SolrNet Autofac - Use SolrPostConnection

Question

I'm using SolrNet with Autofac DI in my web application like this:

var solrNetModule = new SolrNetModule(ConfigurationManager.ConnectionStrings["solr"].ConnectionString);
solrNetModule.HttpWebRequestFactory = new BasicAuthHttpWebRequestFactory("****", "****");
builder.RegisterModule(solrNetModule);

My queries are quite long and sometimes end up with a 404 in Jetty, I'm pretty sure this happens because the length of the URL.

I've been reading about the SolrPostConnection and that sounds like a proper solution to my problem, but I'm having trouble implementing it in my Autofac setup.

I know the Autofac SolrNetModule integration internally uses

builder.RegisterInstance(solrConnectionInstance).As<ISolrConnection>();

But I can't figure out how to override it or .Register Autofac to use the SolrPostConnection instead.

Answer 1

Looks like you need to override registration for interface ISolrConnection. The main problem is that SolrNetModule doesn't provide mapping of SolrConnection to itself. Try out the example below. I added another registration of SolrConnection to make it available for injecting to contructor of PostSolrConnection without dependency loops

[Test]
public void SolrRegistrationOverride()
{
    // Arrange
    var builder = new ContainerBuilder();
    var serverUrl = ConfigurationManager.ConnectionStrings["solr"].ConnectionString;
    var httpWebRequestFactory = new BasicAuthHttpWebRequestFactory("****", "****");
    var solrNetModule = new SolrNetModule(serverUrl);
    solrNetModule.HttpWebRequestFactory = httpWebRequestFactory;
    builder.RegisterModule(solrNetModule);

    builder.RegisterType<SolrConnection>().AsSelf()
           .WithParameter(new NamedParameter("serverURL", serverUrl))
           .WithProperty("HttpWebRequestFactory", httpWebRequestFactory).AsSelf()
           .SingleInstance();

    builder.RegisterType<PostSolrConnection>().As<ISolrConnection>()
           .WithParameters(new Parameter[]
           {
               new ResolvedParameter((prm, сtx) => prm.Name == "conn", (prm, ctx) => ctx.Resolve<SolrConnection>()),
               new NamedParameter("serverUrl", serverUrl)
           });

    var container = builder.Build();

    // Act
    var conn = container.Resolve<ISolrConnection>();

    // Assert
    Assert.IsInstanceOf<PostSolrConnection>(conn);
}

Hope it helps.