Custom Azure API Apps for Files

Question

I'm looking to create some custom API apps for the sole purpose of creating a/some Logic Apps. With these custom API Apps, I want to pass around files. These files will usually be CSV, ZIP, Excel, TXT, and some other formats - unknown to the consumer until the file is returned (i.e. the client does not dictate the file format).

How does one do something like this in a way that's compatible with Swagger/Swashbuckle, Web API, and Logic Apps? I'll ultimately be tying this into an FTP connector, Dropbox, Onebox, or other file-storage connector.

Does following something like this work or do I need to take a different approach? For example, should I simply work with JSON objects and let my binary be base64-encoded by using a model like this?

public class BinaryFile
{
    public string FileName { get; set; }
    public string FileExtension { get; set; }
    public string DeducedMimeType { get; set; }
    public int FileSize { get; set; }
    public string FileEncoding { get; set; }
    public byte[] FileBinary { get; set; }
}

(this question is cross-posted to MSDN Forums)

score 0 · Accepted Answer · answered Jan 05 '16 at 14:45

The approach I've taken is what I posed in the question with the BinaryFile class. I've broken it out into a few classes. I'm not done - I have some improvements to make still but this is functional right now.

Main class with some common fields:

public class FileResult<T>
{
    public string Source { get; set; }
    public T File { get; set; }
    public IList<string> ErrorMessages { get; set; } = new List<string>();
    public bool IsSuccessful { get; set; } = false;
}

This is the <T> in my FileResult<T> class:

public class CsvFile
{
    public string Filename { get; set; }
    public string Contents { get; set; }
    public int Size { get; set; }
}

public class BinaryFile
{
    public string FileName { get; set; }
    public string FileExtension { get; set; }
    public string DeducedMimeType { get; set; }
    public int Size { get; set; }
    public byte[] Contents { get; set; }
}

Note that in my case, there are some times when I am working with multiple files and not just one, so what could appear to be some common fields are still within the type passed in as the <T> so I can have something like FileResult<IEnumerable<CsvFile>>.

This is all playing nicely with Swagger, Swashbuckle, Web API, Azure API Apps, and Azure Logic Apps. For the cases where I am returning multiple files to my Azure Logic App, I use the fairly hidden splitsOn feature (that also has some designer bugs, so be careful!) to easily iterate over all of the files. It works very nicely.

Custom Azure API Apps for Files

1 Answers1