henkmollema / ConfigurationPlaceholders

Placeholder support for the ASP.NET Core Configuration framework.

Configuration Placeholders

Placeholder support for the ASP.NET Core Configuration framework.

Usage

Define placeholdes in your settings file. You can use multiple placeholders inside static strings.

{
  "FooService": {
    "Endpoint": "http://example.com/api/",
    "Resource": "resources/v2/"
  },

  "BarService": {
    "Endpoint": "[FooService:Endpoint]"
  },

  "BazService": {
    "Endpoint": "http://example2.com/api/[ASPNETCORE_ENVIRONMENT]/[FooService:Resource]"
  }
}

Build your configuration object and call ReplacePlaceholders():

public Startup(IHostingEnvironment env)
{
    Configuration = new ConfigurationBuilder()
        .SetBasePath(env.ContentRootPath)
        .AddJsonFile("appsettings.json")
        .AddEnvironmentVariables()
        .Build()
        .ReplacePlaceholders();
}

private IConfiguration Configuration { get; }

Use the configuration values:

var endpoint = Configuration["BazService:Endpoint"];
// http://example2.com/api/Development/resources/v2/

Samples

Check out the sample web app for more details.