Swashbuckle.aspnetcore: How to set the BasePath in v5?

[rgelb]

I tried StackOverflow, but got no answers, so I'll try here.

In v4, I could set the basePath as follows:

app.UseSwagger(c => {
    c.PreSerializeFilters.Add((swaggerDoc, httpReq) => swaggerDoc.BasePath = "/folder/data");
});

In v5, all the classes pertaining to this changed and I am unclear how to replicate the code above. I tried the following, but just don't see where exactly to set the BasePath:

app.UseSwagger(c => {
    c.PreSerializeFilters.Add((swaggerDoc, httpReq) =>
    {
        var paths = new OpenApiPaths();
        var pathItem = new OpenApiPathItem();

        paths.Add("main", pathItem);
        swaggerDoc.Paths = paths;

    });
});

So how does one set a BasePath?

[rsibanez89]

BasePath was used in Swagger v2.0: https://swagger.io/docs/specification/2-0/api-host-and-base-path/
It has been replaced by the servers array in OpenApi v3.0: https://swagger.io/docs/specification/api-host-and-base-path/

In v5 you have to do this for using OpenAapi v3.0:

var basePath = "/v1";
app.UseSwagger(c =>
    {
        c.RouteTemplate = "swagger/{documentName}/swagger.json";
        c.PreSerializeFilters.Add((swaggerDoc, httpReq) =>
        {
            swaggerDoc.Servers = new List<OpenApiServer> { new OpenApiServer { Url = $"{httpReq.Scheme}://{httpReq.Host.Value}{basePath}" } };
        });
    });

but you won't get a basePath property in the json file.

Or this for using Swagger v2.0:

var basePath = "/v1";
app.UseSwagger(c =>
    {
        c.SerializeAsV2 = true;
        c.RouteTemplate = "swagger/{documentName}/swagger.json";
        c.PreSerializeFilters.Add((swaggerDoc, httpReq) =>
        {
            swaggerDoc.Servers = new List<OpenApiServer> { new OpenApiServer { Url = $"{httpReq.Scheme}://{httpReq.Host.Value}{basePath}" } };
        });
    });

And then your basePath will be /v1

[PauloVetor]

I came up with a similar solution, using DocumentFilter:

public class SwaggerDocumentFilter : IDocumentFilter
{
    public void Apply(OpenApiDocument swaggerDoc, DocumentFilterContext context)
    {
        swaggerDoc.Servers.Add(new OpenApiServer() { Url = "/basepath" });
    }
}

and in Startup.cs:

services.AddSwaggerGen(options =>
{
    options.DocumentFilter<SwaggerDocumentFilter>();
});

[lisamariet]

None of these wroked for me. I need to be able to set relative basePath witout setting hostbalue or httpReg scheme. Only setting a relative basePath. Have asked the question here https://stackoverflow.com/questions/61733433/how-do-i-setup-swashbucle-v5-with-swagger-when-i-have-a-custom-base-url