Unable to create multiple OpenApi specifications with Swashbuckle

Question

I am building a solution with Asp.Net Boilerplate / Asp.Net Zero

I have created two OpenApi specifications (HostApiv1 and TenantApiv1) as follows in Startup.cs:

services.AddSwaggerGen(options =>
{
    options.SwaggerDoc("HostApiv1", new Info { Title = "Host API v1", Version = "v1" });
    options.SwaggerDoc("TenantApiv1", new Info { Title = "Tenant API v1", Version = "v1" });

    options.DocInclusionPredicate((docName, description) => true);
    options.IgnoreObsoleteActions();
    options.IgnoreObsoleteProperties();
    options.OrderActionsBy((apiDesc) => $"{apiDesc.RelativePath}");
    options.DescribeAllEnumsAsStrings();
});

app.UseSwaggerUI(options =>
{
    options.SwaggerEndpoint(_appConfiguration["App:HostApiSwaggerEndPoint"], "Host API v1");
    options.SwaggerEndpoint(_appConfiguration["App:TenantApiSwaggerEndPoint"], "Tenant API v1");
    //...
});

However, when I decorate my AppService classes with [ApiExplorerSettings(GroupName = "HostApiv1")], the grouping is ignored and the tag (AppService controller), along with all of its operations (actions / methods), still appear under both documents.

Any idea what is wrong, or how I can debug it?

Answer 1

Swashbuckle depends on ApiExplorer, and the use of the ApiExplorer attribute limits us to specifying only a single groupname per controller / action. ABP service proxies are generated via NSwag for angular project, and it seems that during this process a dependency is broken.

The workaround is to create a custom Attribute for delimiting one-or-more groupnames for an appservice controller or action, and subsequently use reflection in the DocInclusionPredicateFunction option to retrieve the groupnames for an action or its containing controller.

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true)]
public class SwaggerDocAttribute: Attribute
{
    public SwaggerDocAttribute(params string[] includeInDocuments)
    {
        IncludeInDocuments = includeInDocuments;
    }

    public string[] IncludeInDocuments { get; }
}

options.DocInclusionPredicate((docName, apiDesc) =>
{
    if (!apiDesc.ActionDescriptor.IsControllerAction())
    {
        return false;
    }

    apiDesc.TryGetMethodInfo(out MethodInfo methodInfo);

    var actionDocs = methodInfo.GetCustomAttributes<SwaggerDocAttribute>()
        .SelectMany(a => a.IncludeInDocuments);

    var controllerDocs = methodInfo.DeclaringType.GetCustomAttributes<SwaggerDocAttribute>()
        .SelectMany(a => a.IncludeInDocuments);

    switch (docName)
    {
        case "HostApiv1":
            return apiDesc.GroupName == null || 
            actionDocs.Contains("HostApiv1") || 
            controllerDocs.Contains("HostApiv1");
        case "TenantApiv1":
            return apiDesc.GroupName == null ||
            actionDocs.Contains("TenantApiv1") || 
            controllerDocs.Contains("TenantApiv1");
        default:
            return true;
    }
});

Usage

[DisableAuditing]
[AbpAuthorize(AppPermissions.HostSpecific.Dashboard.Access)]
//[ApiExplorerSettings(GroupName = "HostApiv1")] // <== Don't use this
[SwaggerDoc("HostApiv1")] // <== Use this in stead
public class MyDemoAppService : ZenDetectAppServiceBase, IHostDashboardAppService
{
        //...
}