TemplateFill refresh in gallery

[Asmo57]

Hi,

My data model consists of a main table and a lot of related tables (with foreign keys to the main one). I try to highlight the fact that the user already filled a sub table or not. To this purpose I used the TemplateFill property of my gallery with a LookUp testing if the data object is blank or not.

If(IsBlank(LookUp(DataSourceTable,GniID=galInspections.Selected.gni_id)),White,GreenYellow)

It works fine on first loading (Bleeder table not yet filled in in this screenshot) but when I try to refresh the display (directly after the save in Bleeder table for example), my back color never changes. I tried to refresh the various data sources (directly after the save, in the OnVisible of the MainScreen, with a manual button also) but it does not work. 

Is there a way to force a refresh of the TemplateFill property?

Thanks in advance.

[poweractivate]

@Asmo57 

Lookup returns a table - recommend to use IsEmpty rather than IsBlank if checking for whether table returned contains any rows.

https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-isblank-isempty

The IsBlank function tests for a blank value or an empty string. The test includes empty strings to ease app creation since some data sources and controls use an empty string when there is no value present. To test specifically for a blank value use if( Value = Blank(), ... instead of IsBlank.

The IsEmpty function tests whether a table contains any records. It's equivalent to using the CountRows function and checking for zero. You can check for data-source errors by combining IsEmpty with the Errors function.

The return value for both IsBlank and IsEmpty is a Boolean true or false.

[v-siky-msft]

Hi @Asmo57 ,

Could you share more details with the lookup condition and DataSourceTable?

What is the data source of gallery? DataSourceTable?

What I confused about is that the formula you used is not related to gallery items.

If the gallery is from DataSourceTable, please try this

If(ThisItem.GniID=galInspections.Selected.gni_id,GreenYellow,White)

If this doesn't make sense, please share more details.

Sik

[Asmo57]

@poweractivate 

The formula works fine with isBlank but not with IsEmpty, just tested.

@v-siky-msft 

The gallery uses a variable defined in the OnVisible event (MenuIcons). Like this:

ClearCollect(
	MenuIcons,
	{
		Title: "BF General Data",
		Image: BF,
		Screen: BFGeneralDataScreen,
		DataSourceTable: '[Ins].[View_BFGeneralData]'
	},
	{
		Title: "BLT Hydraulics",
		Image: HYD,
		Screen: BLTHydraulicsScreen,
		DataSourceTable: '[Ins].[View_BLTHydraulics]'
	},
...)

The behavior is ok at start-up but not well refreshed when underlying tables are updated.

[v-siky-msft]

@Asmo57  I can't find any relationship between 'MenuIcons' and 'DataSourceTable' in the formula.

could you describe more about how to check if users has filled a sub table or not?

we need more information.

Sik

[Asmo57]

My MenuIcons variable contains a list of objects. These objects have a property DataSourceTable which is the name of a SQL Server view. All these views share the same structure, two fields ID (primary key of the subtable) and GniID (foreign key to the main table).

When browsing my main gallery I get the current GniID to check.

I then check for every subtables (members of the second gallery) if there is some data for this current GniID with this formula:

If(IsBlank(LookUp(DataSourceTable,GniID=galInspections.Selected.gni_id)),White,GreenYellow)

Here is the SQL code of one of the views:

ALTER view [Ins].[View_Bleeder]
AS
select ble_id AS ID,ble_gni_id AS GniID from [Ins].[Bleeder_ble]

Hope I'm clear... 🙂

Imo the formula is correct because the coloring is good on first execution. But it is not correctly re-calculated everytime data changes in the subtables.