how do you remove duplicate values ​​from your gallery?

[MelvinGRM]

Hi,

I made a page /app with a shoppingart feature, so people can select items from gallery 1 and they collect them in gallery 2.
It works fines with a simple collect code, but now i want something extra... 

Is it possible that if someone select something from gallery 1, its going to check if there is a same item in gallery 2, and if there is a double item, it wont add them at the gallery but add +1 add the amount field in my gallery (it is a text label) like this: 

left is what i got now.. Right is what i want. 

I hope there are options to make this. Thanks! 

[WiZey · Accepted solution]

Hello @MelvinGRM ,

You can use "IsBlank()" and "LookUp()" to check if an item exist in a gallery.

I believe the following code should help you:

If(IsBlank(LookUp(cart; ID = ThisItem.ID));
  //IsBlank() = TRUE, no item found
  Collect(...);
  //IsBlank() = FALSE, item found
  UpdateIf(cart; ID = ThisItem.ID; {stock: stock+1})
)

Hope this was helpful to you.

[MelvinGRM]

Thanks for your help! 

I made a mistake, but i dont know where... 

I collect the items in gallery 2 with collect MyCollection: Collect(MyCollection;ThisItem);;

I assume i have to paste the code at the sellect button of Gallery1 

The stock value is named in my SP database AantalUIT and the textfield in gallery 2 for stock  is calling quant.Text

so my code 

If(IsBlank(LookUp(MyCollection; ID = ThisItem.ID));
  //IsBlank() = TRUE, no item found
  Collect(...);
  //IsBlank() = FALSE, item found
  UpdateIf(MyCollection; ID = ThisItem.ID; {AantalUIT: stock+1})
)

What did i miss? 

Thanks! 

[WiZey]

Sorry, I'm not sure I understand your issue here. Could you clarify what is not working or what you're not understanding please?

You're saying your cart is stored in a SharePoint list and not in a local collection? 

[MelvinGRM]

Excuse me, ignore the last message. 

The code worked, it adds the item at the gallery, and if it exist, it doesnt add it to the gallery. 

unfortunately it wont add up the stock if i add the same item. It doesnt give an error, code seems fine but i think i miss something.. 

the code: 

If(IsBlank(LookUp(MyCollection; ID = ThisItem.ID));
//IsBlank() = TRUE, no item found
Collect(MyCollection;ThisItem);
//IsBlank() = FALSE, item found
UpdateIf(MyCollection; ID = ThisItem.ID; {Aantal: quant+1})
)

The name of my textfield in the gallery is 'quant' and in the collection the column name is 'Aantal' what is going wrong? Do i need to change my textfield to something else? 

The default of my 'quant field': 

 

Thanks! 

[WiZey]

I believe you need to:

1. Change the label "Default" property to "Text(ThisItem.Aantal)". Your label must show the value of the record's stock, giving it a constant won't help it change.

2. Change the "UpdateIf()" to this:

UpdateIf(MyCollection; ID = ThisItem.ID; {Aantal: ThisItem.Aantal+1})

I think I remember PowerApps automatically converting any text to a zero-value number when used through any patch. To fix it you want to give it the numerical value of the current stock, which is stored in the "Aantal" property of the item you're updating.