How to Use the Selected Object

2026-04-10
Morten Lønskov

Applies to:

✔ Tabular Editor 2
✔ Tabular Editor 3

The Selected object provides access to whatever is currently selected in the TOM Explorer view tree. Use it to write scripts that operate on user-selected objects rather than hardcoded names.

Quick reference

// Singular (exactly one selected, throws if 0 or 2+)
Selected.Measure
Selected.Table
Selected.Column

// Guard clause
if (Selected.Measures.Count() == 0) { Error("Select at least one measure."); return; }

// Iterate and modify
foreach (var m in Selected.Measures)
    m.FormatString = "0.00";

// Using ForEach extension
Selected.Measures.ForEach(m => m.DisplayFolder = "KPIs");

Plural accessors (zero or more, safe to iterate):

Selected.Measures
Selected.Tables
Selected.Columns
Selected.Hierarchies
Selected.Partitions
Selected.Levels
Selected.CalculationItems
Selected.Roles
Selected.DataSources

Singular vs plural accessors

The Selected object exposes both singular and plural accessors for each object type.

Accessor	Returns	Behavior when count is not 1
`Selected.Measure`	single `Measure`	Throws exception if 0 or 2+ measures selected
`Selected.Measures`	`IEnumerable<Measure>`	Returns a collection that may be empty but is never null. Safe to iterate directly.

Use the singular form when your script requires exactly one object. Use the plural form when the script should work on zero or more objects.

Guard clauses

The plural accessor returns zero or more objects. A script may silently do nothing with an empty collection, or require a minimum count. Use a guard clause for the latter.

// Require at least one measure
if (Selected.Measures.Count() == 0)
{
    Error("No measures selected. Select one or more measures and run again.");
    return;
}

// Require exactly one table
if (Selected.Tables.Count() != 1)
{
    Error("Select exactly one table.");
    return;
}
var table = Selected.Table;

For scripts that accept multiple object types, combine checks:

if (Selected.Columns.Count() == 0 && Selected.Measures.Count() == 0)
{
    Error("Select at least one column or measure.");
    return;
}

Iterating selected objects

The plural accessor returns a collection you can iterate with foreach or LINQ.

// Set display folder on all selected measures
foreach (var m in Selected.Measures)
    m.DisplayFolder = "Sales Metrics";

// Hide all selected columns
Selected.Columns.ForEach(c => c.IsHidden = true);

// Add to a perspective
Selected.Measures.ForEach(m => m.InPerspective["Sales"] = true);

Working with the selected table

When a single table is selected, use Selected.Table to add new objects to it.

var t = Selected.Table;
t.AddMeasure("Row Count", "COUNTROWS(" + t.DaxObjectFullName + ")");

Mixed selections

When you need to handle multiple object types from the selection, iterate Selected directly. The Selected variable itself implements IEnumerable<ITabularNamedObject>.

foreach (var desc in Selected.OfType<IDescriptionObject>())
{
    desc.Description = "Reviewed on " + DateTime.Today.ToString("yyyy-MM-dd");
}

See How to Filter and Query Objects with LINQ for more on LINQ filtering and Key TOM Interfaces for interface-based object handling.

Try/catch for selection dialogs

When using SelectTable(), SelectColumn(), or SelectMeasure() helper methods, wrap them in try/catch to handle user cancellation.

try
{
    var table = SelectTable(Model.Tables, null, "Pick a table:");
    Info("You selected: " + table.Name);
}
catch
{
    Error("No table selected.");
}

Note

The Selected object is only available in interactive contexts (Tabular Editor UI and macros). When running scripts via the CLI with the -S flag, Selected reflects the objects specified by -O arguments or is empty if none are specified.

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