Passing items to component dropdown

[Msag]

Because we cannot connect data sources directly to component, I am trying to pass what I need through an input property.

I created an custom table property called "StorageTable" like this:

Table({Text: "Storage", DropdownItems: ["a","b","c","d"], Plot: true})

In my component named "AddStorage", I have a drop down menu which Items property I set to:

AddStorage.StorageTable.DropdownItems

But that dropdown does not display anything. Though if I set the Items property to ["a","b","c","d"], it shows all four letters as options.

What am I missing? Should I pass the dropdown items to the component in a different way?

[RandyHayes · Accepted solution]

@Msag 

No, you definitely don't want to connect the datasource to a component in a dependency!!

Your problem is that you are referencing a table.  Your StorageTable is just that...a table.  But yet you are trying to connect your Dropdown to a column in the record of a table.  So, your formula for the Items is not the table you want.  It is going to be a table of the tables.

Is there a reason you need your StorageTable as a table?  Does each record of your storage table have different dropdown choices?  If so, then the dropdown needs to be in the context of the record of the table...not the table itself.

So, either you put your dropdown in a Gallery (with an Items property of Parent.StorageTable) and then set the Dropdown Items to: ThisItem.DropdownItems

OR, put the Dropdown Items into their own input property of your component.

I hope this is helpful for you.

[Msag]

Hi @RandyHayes 

Thank you very much for your quick answer!! So using a Gallery did work like a charm, though I did not understand why that worked 😅. So the Gallery component is like a Table reader?

I tried to create a custom property just for the drop down, but could not work out what it should look like. Should it be a record? How should I write the variable then, ["a","b","c","d"] ?

The reason why I shoved everything in StorageTable is just so I have all my inputs for my form in one variable. I don't like it when components have dozen of properties (it goes real quick as soon as you try to have things modular), so I thought it would be a good idea to keep things clean by sorting them in dedicated tables: StorageTable, ContainerTable (another StorageTable like), DesignTable (parameters for the components design),...  

[RandyHayes]

@Msag 

No, go ahead and separate out parameters and avoid clumping them all together.  Besides that, you will undoubtedly need to make an adjustment at some point in the table record of your parameter - and components do not like that!!  They get really screwy at that point and need several hoops to jump through to correct them.

If you are specifying ["a","b","c","d"] - well, that is a Table.  So your parameter would be a Table parameter and the table would be defined as you have it - ["a","b","c","d"]   (Or Table({Value:"a"}) - which is equivalent)

The only reason I mentioned a Gallery is because your primary parameter is a table and each record of that table is expected to have a table for dropdown items (as per your schema).  I don't believe that is what you want and the point was, the only way to deal with that is in context to the record of the table...a gallery would demonstrate that.

But anyway...your dropdown parameter should be a totally separate parameter to your component and not mixed in with another (to keep it simple and clean)

Hope that makes sense!

[Msag]

@RandyHayes 

Ok, I'll split up the variables, thanks for the advice and for taking the time to explain me all of this ! 🙂 

Have a great day

[Msag]

@RandyHayes 

I actually still have a problem with this sorry 😶

Still with the same component. Everything work using your solution. but I cannot find the correct way to pass the table down to the component from the main application.

The table I would like to pass through is a column coming from a Microsoft list. So on the component side I have a property called StorageList: 

StorageList = ["a","b,","c","d"]

That list is plug to a combobox using:

Items = AddStorage.StorageList.Value

 I had to switch to a combobox to allow the user to add its own input in case it was not in the list. So in the component there is a button with an OnSelect property like:

OnSelect = Set(_Category, If(IsBlank(ComboBox.Selected.Value), ComboBox.SearchText, ComboBox.Selected.Value));

Where _Category is plugged into an output property for the component called CategoryOuput.

When I load that component into the main app, I try to set set the component input using:

AddStorage.StorageList = Disctinct(Storage, Category)

Where Storage is the Microsoft List and Category one of its columns. PowerApps does not like that, and tells me "Storage does not have a Value column". This is true and I see why it is looking for one as 

["a","b,","c","d"] = Table({Value:"a"},{Value:"b"},{Value:"c"},{Value:"d"})

I tried modifying the default value of StorageList in the component to:

StorageList = Table({Category:"a"},{Category:"b"},{Category:"c"},{Category:"d"})

I update the button formula:

OnSelect = Set(_Category, If(IsBlank(ComboBox.Selected.Category), ComboBox.SearchText, ComboBox.Selected.Category));

And I tried seting the value of the input property in the main app to:

AddStorage.StorageList = Disctinct(Storage, Category)

or

Storage

And now it tells me it cannot find a Category column in the Storage table, though this column exists and the data is correctly up to date in the app (I tried with a other column name, same thing).

What am I missing? 

[RandyHayes]

@Msag 

Sorry for the delay in response.  Still having an issue with this??

I noticed that your primary issue is that you are trying to set your StorageList to:

Disctinct(Storage, Category)

When you use Distinct you will get a table with a single column called Result.  This will NOT match the Value column you defined in your component table.

[Msag]

@RandyHayes 

No worries, thank you for answering ! 🙂 Yes I indeed solved it by:

1. Not using Distinct but GroupBy instead

2. Re-enabling an old feature: https://powerusers.microsoft.com/t5/Building-Power-Apps/Component-Output-Properties-suddenly-generat...

Thank you for time and patience!

[RandyHayes]

@Msag 

Okay.

You'll want to clean up your record definition in your component then soon.  That particular feature is retiring and will at some point be removed - and then what you have working now with it, will break!