PS0204: Invalid Property Name in Configuration File


Severity	Error
Reported by	PostSharp
Message	`Invalid property name "<PropertyName>": the name of a property must start with a letter and contain only letters and digits.`

Cause

The Property element of a postsharp.config file defines a property of the project, which other elements read in expressions such as {$LoggingEnabled}. See Configuration File Schema Reference. Because expressions refer to properties by name, the name of a property must start with a letter and contain only letters and digits. A hyphen, a dot, an underscore or a space makes it invalid. Spaces before and after the name are ignored.

PostSharp reports PS0204 on the Property element, and ignores the property. Since the error occurs while PostSharp loads the configuration of the project, it also reports PS0084 and stops the build.

In the following example, the name of the property contains a hyphen.

Full screen

<?xml version="1.0" encoding="utf-8"?>
<Project xmlns="http://schemas.postsharp.org/1.0/configuration">
  <!-- The name of a property cannot contain a hyphen. -->
  <Property Name="Logging-Enabled" Value="True" />
</Project>

Full screen

using System;
using PostSharp.Aspects;
using PostSharp.Serialization;

namespace Errors.PS0204_Error;

[PSerializable]
public class LogAttribute : OnMethodBoundaryAspect
{
    public override void OnEntry( MethodExecutionArgs args )
    {
        Console.WriteLine( $"Entering {args.Method.Name}." );
    }
}

public class OrderService
{
    [Log]
    public void PlaceOrder( string product )
    {
        Console.WriteLine( $"Order placed for {product}." );
    }
}

public static class Program
{
    public static void Main()
    {
        new OrderService().PlaceOrder( "Coffee" );
    }
}

Full screen

error PS0084: The project could not be initialized because of the previous errors.
error PS0204: postsharp.config(4,4): Invalid property name "Logging-Enabled": the name of a property must start with a letter and contain only letters and digits.

Resolution

Rename the property so that its name contains only letters and digits, and update the expressions that refer to it.

In the following example, the property is named LoggingEnabled.

Full screen

<?xml version="1.0" encoding="utf-8"?>
<Project xmlns="http://schemas.postsharp.org/1.0/configuration">
  <!-- The name of the property contains only letters and digits. -->
  <Property Name="LoggingEnabled" Value="True" />
</Project>

Full screen

using System;
using PostSharp.Aspects;
using PostSharp.Serialization;

namespace Errors.PS0204_Fixed;

[PSerializable]
public class LogAttribute : OnMethodBoundaryAspect
{
    public override void OnEntry( MethodExecutionArgs args )
    {
        Console.WriteLine( $"Entering {args.Method.Name}." );
    }
}

public class OrderService
{
    [Log]
    public void PlaceOrder( string product )
    {
        Console.WriteLine( $"Order placed for {product}." );
    }
}

public static class Program
{
    public static void Main()
    {
        new OrderService().PlaceOrder( "Coffee" );
    }
}

Full screen

Entering PlaceOrder.
Order placed for Coffee.

Cause

Resolution

See Also