PureBasic
PureBasic
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.Chilkat PureBasic Downloads
IncludeFile "CkHttp.pb"
IncludeFile "CkXml.pb"
IncludeFile "CkHttpResponse.pb"
IncludeFile "CkFileAccess.pb"
IncludeFile "CkDateTime.pb"
Procedure ChilkatExample()
success.i = 0
; 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.
fac.i = CkFileAccess::ckCreate()
If fac.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
xml.i = CkXml::ckCreate()
If xml.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
; 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>
;
dtExpire.i = CkDateTime::ckCreate()
If dtExpire.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
dtNow.i = CkDateTime::ckCreate()
If dtNow.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
formDigestXmlFile.s = "qa_data/sharepoint/savedFormDigestValue.xml"
If CkFileAccess::ckFileExists(fac,formDigestXmlFile) = 1
CkXml::ckLoadXmlFile(xml,formDigestXmlFile)
; Get the expire date/time
CkDateTime::ckSetFromTimestamp(dtExpire,CkXml::ckGetChildContent(xml,"d:ExpireDateTime"))
; Get the current date/time
CkDateTime::ckSetFromCurrentSystemTime(dtNow)
; Get both times as Unix time values
tNow.i = CkDateTime::ckGetAsUnixTime(dtNow,0)
tExpire.i = CkDateTime::ckGetAsUnixTime(dtExpire,0)
; If tNow >= tExpire, then fall through.
; Otherwise, just use the cached digest value.
If tNow < tExpire
Debug "Cached digest value is not yet expired."
Debug "X-RequestDigest: " + CkXml::ckGetChildContent(xml,"d:FormDigestValue")
CkFileAccess::ckDispose(fac)
CkXml::ckDispose(xml)
CkDateTime::ckDispose(dtExpire)
CkDateTime::ckDispose(dtNow)
ProcedureReturn
EndIf
EndIf
; If we got to this point, the cached digest value either does not exist, or expired.
http.i = CkHttp::ckCreate()
If http.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
; If SharePoint Windows classic authentication is used, then set the
; Login, Password, LoginDomain, and NtlmAuth properties.
CkHttp::setCkLogin(http, "SHAREPOINT_USERNAME")
CkHttp::setCkPassword(http, "SHAREPOINT_PASSWORD")
CkHttp::setCkLoginDomain(http, "SHAREPOINT_NTLM_DOMAIN")
CkHttp::setCkNtlmAuth(http, 1)
; 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.
savedAccept.s = CkHttp::ckAccept(http)
CkHttp::setCkAccept(http, "application/xml")
; Note: The last argument ("utf-8") is meaningless here because the body is empty.
resp.i = CkHttpResponse::ckCreate()
If resp.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkHttp::ckHttpStr(http,"POST","https://SHAREPOINT_HTTPS_DOMAIN/_api/contextinfo","","utf-8","application/xml",resp)
If success = 0
Debug CkHttp::ckLastErrorText(http)
CkFileAccess::ckDispose(fac)
CkXml::ckDispose(xml)
CkDateTime::ckDispose(dtExpire)
CkDateTime::ckDispose(dtNow)
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
ProcedureReturn
EndIf
; Restore the default Accept header
CkHttp::setCkAccept(http, savedAccept)
If CkHttpResponse::ckStatusCode(resp) <> 200
; A response status code not equal to 200 indicates failure.
Debug "Response status code = " + Str(CkHttpResponse::ckStatusCode(resp))
Debug "Response body:"
Debug CkHttpResponse::ckBodyStr(resp)
CkFileAccess::ckDispose(fac)
CkXml::ckDispose(xml)
CkDateTime::ckDispose(dtExpire)
CkDateTime::ckDispose(dtNow)
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
ProcedureReturn
EndIf
CkXml::ckLoadXml(xml,CkHttpResponse::ckBodyStr(resp))
; 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.
xml2.i = CkXml::ckCreate()
If xml2.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
CkXml::setCkTag(xml2, "savedFormDigestValue")
CkXml::ckNewChild2(xml2,"d:FormDigestValue",CkXml::ckGetChildContent(xml,"d:FormDigestValue"))
timeoutInSec.i = CkXml::ckGetChildIntValue(xml,"d:FormDigestTimeoutSeconds")
Debug "Timeout in seconds = " + Str(timeoutInSec)
; Convert this to an expire timestamp.
; Let's make it expire 30 seconds prior to the actual timeout, just to be safe.
If timeoutInSec > 30
timeoutInSec = timeoutInSec - 30
EndIf
CkDateTime::ckSetFromCurrentSystemTime(dtExpire)
CkDateTime::ckAddSeconds(dtExpire,timeoutInSec)
CkXml::ckNewChild2(xml2,"d:ExpireDateTime",CkDateTime::ckGetAsTimestamp(dtExpire,0))
; Persist the digest and expire time to a file.
CkXml::ckSaveXml(xml2,formDigestXmlFile)
Debug "Here is the new form digest value:"
Debug "X-RequestDigest: " + CkXml::ckGetChildContent(xml,"d:FormDigestValue")
CkFileAccess::ckDispose(fac)
CkXml::ckDispose(xml)
CkDateTime::ckDispose(dtExpire)
CkDateTime::ckDispose(dtNow)
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
CkXml::ckDispose(xml2)
ProcedureReturn
EndProcedure