Http Multipart Parser

Release Notes	NuGet (stable)	MyGet (prerelease)

About

The Http Multipart Parser does it exactly what it claims on the tin: parses multipart/form-data. This particular parser is well suited to parsing large data from streams as it doesn't attempt to read the entire stream at once and procudes a set of streams for file data.

Installation

The easiest way to include HttpMultipartParser in your project is by adding the nuget package to your project:

PM> Install-Package HttpMultipartParser

.NET framework suport

• The parser currently targets .NET Standard 2.0 and .NET 8.0.
• Version 5.1.0 was the last version that supported .NET 4.6.1, NET 4.7.2 and .NET standard 2.0.
• Version 2.2.4 was the last version that supported older .NET platforms such as .NET 4.5 and .NET standard 1.3.

Usage

Non-Streaming (Simple, don't use on very large files)

1. Parse the stream containing the multipart/form-data by invoking MultipartFormDataParser.Parse (or it's asynchronous counterpart MultipartFormDataParser.ParseAsync).
2. Access the data through the parser.

Streaming (Handles large files)

1. Create a new StreamingMultipartFormDataParser with the stream containing the multipart/form-data
2. Set up the ParameterHandler and FileHandler delegates
3. Call parser.Run() (or it's asynchronous counterpart parser.RunAsync())
4. The delegates will be called as data streams in.

Examples

Single file

// stream:
-----------------------------41952539122868
Content-Disposition: form-data; name="username"
example
-----------------------------41952539122868
Content-Disposition: form-data; name="email"
example@data.com
-----------------------------41952539122868
Content-Disposition: form-data; name="files[]"; filename="photo1.jpg"
Content-Type: image/jpeg
ExampleBinaryData012031203
-----------------------------41952539122868--

// ===== Simple Parsing ====// You can parse synchronously:varparser=MultipartFormDataParser.Parse(stream);// Or you can parse asynchronously:varparser=awaitMultipartFormDataParser.ParseAsync(stream).ConfigureAwait(false);// From this point the data is parsed, we can retrieve the// form data using the GetParameterValue method.varusername=parser.GetParameterValue("username");varemail=parser.GetParameterValue("email");// Files are stored in a list:varfile=parser.Files.First();stringfilename=file.FileName;Streamdata=file.Data;// ==== Advanced Parsing ====varparser=newStreamingMultipartFormDataParser(stream);parser.ParameterHandler+= parameter =>DoSomethingWithParameter(parameter);parser.FileHandler+=(name,fileName,type,disposition,buffer,bytes,partNumber,additionalProperties)=>{// Write the part of the file we've received to a file stream. (Or do something else)filestream.Write(buffer,0,bytes);};// You can parse synchronously:parser.Run();// Or you can parse asynchronously:awaitparser.RunAsync().ConfigureAwait(false);

Multiple Parameters

// stream:
-----------------------------41952539122868
Content-Disposition: form-data; name="checkbox"
likes_cake
-----------------------------41952539122868
Content-Disposition: form-data; name="checkbox"
likes_cookies
-----------------------------41952539122868--

// ===== Simple Parsing ====// You can parse synchronously:varparser=MultipartFormDataParser.Parse(stream);// Or you can parse asynchronously:varparser=awaitMultipartFormDataParser.ParseAsync(stream).ConfigureAwait(false);// From this point the data is parsed, we can retrieve the// form data from the GetParameterValues methodvarcheckboxResponses=parser.GetParameterValues("checkbox");foreach(varparameterincheckboxResponses){Console.WriteLine("Parameter {0} is {1}",parameter.Name,parameter.Data)}

Multiple Files

// stream:
-----------------------------41111539122868
Content-Disposition: form-data; name="files[]"; filename="photo1.jpg"
Content-Type: image/jpeg
MoreBinaryData
-----------------------------41111539122868
Content-Disposition: form-data; name="files[]"; filename="photo2.jpg"
Content-Type: image/jpeg
ImagineLotsOfBinaryData
-----------------------------41111539122868--

// ===== Simple Parsing ====// You can parse synchronously:varparser=MultipartFormDataParser.Parse(stream);// Or you can parse asynchronously:varparser=awaitMultipartFormDataParser.ParseAsync(stream).ConfigureAwait(false);// Loop through all the filesforeach(varfileinparser.Files){Streamdata=file.Data;// Do stuff with the data.}// ==== Advanced Parsing ====varparser=newStreamingMultipartFormDataParser(stream);parser.ParameterHandler+= parameter =>DoSomethingWithParameter(parameter);parser.FileHandler+=(name,fileName,type,disposition,buffer,bytes,partNumber,additionalProperties)=>{// Write the part of the file we've received to a file stream. (Or do something else)// Assume that filesreamsByName is a Dictionary<string, FileStream> of all the files// we are writing.filestreamsByName[name].Write(buffer,0,bytes);};parser.StreamClosedHandler+=(){// Do things when my input stream is closed};// You can parse synchronously:parser.Run();// Or you can parse asynchronously:awaitparser.RunAsync().ConfigureAwait(false);

Licensing

This project is licensed under MIT.