How to allow a file download?

Several of my API methods result in a file download. How can I get Swashbuckle to download a file through the UI for these methods?

I’ve added an IOperationFilter with the following Apply method to add a “produces” attribute to certain methods:

public void Apply(Operation operation, SchemaRegistry schemaRegistry, ApiDescription apiDescription)
{
    if (apiDescription.ID == "GETapi/Templates/{id}")
    {
        operation.produces.Add("application/octet-stream");
    }
}

But when I execute this method through the Swashbuckle UI it displays the file contents in the “Response Body” textarea. Is there a way of getting a file to actually download?

Thanks

[gaui]

Weird, we are having the same problem. We have the latest version of SB 2.4.0. Why is this closed?

We have the following function:

[HttpGet("{id}")]
[ProducesResponseType(typeof(FileStreamResult), 200)]
public async Task<IActionResult> GetFileById(string id)

Which produces the following Swagger Spec:

'/Files/{id}':
get:
  tags:
	- Files
  operationId: FilesByIdGet
  consumes: []
  produces:
	- text/plain
	- application/json
	- text/json
  parameters:
	- name: id
	  in: path
	  required: true
	  type: string
  responses:
	'200':
	  description: Success
	  schema:
		$ref: '#/definitions/FileStreamResult'

This is not correct, so when I generate a client with AutoRest or NSwag, it tries to serialize the data as JSON.

I monkey patched it with this operation filter and it works fine:

public class SwaggerFileOperationFilter : IOperationFilter
{
	public void Apply(Operation operation, OperationFilterContext context)
	{
		var anyFileStreamResult = context.ApiDescription.SupportedResponseTypes
			.Any(x => x.Type == typeof(FileStreamResult));

		if (anyFileStreamResult)
		{
			operation.Produces = new[] { "application/octet-stream" };
			operation.Responses["200"].Schema = new Schema { Type = "file" };
		}
	}
}

[domaindrivendev]

@centur - you can wire up an IOperationFilter (see readme for details). It would look something like this …

public class UpdateFileDownloadOperations : IOperationFilter
{
    public void Apply(Operation operation, SchemaRegistry schemaRegistry, ApiDescription apiDescription)
    {
        if (operation.operationId == "FileDownload_GetFile")
        {
            operation.produces = new[] { "application/octet-stream" };
            operation.responses["200"].schema = new Schema { type = "file" };
        }
    }
}

I’ve used this to create a valid spec, but it seems the UI still doesn’t support the downloads yet …