of the Dropdown box within the Gallery to following:

Select(Parent);Set(ChosenValue, Dropdown1.Selected.Value)

Set the Default property of the Dropdown box to following:

If(!ThisItem.IsSelected && !IsBlank(ChosenValue), 0, 2)  // In default, all Dropdown box's default value is 2

Please check the following GIF screenshot for more details:

Please consider take a try with above solution, then check if the issue is solved.

Best regards,

[mdevaney]

@v-xida-msft

The main difference I see between our solutions is that mine will save the changes to the datasource where as your approach does not.  Is my understanding correct here?

[Anonymous]

Hello, this seems to work, but unlike in your GIF, they values change to 0 the moment I press the dropdown button, not when I change the value. I have the formulas on the same properties as you as well, so I'm not sure where I'm going wrong. 

[Anonymous]

Hi mdevaney, out of curiosity how would you refactor your formulas if I don't need to save anything to the data source?

[mdevaney]

@Anonymous 

The solution of @v-xida-msft does work.  It is likely you pasted code into the OnSelect property of the gallery when it should be in the OnChange property instead.

[Anonymous]

The formula is definitely on the onChange property. Not sure what other cause there may be.

[mdevaney]

@Anonymous 

Suggest you do the example by @v-xida-msft from the start one more time.  I have been able to replicate his example.

If you can't get it to work you can give my code above a shot.  It's more code but it also works.  You can use the Collection I provided so you are not writing anything to the datasource.

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