Content type multipart form data

The problem with multipart form-data is that the boundary separator must not be present in the file data (see RFC 2388; section also includes a rather lame excuse for not having a proper aggregate MIME type that avoids this problem). RFC1867] The multipart/ form-data content type is intended to allow information providers to express file upload requests uniformly, and to provide a MIME-compatible representation for file upload responses. In a multipart form-data body, the HTTP Content-Disposition general header is a header that can be used on the subpart of a multipart body to give information about the field it applies to.

The subpart is delimited by the boundary defined in the Content-Type header. Used on the body itself, Content-Disposition has no effect. Multipart form data To begin with, posting purchase order acknowledgements (POA’s) and invoices to the API requires a “ multipart format data ” payload.

See this link for technical information about this encoding. The body must then contain one or more body parts, each preceded by an encapsulation boundary, and the last one followed by a closing boundary. If you are accessing an external API, this is probably always the case.

Unfortunately, building this post using C# is not quite as straightforward. I first tried using the WebClient UploadFile metho but it didn’t fit my needs because I wanted to upload form values (i filename, other API specific parameters) in addition to just a file. This form contains a text input control and a file input control. When a form contains a file input control, the enctype attribute should always be multipart form-data , which specifies that the form will be sent as a multipart MIME message. The enctype attribute specifies how the form-data should be encoded when submitting it to the server.

The Content - Type entity header is used to indicate the media type of the resource. In responses, a Content - Type header tells the client what the content type of the returned content actually is. Browsers will do MIME sniffing in some cases and will not necessarily follow the value of this header; to prevent this behavior,.