How to use a placeholder without referencing a data object?

[mariusz96]

Hi! Thanks for reporting this bug!

Please fill in the relevant information from this template so that we can help you best.

Smart.Format version:
3.5.1
Framework version: (e.g. net5.0)
net9.0

• Please provide a working source code example to reproduce the bug

using SmartFormat;
using SmartFormat.Extensions;

var formatter = Smart.CreateDefaultSmartFormat(); // https://github.com/axuno/SmartFormat/wiki/Templates-_-TemplateFormatter
var templates = new TemplateFormatter();
formatter.AddExtensions(templates);
templates.Register("SomeTemplate", "The template content");

formatter.Format("{0:t(SomeTemplate)}:"); // This line throws.

• What is the current result?

SmartFormat.Core.Formatting.FormattingException: 'Error parsing format string: No source extension could handle the selector named "0" at 1
{0:t(SomeTemplate)}:
-^'

• What is the expected result?
  no exception
• Please post full exception details if applicable (message, stacktrace, inner exceptions)
• Did you find a workaround? yes/no
  yes, pass redundant new object() argument
• Is there a version in which it worked?
• Can you help us by writing an unit test?

Our actual use case is for sms templates and looks more like this:

var filePaths = Directory.GetFiles(path);

foreach (string filePath in filePaths)
{
    string fileName = Path.GetFileNameWithoutExtension(filePath);
    string fileText = await File.ReadAllTextAsync(filePath);

    templates.Register(fileName, fileText);
}

and I found some smses don't need a model.