(AutoIt) curl with Variable Substitution in a JSON Request Body

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This example shows how to use variables inside a JSON request body using the {{variable_name}} syntax. When the HTTP request’s Content-Type indicates JSON, Chilkat automatically applies proper JSON escaping to each substituted value, ensuring the resulting JSON remains valid.

Note: This example requires Chilkat v11.5.0 or greater.

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Local $bSuccess = False

; Variable names are enclosed between {{ and }}
; Important: The variable {{var_name}} should be placed inside the quotes.

; This is correct:
; curl -X POST https://api.example.com/messages \
;   -H "Content-Type: application/json" \
;   -d '{"text":"{{message}}"}'

; This is incorrect:
;   -d '{"text":{{message}}}'

$oSbCurl = ObjCreate("Chilkat.StringBuilder")
$oSbCurl.AppendLn("curl -X POST https://api.example.com/messages \")
$oSbCurl.AppendLn("  -H ""Content-Type: application/json"" \")
$oSbCurl.AppendLn("  -d '{""text"":""{{message}}""}'")

$oCurl = ObjCreate("Chilkat.HttpCurl")

; In this example, the value we'll provide for the "message" variable
; will contain chars that require JSON escaping.
$oCurl.SetVar "message","He said ""Hello, world!"""

; To demonstrate how the variables are replaced, this example does not execute the curl command. 
; Instead, it generates the raw HTTP request that would be sent if the curl command were run.
$oSbRawRequest = ObjCreate("Chilkat.StringBuilder")
$bSuccess = $oCurl.ToRawRequest($oSbCurl.GetAsString(),$oSbRawRequest)
If ($bSuccess = False) Then
    ConsoleWrite($oCurl.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite($oSbRawRequest.GetAsString() & @CRLF)

; The output is shown below.
; Notice that the quote chars around "Hello World!" are properly JSON escaped.

; POST /messages HTTP/1.1
; Host: api.example.com
; Content-Type: application/json
; Content-Length: 36
; 
; {"text":"He said \"Hello, world!\""}