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jessej1111
New Member

use a variable as a datasource in a function

Hello,

 

I am new to powerapps and am having an issue I hope everyone can help me with. I have searched the forums and google for hours and still can not seem to find if there is actually a way to do this.

 

LONG STORY SHORT: I want to use a variable to specifiy a datasource in a function such as "search" and "remove"

Please see below for the LONG version.

 

BACKGROUND / SETUP

I have a small powerapp where I have a list of items.

When an Item is selected it passes to a browse gallery and displays a list of items.

When an item is selected it goes to a form and shows the properties of the item.

You can then edit the item and click a save button and it saves the item or you can click a delete button and it deletes the item.

 

Right now I have this working using chained "if" statements however, that is difficult as every time I add a new item to the list on the first page it requires me to go modify the chained if statements in other locations of the app.

 

I have multiple datasources.

The list on the front page is 1 datasource. Each item you can selected is its own datasource as well.

The datasources are all tables from an XLSX on one drive.

 

ISSUE

My issue is that when I try to not use chained "if" statements but instead try to use a variable to specify a datasource it does not work.

 

Example: List on the front page is "Jim", "Billy", "Bob"

I select "Jim"

When selected I have the code:

Set(personselected, SiteDropdown.Selected.Value);

Navigate(PersonList, ScreenTransition.Fade)

 

As you can see I am setting a global variable "personselected" to the value of the dropdown selected value.

I am then going to the "PersonList" screen.

 

On the screen "PersonList" I have a browse gallery. I currently have the code for Items:

"If(personselected = "Jim",SortByColumns(Search(Jim, TextSearchBox1.Text, "NAME"),"NAME",If(SortDescending1, SortOrder.Descending, SortOrder.Ascending)"

 

This works perfectly and does in fact show what I exptect it to.

I have the arrorw for the item set to the code for "OnSelect" to:

Navigate(ChangeRecord,ScreenTransition.Fade)

 

This sends you to the "ChangeRecord" screen

 

On the "ChangeRecord" screen I have the "OnVisible" property set to the code:

If(personselected = "Jim",Set (persondata, Jim)

This seems redundant but its that way in case the dropdown does not match the datasource name exactly.

 

I then have a form on the changerecord screen and the "DataSource" property is set to: "persondata"

I also have the "Item" property of the form set to "BrowseGallery1.Selected"

 

I then have a "remove" button on the "ChangeRecord" screen with the code:

If(personselected = "Jim",Remove(Jim,BrowseGallery1.Selected)

 

This again works as expected and without issues.

 

 

SOOOO your saying in your head get to the point already I am sure.

 

Lets start with the "remove" button

If I change the code to:

Remove(persondata,BrowseGallery1.Selected)

without the if statements

I end up getting the system complaining that "persondata" is not a collection.

 

If I try and change the code to:

Remove(personselected,BrowseGallery1.Selected)

without the if statements

I end up getting the system complaining that it is a "TEXT" entry and not valid.

 

I want to do this so I can only use 1 line of code instead of 20 lines of if statements as I currently have.

 

 

The idea is the same for the other places where I use the chained IF statements.

 

So long story short I want to use a variable as the name of a datasource.

 

Honestly if you guys have a better way to do this please tell me so I can go in that direction instead.

I was thinking maybe even dumping different datasources into a collection or table and trying something with that but I am not skilled enough to do that at this time and need your help if you think I should be doing that.

 

Please let me know if you can help me.

6 REPLIES 6
v-yamao-msft
Community Support
Community Support

Hi jessej1111,

 

Please try to use Switch function on your side to see if it will meet your scenario.


Add all the data sources you need to the app, say they are table1, table2, and table3.


Then add a Dropdown control, set its Items property as [“table1”, “table2”, “table3”].


Then set the screen’s OnVisible property as Switch(DrooDown1.Selected.Value, “table1”,table1,”table2”,table2,”table3”,table3)


This function will return correspond data source.


Hope this could be a reference for you.


Best regards,
Mabel Mao

Community Support Team _ Mabel Mao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Hi!

 

I'm just a bit curious and wonder if a different structure wouldn't be better?

 

Is the structure of the different data sources the same, they just belong to a different "owner" or person, or is the structure for each person different? I don't mean the data stored in the individual columns (what some would call fields), but the number of columns and their names and types.

 

If the structure is the same it would be better to have it all in one datasouce, but with an extra column containing the the user the row (or record) belongs to. That way you don't need to do a lot of extra work with the data sources, you can just Filter for the current user.

 

The upshot to this is that you don't have to change your app every time a person starts working or quits, it will all be taken care of automatically. Using User().FullName you will always know which user is currently using the app, so no need for extra coding.

 

Let me know if you have any more questions!

Thank you for this suggestion. I will try this sometime this week and report back my findings.

Any findings yet or should we check back in another year Smiley Wink

SaWu
Impactful Individual
Impactful Individual

Hi @jessej1111 

Short version: You cannot get rid of the conditional statement (If or Switch) when using Remove.
You can however use Variables to make the transitions and selected item settings of your Galleries and the Form better looking syntactically.

Long version:
The way I read your post, it appears to me as if you are mixing data types which are not interchangeable.
"Jim" is a string/Text.

'Jim' is probably a Data Source (or a Column Display Name).
Jim can bei either a Variable (Context Variable, Global Variable), or a Collection, or a Data Source.
Collections and Data Sources are Tables.
Variables can hold anything.
Variables cannot be used in places where Data Sources/Collections are required.

Functions which require Tables require Tables, e.g. no strings, no numbers, Collections are ok.
You can use a Variable that holds a Table.
https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-filter-lookup

Functions which require Data Sources (e.g. Patch, Remove) require a Data Source or Collection.
You must feed it a name which is assigned to a Data Source or Collection.
You cannot use a Variable even if that variable points to your data source.
https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-remove-removeif

In your example you have
image.png
It sounds to me as if you assign personselected to be the text "Jim".
This is why you later get the error
image.png

The statement which you say is working
image.png
removes the element from the Collection Jim (no quotes!) which is something entirely unrelated to the "Jim" and personselected.

Also the other statement which you say isn't working you have
image.png
creates a Global Variable persondata.
This is not a Collection.
Collections are only created by adding Data Sources or using Collect/ClearCollect/LoadData.
So naturally you get an error
image.png
that tells you that you are not using an collection.

You need some code in Remove that in end puts the name of your Data Source/Collection Jim in there.

SaWu
Impactful Individual
Impactful Individual

For what you want you would need a reference or pointer.
As far as I understand these are too technical and inherently unintended concepts for PowerApps.
Without those concepts it is impossible to have a "Variable" B that you set to another "Table/Collection/Data Source" A such that when you make a change to B (e.g. Remove(personselected, item)), A changes as well (the Jim table changes).

So something like

Set(VariableA, CollectionA)

creates a Global Variable VariableA that contains a Table with a copy of the data from CollectionA and

Collect(CollectionB, CollectionA)

creates another Collection CollectionB with a copy of the date from CollectionA.

An example using just a Button and a Label on a otherwise blank Canvas App:
Button1.OnSelect:

ClearCollect(CollectionA, ["a","b","c"]);
ClearCollect(CollectionB, CollectionA);
Set(VariableC, CollectionA);
Remove(CollectionA, {Value: "a"}, All);
Remove(CollectionB, {Value: "b"}, All);

Label1.Text:

"A: " & Concat(CollectionA, Value, ",") & "
B: " & Concat(CollectionB, Value, ",")

After pressing the button:
image.pngimage.pngimage.pngimage.png

Or similarly
image.pngimage.png

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