Support for multipart/form-data requests (including files)

[tmenier]

mulipart/form-data requests will be supported in Flurl.Http 1.0 via the following syntax:

var resp = await "http://api.com"
    .PostMultipartAsync(mp => mp
        .AddString("name", "hello!")                // individual string
        .AddStringParts(new {a = 1, b = 2})         // multiple strings
        .AddFile("file1", path1)                    // local file path
        .AddFile("file2", stream, "foo.txt")        // file stream
        .AddJson("json", new { foo = "x" })         // json
        .AddUrlEncoded("urlEnc", new { bar = "y" }) // URL-encoded                      
        .Add(content));                             // any HttpContent

In the above example, mp is a CapturedMultiplartContent, which can be built fluently inline as shown, or separately. It contains a read-only Parts array of HttpContent objects that have been added, which can later be inspected.

[tmenier]

This feature is now available in the latest prerelease:

https://www.nuget.org/packages/Flurl.Http/1.0.0-beta8

[ecentinela]

Hi @tmenier , fantastic! Can you post an example about preparing the CapturedMultipartContent separately? Thanks!

[tmenier]

@ecentinela

var content = new CapturedMultipartContent()
   .Add......

await new FlurlClient(url).SendAsync(HttpMethod.Post, content);

// or

await "http://api.com".WithClient(fc).SendAsync(HttpMethod.Post, content);

[tmenier]

@ecentinela The sample above made me realize there ought to be extension methods on string and Url to match FlurlClient's SendAsync. Further, the overloads of PostAsync, PutAsync, and PatchAsync that took no content argument now take a (nullable) HttpContent object, since those verbs normally have some sort of body.

So, in the previous example, you can now build CapturedMultipartContent and simply post it like this:

await "http://api.com".PostAsync(content);

I did a beta9 for this if you want to test it, but I won't delay the full 1.0 release much longer.

https://www.nuget.org/packages/Flurl.Http/1.0.0-beta9

[eestein]

@tmenier I'm trying to upload a file with some body. Is PostMultipartAsync the only way?

On my C# code I have this:

var resource = FormBind<StorageFileResource>();
var file = Request.Files.First().ToPostedFile();

FormBind reads data from the request and fills the object.

By using PostMultipartAsync I know it should start like this:

.PostMultipartAsync((mp) => { mp.AddFile(name, stream, name)}), but I can't figure out how to add the object. Do you have any ideas on that?

This is my current try:

public static async Task<T> PostFileAsync<T>(string url, object data, string name, Stream stream, object queryString = null)
	where T : class
{
	return await HandleRequest(async () => queryString != null
		? await url
			.SetQueryParams(queryString)
			.SetClaimsToken()
	                           .PostMultipartAsync((mp) => { mp.AddFile(name, stream, name)})
		  	.ReceiveJson<T>()
		: await url
			.SetClaimsToken()
			.PostMultipartAsync((mp) => mp.AddFile(name, stream, name))
		 	.ReceiveJson<T>());
}