This example illustrates how to add a custom function to the designer and use it in the report template.

First, you need to add the StiBlazorDesigner component to the view page. Next, register new function:

@using Stimulsoft.Report.Blazor;

...

<StiBlazorDesigner Report="@Report" Theme="StiDesignerTheme.Office2013LightGrayCarmine" />

...

// Register function
StiFunctions.AddFunction("MyCategory", "MySum",
	"description", typeof(CustomFunction),
	typeof(decimal), "Calculates a sum of the specified set of values.",
	new[] { typeof(object) },
	new[] { "values" },
	new[] { "A set of values" }).UseFullPath = false;
...

Finally, create report object and load the report template:

...
// Create empty report object
var report = new StiReport();

// Load report template
report.Load("Reports/CustomFunction.mrt");
...

In the screenshot below you can see the result of the sample code: