Updating SharePoint list

[Jyoung]

Hi,

Im pretty new to Powerapps but i have got the hang of some things and have managed to create an App based on fields within a sharepoint list.  

The user will check out these items and place them in a shopping cart and then process the order.  This is an internal system so no actual money gets exchanged.

Im stuck on one thing that i think should be simple.  When the user checks out the shopping cart ( this is a collection) i want to be able to update the existing list with how many items are remaning in stock.  For example, A user want 2 folders and 3 pens.  There is currently 5 of each in stock.  The user adds 2 folders and 3 pens to the cart and checks them out.  I want power apps to go back to the sharepoint list that the data is being read from and deduct 2 folders and 3 pens  so that folders now say 3 and pens say 2.

Can some one point me in the right direction?

Thanks,

Josh

[aprildunnam]

Could you share how your SharePoint list is set up (the columns, sample data, etc)?  

[Jyoung]

Hi Aprildunnam,

Thanks for your reply.  The list is very simple:

Title (which is essentialy the Item Name)

Stock Used

Stock Remaining.

Thanks,

Josh

[aprildunnam]

This would be a good use case for a Flow.  I've did this with one of my PowerApps.  You could follow the directions to Start a Flow from a PowerApp here:

https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/using-logic-flows  

In your PowerApp you'll need to use the ForAll() function to loop through your collection and then run your Flow and pass the parameters to update the list item.  

[Jyoung]

Thanks,

I actually dont know how i would use the flow to do this.. Ive loked at various blogs etc but i cant make sense of it... perhaps i just need a nap.

Without spending too much time could you give me a little but more info?

Thanks 🙂

[aprildunnam · Accepted solution]

So I thought about your use case a little more and I think you could accomplish what you're needing with a simple Patch statement.  I did a quick test on my environment and that seemed to work.  I have a collection of items and I added a submit button with the following function:

ForAll(ShoppingCart,Patch(InventoryTest,First(Filter(InventoryTest, ID in ShoppingCart.ID)),{StockRemaining: StockRemaining - 1},{StockUsed: StockUsed +1}));Clear(ShoppingCart)

So first, I'm using ForAll to loop through all items in my collection.  Then I'm using the Patch statement which lets you add items to SharePoint.  I'm passing in the name of my data source (the SharePoint list) and then I'm using the First and Filter functions to make sure I'm getting the current item to update.  Then I'm taking my stock remaining and subtracting 1 and taking stock used and adding 1.  

I hope this helps!

[Jyoung]

Thanks April,

I think i am closer than ever.  For testing purposes i am using this.

ForAll(ShoppingCart,Patch(Stationary,First(Filter(Stationary, ID in ShoppingCart.ID)),{Used:1}))

However it tells me that ID on the left side of the in operator cannot be converted to a control.  There is no error in the code just a blue dot.

I tried to execute the code but still the list does not get updated.

Any further advice would be much appreciated 🙂

Thanks,

Josh 

[aprildunnam]

Hmmm.  Have you tried using = instead of in?  Is there any way you could share some screenshots on how your app and data source is configured to give me a little more to go on?

[Jyoung]

No problem.

Attached are the screen shots:

I have a sharepoint list called stationary.  Inside that are 4 columns:

 - Item ( Text)

 - Required Stock ( Number)

 - Used (Number)

 - Stock on Hand (Calucalted [Required Stock - Used])

At present i have a gallery in power apps that reads Item, Stock on Hand, and ID from from the sharepoint list.   A user clicks on the item and they use a slider to determine how many of that stock they need.  They then add it into a collection called ShoppingCart.

Collect(ShoppingCart, {ItemType:GalleryStationary.Selected.Title1,OrderQuantity:Slider1.Value,ID:GalleryStationary.Selected.Body1});Navigate('Browse Screen',ScreenTransition.Cover)

Fron there they click on the cart and go to the cart screen Where they review the items and then submit the changes.

Hope this helps.  Let me know if you need more info

[aprildunnam]

Unless I'm missing something it looks like in your ShoppingCart Gallery you are passing in "Body1 as the ID instead of the ID of the item.  This would cause the data mismatch error you're getting because you are trying to compare a number to a text value.