Tcl

Send a Staged REST Request with a Streamed Body

Demonstrates Rest.SendReqStreamBody, which sends a request whose body is read from a Stream, then reads the response in separate steps.

The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background. The staged request model separates sending from reading: a SendReq method transmits the request, ReadResponseHeader reads the status line and headers, and a ReadResp method reads the body. This gives fine control over large or streamed messages compared with the single-call full-request methods.

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Tcl


load ./chilkat.dll

set success 0

set rest [new_CkRest]

set bTls 1
set bAutoReconnect 1
set success [CkRest_Connect $rest "example.com" 443 $bTls $bAutoReconnect]
if {$success == 0} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    exit
}

#  The file paths are relative to the application's current working directory.  Absolute paths
#  may also be used.  Supply the paths appropriate to your own environment.

#  The request body is read from a Stream whose source is a local file.
set bodyStream [new_CkStream]

CkStream_put_SourceFile $bodyStream "qa_data/upload.json"

CkRest_AddHeader $rest "Content-Type" "application/json"

#  Send the request, reading the body from the stream.  The 3rd argument is the Stream.
set success [CkRest_SendReqStreamBody $rest "POST" "/api/upload" $bodyStream]
if {$success == 0} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    delete_CkStream $bodyStream
    exit
}

#  After sending, read the response status line and header fields.  The return value is the HTTP
#  status code, or -1 if no response was received.
set statusCode [CkRest_ReadResponseHeader $rest]
if {$statusCode < 0} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    delete_CkStream $bodyStream
    exit
}

puts "Response status code: $statusCode"

#  Read the response body as text.
set responseBody [CkRest_readRespBodyString $rest]
if {[CkRest_get_LastMethodSuccess $rest] == 0} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    delete_CkStream $bodyStream
    exit
}

puts "$responseBody"

delete_CkRest $rest
delete_CkStream $bodyStream