Extending Expressions Overview
Expressions can easily be extended by providing user functions written in any .NET language. This is very useful in addition to the built-in functions, providing more complex domain-specific calculations or uniform calculations because it speeds up the processing and boosts the performance. Furthermore, you can add custom aggregate functions to apply domain-specific logic while accumulating values.
In order to expose your custom functions, so they can be utilized by the Reporting engine, you have to add a reference to the assembly they are defined in. The reference is added under the AssemblyReferences configuration section in the application's configuration file.
<configuration>
<configSections>
<section
name="Telerik.Reporting"
type="Telerik.Reporting.Configuration.ReportingConfigurationSection, Telerik.Reporting"
allowLocation="true"
allowDefinition="Everywhere"/>
</configSections>
…
<Telerik.Reporting>
<AssemblyReferences>
<add name="MyCustomAssembly" version="1.0.0.0" />
</AssemblyReferences>
</Telerik.Reporting>
</configuration>