Given the following service:
public class MySuperService
{
public MySuperService(string connectionString)
{
//..
}
}
I want Windsor automatically to look at the web.config or app.config settings and if there is a configuration with key equals to the parameter name (i.e. “connectionString”) to inject automatically the value when constructing MySuperService instance.
The infrastructure code is this:
public class DependenciesFromAppSettings : AbstractFacility
{
protected override void Init()
{
var dic = ConfigurationManager
.AppSettings
.AllKeys
.ToDictionary(k => k, k => ConfigurationManager.AppSettings[k]);
Kernel.Resolver.AddSubResolver(new DependenciesFromAppSettingsResolver(dic));
}
}
public class DependenciesFromAppSettingsResolver : ISubDependencyResolver
{
private readonly IDictionary webConfig;
public DependenciesFromAppSettingsResolver(IDictionary webConfig)
{
this.webConfig = webConfig;
}
public object Resolve(
CreationContext context,
ISubDependencyResolver contextHandlerResolver,
ComponentModel model,
DependencyModel dependency)
{
return webConfig[dependency.DependencyKey];
}
public bool CanResolve(
CreationContext context,
ISubDependencyResolver contextHandlerResolver,
ComponentModel model,
DependencyModel dependency)
{
return dependency.DependencyType == DependencyType.Parameter
&& webConfig.ContainsKey(dependency.DependencyKey);
}
}
And the usage is very straightforward:
[TestFixture] public class DependenciesFromAppSettingsTests { [Test] public void CanInjectSettingsFromAppConfig() { var container = new WindsorContainer(); container.AddFacility<DependenciesFromAppSettings>(); container.Register(Component.For<MySuperService>()); var superInstance = container.Resolve<MySuperService>(); superInstance.ConnectionString .Should().Be.EqualTo("sample conn string"); } }
