commandlineparser / commandlineparser/commandline

How can I assign TypeConverter to Enum in `Options`?

Open
#944 0 comments 0 reactions 0 assignees View on GitHub
Dominant language
C#
Stars
4.8k
Forks
478
PR merge metrics
No merged PRs in 30d

Description

I've declared `Options` which will be used for parsing command line.
```csharp
public class Options {
// ...
[Option('o', "operation", HelpText = "")]
[TypeConverter(typeof(OperationConverter))]
public Operation Operation { get; set; }
}
```
And the `Operation` looks like this:
```csharp
[TypeConverter(typeof(OperationConverter))]
public enum Operation {
// ...
CreateDirectory,
// ...
}
```
Since `CreateDirectory` is quite long to type in command line, I want to allow `cd` as valid `Operation.CreateDirectory`
```csharp
public class OperationConverter : EnumConverter {
// ... candidates for other enum values
private static readonly List OperationCandidate = ["createdirectory", "cd"];

// ...
public override object ConvertFrom(ITypeDescriptorContext? ctx, CultureInfo? ci, object value) {
if (value is string s) {
string l = s.Trim().ToLowerInvariant();
// ...
if (OperationCandidate.Contains(l)) return Operation.CreateDirectory;
// ...
}
}
}
```
But I can't assign this `OperationConverter` to `Options.Operation`. I don't see anything that might be related to this.

#83 says it is resolved, but at the bottom of that issue, [someone](https://github.com/commandlineparser/commandline/issues/83#issuecomment-671916065) said:
> I dont think this works in the latest version. I tried annotating my option's property, but the converter is not invoked. Instead I had to register it using `TypeDescriptor.AddAttributes()`.

But I don't see any methods named `.AddAttributes()` in [`TypeDescriptor`](https://github.com/commandlineparser/commandline/wiki/T_CommandLine_Core_TypeDescriptor). [this](https://learn.microsoft.com/en-us/dotnet/api/system.componentmodel.typedescriptor?view=netframework-4.8.1#methods) has `.AddAttributes()`, but this doesn't seem to work.
```csharp
private static void Main(string[] args) {
// ...
TypeDescriptor.AddAttributes(typeof(Operation), new TypeConverterAttribute(typeof(OperationConverter)));
// other logic + command line parsing
}
```

Now I'm completely lost. Wiki doesn't provide any useful information that I can easily access.

How can I assign TypeConverter to Enum in Options?

Contributor guide

No contributing guide indexed for this repository

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.