Multi ComboBox selection in Canvas APP

[FrankEsch]

Hi PowerApps community, 

I've made a canvas app, with a gallery filtered by three combo boxes. The data source is a Collection filled by a Dataverse instance.

The image below, shows the app when i open it the first time. 

This is the ITEMS selection  FX of the gallery. 

If(IsBlank(ComboBox1)

&& IsBlank(ComboBox1_1)

&& IsBlank(ComboBox1_2),TempCompetences

If(Not(IsBlank(ComboBox1))

&&Not(IsBlank(ComboBox1_1))

&&Not(IsBlank(ComboBox1_2)),

Filter(TempCompetences,Person.Person exactin ComboBox1.SelectedItems.Person,Product.Product exactin ComboBox1_1.SelectedItems.Product,Value.Value exactin ComboBox1_2.SelectedItems.Value),

If(Not(IsBlank(ComboBox1))

&&(IsBlank(ComboBox1_1))

&&(IsBlank(ComboBox1_2)),

Filter(TempCompetences,Person.Person exactin ComboBox1.SelectedItems.Person),

If(Not(IsBlank(ComboBox1))

&&Not(IsBlank(ComboBox1_1))

&&(IsBlank(ComboBox1_2)),

Filter(TempCompetences,Person.Person exactin ComboBox1.SelectedItems.Person,Product.Product exactin ComboBox1_1.SelectedItems.Product),

If(IsBlank(ComboBox1)

&&Not(IsBlank(ComboBox1_1))

&&(IsBlank(ComboBox1_2)),

Filter(TempCompetences,Product.Product exactin ComboBox1_1.SelectedItems.Product),

If(IsBlank(ComboBox1)

&&(IsBlank(ComboBox1_1))

&&Not(IsBlank(ComboBox1_2)),

Filter(TempCompetences,Value.Value exactin ComboBox1_2.SelectedItems.Value),

If(IsBlank(ComboBox1)

&&Not(IsBlank(ComboBox1_1))

&&Not(IsBlank(ComboBox1_2)),

Filter(TempCompetences,Product.Product exactin ComboBox1_1.SelectedItems.Product,Value.Value exactin ComboBox1_2.SelectedItems.Value))))))))

below the image after selection.

Below an image after deselection

The initial selection works fine, but when i deselected a item, no results are displayed.  What can i do to fix this?

All help is appreciated.

[RandyHayes · Accepted solution]

@FrankEsch 

Please consider changing your Formula to the following:

Filter(TempCompetences,
     (CountRows(ComboBox1.SelectedItems)=0 || Person.Person exactin ComboBox1.SelectedItems.Person) &&
     (CountRows(ComboBox1_1.SelectedItems) =0 || Product.Product exactin ComboBox1_1.SelectedItems.Product) &&
     (CountRows(ComboBox1_2.SelectedItems) =0 || Value.Value exactin ComboBox1_2.SelectedItems.Value)
)

I hope this is helpful for you.

[FrankEsch]

Awesome, this work's!! Thank you so much. 

[FrankEsch]

I'm sorry,  i have one more question, tried to figure it out by myself, but i can't get it working. If i start the app the first time, now my Gallery is empty, the comboboxes now start's working after i selected an item in each one of them, but not if they are empty or after is select a single item. 

[RandyHayes]

@FrankEsch 

You appear to have a value in the one combo...where and why is that getting set?

[FrankEsch]

@RandyHayes ,

That is a custom field in my custom value entity/table. It's basically a score to show how good someone is in a certain Competence/Product. This screenshot is taken right after i selected "4", the first time the app starts. I want it to show every record with the value "4". If i would select a value in the other comboboxes, the formula starts behaving as i want, but it works not from the start. I show you a screenshot with the next steps, where i select the other comboboxes and then deselect. 

[FrankEsch · Accepted solution]

Fixed it, I had to put [] in the default Items selection property for each of the comboboxes.