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SharePoint -- Get Server Form Digest Value

Demonstrates how to get a server form digest value to be placed in the X-RequestDigest HTTP request header for POST, PUT, MERGE, and DELETE requests. A form digest value is typically valid for 1800 seconds (i.e. 30 minutes). This example persists the value to a file, and only requests a new form digest value if the existing one is near expiration. AutoIt

Local $bSuccess = False

; This requires the Chilkat API to have been previously unlocked.
; See Global Unlock Sample for sample code.

; First, let's see if we already have a persisted form digest value
; that hasn't yet expired.
$oFac = ObjCreate("Chilkat.FileAccess")
$oXml = ObjCreate("Chilkat.Xml")

; My example code (below) persists the form digest XML in this format:
; 
; 	<savedFormDigestValue>
; 	<d:ExpireDateTime>2017-04-12T20:46:39Z</d:ExpireDateTime>
; 	<d:FormDigestValue>0x3059FFB920651834540F3E6792EA73F5746B302E953FF4E808E485DB1E6C2836C7CF924644995F092453B02A94DE14A7962674B7B16780AF16EAFB8C246BCDC7,12 Apr 2017 17:08:22 -0000</d:FormDigestValue>
; 	</savedFormDigestValue>
; 

$oDtExpire = ObjCreate("Chilkat.CkDateTime")
$oDtNow = ObjCreate("Chilkat.CkDateTime")

Local $sFormDigestXmlFile = "qa_data/sharepoint/savedFormDigestValue.xml"
If ($oFac.FileExists($sFormDigestXmlFile) = True) Then

    $oXml.LoadXmlFile($sFormDigestXmlFile)

    ; Get the expire date/time
    $oDtExpire.SetFromTimestamp($oXml.GetChildContent("d:ExpireDateTime"))

    ; Get the current date/time
    $oDtNow.SetFromCurrentSystemTime()

    ; Get both times as Unix time values
Local $iTNow = $oDtNow.GetAsUnixTime(False)
Local $iTExpire = $oDtExpire.GetAsUnixTime(False)

    ; If tNow >= tExpire, then fall through.
    ; Otherwise, just use the cached digest value.
    If ($iTNow < $iTExpire) Then
        ConsoleWrite("Cached digest value is not yet expired." & @CRLF)
        ConsoleWrite("X-RequestDigest: " & $oXml.GetChildContent("d:FormDigestValue") & @CRLF)
        Exit
    EndIf

EndIf

; If we got to this point, the cached digest value either does not exist, or expired.

$oHttp = ObjCreate("Chilkat.Http")

; If SharePoint Windows classic authentication is used, then set the 
; Login, Password, LoginDomain, and NtlmAuth properties.
$oHttp.Login = "SHAREPOINT_USERNAME"
$oHttp.Password = "SHAREPOINT_PASSWORD"
$oHttp.LoginDomain = "SHAREPOINT_NTLM_DOMAIN"
$oHttp.NtlmAuth = True

; The more common case is to use SharePoint Online authentication (via the SPOIDCRL cookie).
; If so, do not set Login, Password, LoginDomain, and NtlmAuth, and instead
; establish the cookie as shown at SharePoint Online Authentication

; When creating, updating, and deleting SharePoint entities, we'll need
; to first get the server's form digest value to send in the X-RequestDigest header.
; This can be retrieved by making a POST request with an empty body to
; http://<site url>/_api/contextinfo and extracting the value of the
; d:FormDigestValue node in the XML that the contextinfo endpoint returns.

; Apparently, SharePoint needs an "Accept" request header equal to "application/xml",
; otherwise SharePoint will return an utterly incomprehensible and useless error message.
Local $savedAccept = $oHttp.Accept
$oHttp.Accept = "application/xml"

; Note: The last argument ("utf-8") is meaningless here because the body is empty.
$oResp = ObjCreate("Chilkat.HttpResponse")
$bSuccess = $oHttp.HttpStr("POST","https://SHAREPOINT_HTTPS_DOMAIN/_api/contextinfo","","utf-8","application/xml",$oResp)
If ($bSuccess = False) Then
    ConsoleWrite($oHttp.LastErrorText & @CRLF)
    Exit
EndIf

; Restore the default Accept header
$oHttp.Accept = $savedAccept

If ($oResp.StatusCode <> 200) Then
    ; A response status code not equal to 200 indicates failure.
    ConsoleWrite("Response status code = " & $oResp.StatusCode & @CRLF)
    ConsoleWrite("Response body:" & @CRLF)
    ConsoleWrite($oResp.BodyStr & @CRLF)
    Exit
EndIf

$oXml.LoadXml($oResp.BodyStr)

; The response XML looks like this:

; <?xml version="1.0" encoding="utf-8" ?>
; <d:GetContextWebInformation xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns:georss="http://www.georss.org/georss" xmlns:gml="http://www.opengis.net/gml" m:type="SP.ContextWebInformation">
;     <d:FormDigestTimeoutSeconds m:type="Edm.Int32">1800</d:FormDigestTimeoutSeconds>
;     <d:FormDigestValue>0x3059FFB920651834540F3E6792EA73F5746B302E953FF4E808E485DB1E6C2836C7CF924644995F092453B02A94DE14A7962674B7B16780AF16EAFB8C246BCDC7,12 Apr 2017 17:08:22 -0000</d:FormDigestValue>
;     <d:LibraryVersion>15.0.4569.1000</d:LibraryVersion>
;     <d:SiteFullUrl>https://SHAREPOINT_HTTPS_DOMAIN</d:SiteFullUrl>
;     <d:SupportedSchemaVersions m:type="Collection(Edm.String)">
;         <d:element>14.0.0.0</d:element>
;         <d:element>15.0.0.0</d:element>
;     </d:SupportedSchemaVersions>
;     <d:WebFullUrl>https://SHAREPOINT_HTTPS_DOMAIN</d:WebFullUrl>
; </d:GetContextWebInformation>
; 

; Cache the digest value, and also an expiration time.  If this code is run again
; before the digest expires, we'll just get it from the file.
$oXml2 = ObjCreate("Chilkat.Xml")

$oXml2.Tag = "savedFormDigestValue"
$oXml2.NewChild2 "d:FormDigestValue",$oXml.GetChildContent("d:FormDigestValue")

Local $iTimeoutInSec = $oXml.GetChildIntValue("d:FormDigestTimeoutSeconds")
ConsoleWrite("Timeout in seconds = " & $iTimeoutInSec & @CRLF)

; Convert this to an expire timestamp.
; Let's make it expire 30 seconds prior to the actual timeout, just to be safe.
If ($iTimeoutInSec > 30) Then
    $iTimeoutInSec = $iTimeoutInSec - 30
EndIf

$oDtExpire.SetFromCurrentSystemTime()
$oDtExpire.AddSeconds($iTimeoutInSec)
$oXml2.NewChild2 "d:ExpireDateTime",$oDtExpire.GetAsTimestamp(False)

; Persist the digest and expire time to a file.
$oXml2.SaveXml($sFormDigestXmlFile)

ConsoleWrite("Here is the new form digest value:" & @CRLF)
ConsoleWrite("X-RequestDigest: " & $oXml.GetChildContent("d:FormDigestValue") & @CRLF)