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WinHttp.WinHttpRequest adding to content type

I'm trying to make a request for kigo api using vba WinHttp.WinHttpRequest, I was able to send the request, but WinHttpRequest changes the addition of the content type Charset = UTF-8 when it sends the request, with kigo api returning 415 error.

I set the content type like this

web_Http.SetRequestHeader "Content-Type", "application/json"

but when I look at the request in Wireshark, the content type looks like this:

 Content-Type: application/json; Charset=UTF-8

Any ideas?

I found this one that looks like my problem, but I do not understand the solution.

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I am also facing this problem. It seems to be limited by the WinHttp.WinHttpRequest COM WinHttp.WinHttpRequest . There are several different solutions to this problem.

After some digging, I found this post from a Microsoft employee. It gives a clear explanation and recommends sending to a binary array.

If you use a POSTing string using the WinHttpRequest object, you cannot override how it encodes the string for transmission. A WinHttpRequest object will always convert a Unicode string to UTF-8.

However, note that a Unicode string containing only 7-bit LATIN-1 / ISO-8859-1 characters remains unchanged when encoded as UTF-8 ;-) In such cases, the WinHttpRequest object does not add the attribute "Charset = UTF-8" for your Content-Type header. (And I would think the server would assume that the POST data is ISO-8859-1.)

So, if the XML text data that you use POST contains LATIN-1 alphanumeric or punctuation marks (each is less than the decimal number 128), then all you need to be to specify the encoding "ISO-8859-1" in your Content -Type header:

WinHttpReq.SetRequestHeader "Content-Type", "application/xml;Charset=ISO-8859-1"

However, if your POST data contains 8-bit characters, you cannot provide data as a string for the send method. To avoid UTF-8 conversions, your application should convert the string to an array of bytes and put this instead. The WinHttpRequest object will not attempt to perform any data conversion into an array of bytes.

Hello,

Stephen Sulzer

Microsoft Corporation

The second option, in addition to sending in a binary array, is to switch to Msxml2.XMLHTTP or Msxml2.ServerXMLHTTP . None of them control the Content-Type header. Fortunately, when WinHttp.WinHttpRequest was created, Microsoft intentionally used Msxml2.XMLHTTP as a template for the interface. Thus, it is quite simple to convert the code.

In addition, the Msxml2.ServerXMLHTTP COM interface uses WinHTTP internally . Thus, while you lose access to some functions that are exclusive to WinHttp.WinHttpRequest , both use the same backend.

The third option - to use ADODB.Stream . This allows you to work with IStream , which you usually cannot do with VBA. The code sample below is based on the answer to the question How to create a BinaryArray in VbScript? .

 ' Create a Binary Stream Set objStreamBinary = CreateObject("ADODB.Stream") objStreamBinary.Type = 1 objStreamBinary.Open ' Create a Text Stream Set objStreamText = CreateObject("ADODB.Stream") objStreamText.Type = 2 objStreamText.Open ' Copy the POST data to the Text Stream objStreamText.WriteText strRequest objStreamText.Position = 2 ' Copy the Text Stream Contents to the Binary Stream objStreamText.CopyTo objStreamBinary objStreamText.Close ' Read the contents of the Binary Stream ' and send it to the WinHttpRequest object web_Http.Send objStreamBinary.Read(-1)
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Source: https://habr.com/ru/post/1243903/

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