Option to convert Arguments object back into args string about commandline

[ericnewton76]

Comment by issacg
Wednesday Dec 18, 2013 at 16:09 GMT

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It works now.

https://gist.github.com/issacg/8024973

[ericnewton76]

Comment by allonhadaya
Wednesday Dec 18, 2013 at 15:43 GMT

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Nice! Not sure about how this all fits into the library, but I played around with your code and came up with this. It uses some more linq and extracts the functionality into an abstract base class.

using System;
using System.Linq;
using CommandLine;

/// <summary>
/// A base class for options that can be turned back into an argument string.
/// </summary>
public abstract class ReversableOptions
{
    public override string ToString()
    {
        return string.Concat(this
            .GetType()
            .GetProperties()
            .Where(p => Attribute.IsDefined(p, typeof(OptionAttribute)))
            // for all properties with option attributes
            .SelectMany(p => p
                .GetCustomAttributes(typeof(OptionAttribute), inherit: true)
                .Select(a => (OptionAttribute)a)
                // get the type, name, and data
                .Select(a => new {
                    type = p.GetType(),
                    name = a.LongName,
                    data = p.GetValue(this, null)
                })
                // where data is not default
                .Where(v => v.data != ((v.type.IsValueType) ? Activator.CreateInstance(v.type) : null))
                // make an argument string
                .Select(v => string.Format("--{0} {1} ", v.name, v.data))));
    }
}

I was kicking around the idea of making a tag interface with a single Reverse extension, but every implementer would have to do something like this:

class MyOptions : ISomeTag
{
    public override string ToString()
    {
        return this.Reverse();
    }
}

which seems a bit crufty.

Anyways, hope this helps.

[ericnewton76]

Comment by issacg
Wednesday Dec 18, 2013 at 15:52 GMT

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Yeah, the Reverse tag would be a bit sucky. I don't really have a better idea, though. Maybe just leave the ToString code as a Gist and mention it in the docs...

I tried using your ToString as a drop-in replacement to mine, and it actually did not seem to work - I'll try to find some time tomorrow to look into it

[ericnewton76]

Comment by allonhadaya
Wednesday Dec 18, 2013 at 15:54 GMT

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Yeah, I think I just found the bug... A small typo.

[ericnewton76]

Comment by allonhadaya
Wednesday Dec 18, 2013 at 16:00 GMT

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Sorry about that, just updated my earlier comment with the fix. I think a gist would be a good place to start.

[moh-hassan]

The class UnParserExtensions convert Arguments object back into args string