HTTPClient POST with Multipart Form

Resolved HTTPClient POST with Multipart Form

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Clint Maxwell
PowerBuilder
Tuesday, 13 March 2018 01:34 AM UTC

Similar to a question asked earlier, I'm trying to call a REST service to send a file. Need to know if its possible and what it would look like to set up HTTPClient to execute a multipart POST request containing 3 parts (2 strings and a blob).

Accepted Answer

René Ullrich Accepted Answer Pending Moderation

Tuesday, 13 March 2018 07:24 AM UTC
PowerBuilder
# Permalink

I use MS XMLHTTP ActiveX but I guess it's almost the same with PB HTTPClient.

You have to build the request body and include all data:

// ls_xml this is my xml as part of the content

// lblob_file is a file as part of the content

// ls_mimetype is the mimetype of the file

ls_BOUNDARY = "$$$Boundary$$$" // use or build a string that is not part of the other content!

// build the content

lblob_data = blob ("--" + ls_BOUNDARY + "~r~n" + & 'Content-Disposition: form-data; name="meta"' + & "~r~n~r~n" + ls_xml + "~r~n", EncodingUTF8!)

lblob_data = lblob_data + blob ("--" + ls_BOUNDARY + "~r~n" + & 'Content-Disposition: form-data; name="file"; filename="' + as_filename + '"' + & "~r~nContent-Type: " + ls_mimetype + "~r~n~r~n", EncodingUTF8!) + & lblob_file + blob ("~r~n--" + ls_BOUNDARY + "--~r~n", EncodingUTF8!)

you have to set the content type in the request header and also the boundary

// with MS XMLHTTP:

lole_XmlHttp.setRequestHeader ("Content-Type", "multipart/form-data; boundary=" + ls_BOUNDARY)

Comment

Clint Maxwell
Tuesday, 13 March 2018 19:00 PM UTC

Thanks René!

With your example above I was able to put it together and get it working. Knowing that it it was just a blob of other blobs did the trick. An example using HTTPClient is below.

// Read the file into a blob

ll_FileNum = FileOpen('TEST.PDF', StreamMode!)

FileReadEx(ll_FileNum, blb_file)

FileClose(ll_FileNum)

ls_FileName = 'TEST.PDF'

ls_MimeType = 'application/pdf'

// Create a boundary marker for the multipart blob

ls_BOUNDARY = "$$$Boundary$$$"

// Create component blobs

blb_boundary = blob('~r~n--' + ls_Boundary + '~r~n', EncodingUTF8!)

blb_terminus = blob('~r~n--' + ls_Boundary + '--~r~n', EncodingUTF8!)

blb_filename = blob('Content-Disposition: form-data; name="File-Name"' + '~r~n~r~n' + ls_FileName, EncodingUTF8!)

blb_mimetype = blob('Content-Disposition: form-data; name="Mime-Type"' + '~r~n~r~n' + ls_MimeType, EncodingUTF8!)

blb_file = blob( 'Content-Disposition: form-data; name="File"; filename="' + ls_FileName + '"' + '~r~n' + &

"Content-Type: " + ls_MimeType + "~r~n~r~n", EncodingUTF8!) + &

  blb_file

// Concatenate blobs into a single multipart blob

blb_multipart = blb_boundary + &

blb_filename + &

  blb_boundary + &

  blb_mimetype + &

  blb_boundary + &

  blb_file + &

  blb_terminus

// HTTPClient

inv_httpClient.clearrequestheaders()

inv_httpClient.setrequestheader('Access-Token', sle_access_token.text)

inv_httpClient.SetRequestHeader("Content-Type", "multipart/form-data; boundary=" + ls_BOUNDARY)

inv_httpClient.SendRequest('POST', ls_url, blb_multipart)

inv_httpClient.GetResponseBody(ls_json)

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Responses (2)

Alfredo Santibanez Accepted Answer Pending Moderation

Tuesday, 6 October 2020 21:33 PM UTC
PowerBuilder
# 1

Hi Renee, I am trying to make a token request to azure using that works in Postman, but cannot make it from PB.

I tried using loo_xmlhttp.ConnectToNewObject("Msxml2.XMLHTTP.6.0") and HttpClient with the same result

The content from postman is:

 
Request Body:grant_type:"client_credentials"
client_id:"xxxxxxxxxxxxxxxxxxxxx"
client_secret:"xxxxxx"
scope:"https://apixxx.azurewebsites.net/.default"

I tried filling the variable like this:

s_BOUNDARY = "$$$Boundary$$$"
body="grant_type:~"client_credentials~""+char(10)+&
"client_id:~"xxxxxxxxxxxxxxxxx~""+char(10)+&
"client_secret:~"xxxxxxxxxxxxxxxxxxxxx""+char(10)+&
"scope:~"https://apiedwh.azurewebsites.net/.default~""

lblob_data = blob ("--" + ls_BOUNDARY + "~r~n" + &
"~r~n~r~n" + body + "~r~n", EncodingUTF8!)

lblob_data = lblob_data + blob ("--" + ls_BOUNDARY + "~r~n" , EncodingUTF8!)

    lnv_HttpClient.SetRequestHeader("Content-Type", "multipart/form-data; boundary=--" + ls_BOUNDARY)
   integer li_rc
   li_rc = lnv_HttpClient.SendRequest("POST", requestendpoint,lblob_data)

The result is 400, does not recognize the parameters in the multiform part

Can you give a hint on what to look for.

Best Regards

Alfredo

Comment

René Ullrich
Wednesday, 7 October 2020 06:29 AM UTC

Hi Alfredo,

I can't see why you are using a boundary in your body? Seems to be no such part in Postman request?

Try to simple repeat what Postman sends.

HTH,

René

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