Xbase++

Building a multipart/form-data Request for HTTP Upload

See more HTTP Examples

Uploading files to a web server typically requires building a multipart/form-data request where the files are contained in the sub-parts of the MIME request.

Note: HTTP uploads require code on the server-side to receive the upload. For example, see Complete C# ASP.NET HTTP Upload Example

This example produces the following HTTP multipart/form-data request:

POST /something HTTP/1.1
Content-Type: multipart/form-data; boundary=------------070002080409050901090203
Host: domain
Content-Length: 546

--------------070002080409050901090203
Content-Disposition: form-data; name="fileA"; filename="fileA.txt"
Content-Type: text/plain

This is the contents of file A
--------------070002080409050901090203
Content-Disposition: form-data; name="fileB"; filename="fileB.txt"
Content-Type: text/plain

This is the contents of file B
--------------070002080409050901090203
Content-Disposition: form-data; name="fileC"; filename="fileC.txt"
Content-Type: text/plain

This is the contents of file C
--------------070002080409050901090203--

Xbase++

LOCAL oReq
LOCAL cRequestMime

//  This example demonstrates building a multipart/form-data request.

oReq := CreateObject("Chilkat.HttpRequest")

//  The ContentType, HttpVerb, and Path properties should
//  always be explicitly set.
oReq:HttpVerb := "POST"
oReq:Path := "/something"
oReq:ContentType := "multipart/form-data"

//  The contents and name of each file to be uploaded is provided
//  by calling any of the following methods:
//  AddBytesForUpload
//  AddBytesForUpload2
//  AddFileForUpload
//  AddFileForUpload2
//  AddStringForUpload
//  AddStringForUpload2

//  For this example, we'll provide the contents of the files to be uploaded
//  directly as in-memory strings.
oReq:AddStringForUpload("fileA", "fileA.txt", "This is the contents of file A", "utf-8")
oReq:AddStringForUpload("fileB", "fileB.txt", "This is the contents of file B", "utf-8")
oReq:AddStringForUpload("fileC", "fileC.txt", "This is the contents of file C", "utf-8")

//  View the request that would be sent if HttpSReq was called:
cRequestMime := oReq:GenerateRequestText()
? cRequestMime

//  A few important comments about the HTTP request that is generated:
//  
//  1) Chilkat automatically generates a random boundary string.   In 99.999% of cases, this should 
//     be sufficient.
//  2) The Content-Length header is automatically generated based on the actual length of the MIME message
//     that follows the intial (topmost) MIME header.
//  3) The HOST header will automatically get filled in with the actual domain when HttpSReq
//     is called.

oReq:destroy()