is there a way of making use of .json configurations in .net core class library instead of a .config file

Question

I have a class library i want end up packaging into a nuget package, i have some configurations i wish to use which are in a json file (apsettings.json).

I have added this file to my class library project, and at the moment i just want to read the values in the configurations in a constructor without using a .config file, i will like to use a .json similar to how i'll do it in a web project.

I am trying something like this, but i get an error stating that the settings.json file does not exist in \bin\Debug\netcoreapp2.0. It is not in that folder, it is in the root of my project.

    public TokenGenerator()
    {
        var builder = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("settings.json");
        _configuration = builder.Build();

        _tokenServiceSettings = new TokenServiceSettings()
        {
            Audience = _configuration.GetSection("JwtBearer:Audience").Value
        };
    }

At the moment, i have just hard coded the directory as a string inside the SetBasePath method

Have you tried setting the path to your project's root folder? — benjrb, Mar 29 '18 at 16:06
If I understand your end goal correctly, see the answer on this post: https://stackoverflow.com/questions/21143817/set-content-files-to-copy-local-always-in-a-nuget-package/30386836#30386836 — Travis Acton, Mar 29 '18 at 16:29

score 3 · Answer 1 · answered Mar 29 '18 at 16:57

If you are writing a library that other teams might use in other projects, you should not bind it to another package (Microsoft.Extensions.Configuration) just for configuration.

You should have your own Option class which is a simple class with bunch of properties

public class TokenServiceOptions
{
    public TokenServiceOptions()
    {
        Audience = "Audience_Default_Value!";
    }

    public string Audience { set; get; }
    public string OtherOption1 { set; get; }
    public string OtherOption2 { set; get; }
    ///
}

and let your library users pass an instance of TokenServiceOptions to your method.

It should not be important to a library how options are gathered.

score 0 · Answer 2 · answered Mar 29 '18 at 16:30

Because this is in a library, this class cannot know where and what json file to read.

Pass the full path to the file to the library or,
Pass a structure as an argument to the library so the calling assembly can pass in the data and store it anywhere and any way it likes or
Get the location of the CallingAssembly (Assembly.GetCallingAssembly().Location) and construct a relative path to that.

is there a way of making use of .json configurations in .net core class library instead of a .config file

2 Answers2