#PowerPlatformTip 23: 'Filter Blank'

TL;DR: Add || IsBlank(YourFilterInput) to a gallery’s Filter so it shows every item while the search box is empty. Refer to columns by name inside Filter, not with ThisItem.

💡 Challenge

Filtering galleries in Power Apps based on user input (a text input, dropdown or combo box) is common, but when the input is empty you usually want to show all items instead of none.

✅ Solution

Add an || IsBlank(YourFilterInput) condition to your filter formula. When the input is empty, that part is true for every record, so nothing is filtered out.

🔧 How It’s Done

1. Create a gallery and add your filter input (text input, dropdown or combo box).

2. Set the gallery’s Items property:

   Filter(YourDataSource, Condition || IsBlank(YourFilterInput))
   

   Example with a text input:

   Filter(Projects, Title = txtSearch.Text || IsBlank(txtSearch.Text))
   

   🔸 YourDataSource is the table, list or collection.

   🔸 Condition compares a column with the input. Inside Filter you refer to the column by its name (Title) or with ThisRecord.Title. ThisItem belongs to the gallery template, not to Filter.

   🔸 IsBlank treats an empty string as blank, so an empty text box counts as “no filter”.

3. Use the right blank check per control type:

   // Dropdown
   Filter(Projects, Status = ddStatus.Selected.Value || IsBlank(ddStatus.Selected.Value))
   
   // Combo box (single select) with Items = Projects
   Filter(Projects, Region = cbRegion.Selected.Region || IsBlank(cbRegion.Selected.Region))
   

🎉 Result

When the filter input is empty, the gallery shows all items. As soon as the user enters or selects a value, the gallery filters on it.

🌟 Key Advantages

🔸 One formula instead of an If around two different Filter calls.

🔸 Users see data immediately instead of an empty gallery.

🔸 Scales to several inputs, each with its own blank check.

⚠️ Delegation

IsBlank(txtSearch.Text) doesn’t depend on any column, so Power Apps evaluates it once and sends it to the data source as a constant. Or (||), = and IsBlank are on the list of delegable operations for Filter, so this pattern itself doesn’t block delegation. Whether the whole formula is delegated depends on the operator in Condition and on the data source: StartsWith is delegable to SharePoint and Dataverse, the in operator is not delegable to SharePoint. If the formula is not delegable, the formula bar shows a delegation warning and Power Apps only processes the first 500 records (Data row limit, adjustable up to 10,000 in Settings), so records further down are missing from the gallery without an error.

🎥 Video Tutorial

🛠️ FAQ

1. Can I use multiple filter conditions with the IsBlank() check?

Yes. Give each input its own blank check and combine them with &&: Filter(DataSource, (Condition1 || IsBlank(Input1)) && (Condition2 || IsBlank(Input2))).

2. Does this technique work with all data sources in Power Apps?

The formula works with any data source that supports Filter. For large data, check the delegation warning: it depends on the data source and on the operator used in the condition, not on the IsBlank part.

3. Why is Filter(Projects, ThisItem.Title = txtSearch.Text) wrong?

ThisItem refers to the current record of a gallery or form template. Inside Filter, the record being checked is available by column name or through ThisRecord, so write Title = txtSearch.Text or ThisRecord.Title = txtSearch.Text.

🔗 Related Tips

🔸 #PowerPlatformTip 33: ‘Coalesce’ - replace nested If(IsBlank()) checks elsewhere in the same app with one function.

🔸 #PowerPlatformTip 38: ‘Data Refresh’ - keep this gallery’s data fresh without reloading everything on every keystroke.