How to load a child object in appsetting.json (asp.net core) - asp.net-core

Question

I'm writing a little Action Filter for an ASP.NET Core web API project. The filter is for testing the associated UI for error handling. It will throw an error if a specific verb and method is invoked. The filter isn't a problem. The problem is the appsettings.configuration.
Here's what I'm trying to do:
appsettings.development.json
"FaultTesting": {
"FaultRequests": false,
"SlowRequests": 0,
"FaultCalls": [
{
"Path": "/api/usercontext",
"Verbs": "get,put,delete"
},
{
"Path": "/api/cafeteriaaccounts",
"Verbs": "get"
}
]
}
These are my c# types to hold the configuration:
public class FaultTestingOptions
{
/// <summary>
/// If true, checks FaultCalls for a path and verb to match.
/// </summary>
public bool FaultRequests { get; set; }
/// <summary>
/// Number of milliseconds to delay the response.
/// </summary>
public int SlowRequests { get; set; }
public FaultCall[] FaultCalls { get; set; }
}
public class FaultCall
{
public string Path { get; set; }
public string Verbs { get; set; }
}
Add what I'm doing in startup:
services.AddMvc(config =>
{
...
FaultTestingFilter(Options.Create(GetFaultTestingOptions())));
...
});
private FaultTestingOptions GetFaultTestingOptions()
{
var options = new FaultTestingOptions
{
FaultRequests = Configuration["FaultTesting:FaultRequests"].ToBoolean(),
SlowRequests = Convert.ToInt32(Configuration["FaultTesting:SlowRequests"])
};
var calls = Configuration.GetSection("FaultTesting:FaultCalls")
.GetChildren()
.Select(x => x.Value)
.ToArray();
var fooie = Configuration["FaultTesting:FaultCalls"];
//options.FaultCalls = calls.Select(c => new FaultCall { Path = c, Verbs = c.Value });
return options;
}
"calls" is an array of two nulls, fooie is null.
What's the right approach here?

Answer 1

Better option is to bind TOption in ConfigServices method and then inject it to you filer. It work same as default model binder work, you did not need to manually read and set values.
ConfigureServices Method:
public void ConfigureServices(IServiceCollection services)
{
services.Configure<FaultTestingOptions>(option => Configuration.GetSection("FaultTesting").Bind(option));
// Add framework services.
services.AddMvc();
}
Injecting in filter:
private readonly IOptions<FaultTestingOptions> config;
public FaultTestingFilter(IOptions<FaultTestingOptions> config)
{
this.config = config;
}
Accessing the properties.
var SlowRequests= config.Value.SlowRequests;
var FaultCalls= config.Value.FaultCalls;