DataFlex
DataFlex
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 DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
Handle hoFac
Handle hoXml
Handle hoDtExpire
Handle hoDtNow
String sFormDigestXmlFile
Integer iTNow
Integer iTExpire
Handle hoHttp
String sSavedAccept
Variant vResp
Handle hoResp
Handle hoXml2
Integer iTimeoutInSec
String sTemp1
Integer iTemp1
Boolean bTemp1
Move False To iSuccess
// 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.
Get Create (RefClass(cComCkFileAccess)) To hoFac
If (Not(IsComObjectCreated(hoFac))) Begin
Send CreateComObject of hoFac
End
Get Create (RefClass(cComChilkatXml)) To hoXml
If (Not(IsComObjectCreated(hoXml))) Begin
Send CreateComObject of hoXml
End
// 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>
//
Get Create (RefClass(cComCkDateTime)) To hoDtExpire
If (Not(IsComObjectCreated(hoDtExpire))) Begin
Send CreateComObject of hoDtExpire
End
Get Create (RefClass(cComCkDateTime)) To hoDtNow
If (Not(IsComObjectCreated(hoDtNow))) Begin
Send CreateComObject of hoDtNow
End
Move "qa_data/sharepoint/savedFormDigestValue.xml" To sFormDigestXmlFile
Get ComFileExists Of hoFac sFormDigestXmlFile To bTemp1
If (bTemp1 = True) Begin
Get ComLoadXmlFile Of hoXml sFormDigestXmlFile To iSuccess
// Get the expire date/time
Get ComGetChildContent Of hoXml "d:ExpireDateTime" To sTemp1
Get ComSetFromTimestamp Of hoDtExpire sTemp1 To iSuccess
// Get the current date/time
Get ComSetFromCurrentSystemTime Of hoDtNow To iSuccess
// Get both times as Unix time values
Get ComGetAsUnixTime Of hoDtNow False To iTNow
Get ComGetAsUnixTime Of hoDtExpire False To iTExpire
// If tNow >= tExpire, then fall through.
// Otherwise, just use the cached digest value.
If (iTNow < iTExpire) Begin
Showln "Cached digest value is not yet expired."
Get ComGetChildContent Of hoXml "d:FormDigestValue" To sTemp1
Showln "X-RequestDigest: " sTemp1
Procedure_Return
End
End
// If we got to this point, the cached digest value either does not exist, or expired.
Get Create (RefClass(cComChilkatHttp)) To hoHttp
If (Not(IsComObjectCreated(hoHttp))) Begin
Send CreateComObject of hoHttp
End
// If SharePoint Windows classic authentication is used, then set the
// Login, Password, LoginDomain, and NtlmAuth properties.
Set ComLogin Of hoHttp To "SHAREPOINT_USERNAME"
Set ComPassword Of hoHttp To "SHAREPOINT_PASSWORD"
Set ComLoginDomain Of hoHttp To "SHAREPOINT_NTLM_DOMAIN"
Set ComNtlmAuth Of hoHttp To 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.
Get ComAccept Of hoHttp To sSavedAccept
Set ComAccept Of hoHttp To "application/xml"
// Note: The last argument ("utf-8") is meaningless here because the body is empty.
Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
If (Not(IsComObjectCreated(hoResp))) Begin
Send CreateComObject of hoResp
End
Get pvComObject of hoResp to vResp
Get ComHttpStr Of hoHttp "POST" "https://SHAREPOINT_HTTPS_DOMAIN/_api/contextinfo" "" "utf-8" "application/xml" vResp To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoHttp To sTemp1
Showln sTemp1
Procedure_Return
End
// Restore the default Accept header
Set ComAccept Of hoHttp To sSavedAccept
Get ComStatusCode Of hoResp To iTemp1
If (iTemp1 <> 200) Begin
// A response status code not equal to 200 indicates failure.
Get ComStatusCode Of hoResp To iTemp1
Showln "Response status code = " iTemp1
Showln "Response body:"
Get ComBodyStr Of hoResp To sTemp1
Showln sTemp1
Procedure_Return
End
Get ComBodyStr Of hoResp To sTemp1
Get ComLoadXml Of hoXml sTemp1 To iSuccess
// 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.
Get Create (RefClass(cComChilkatXml)) To hoXml2
If (Not(IsComObjectCreated(hoXml2))) Begin
Send CreateComObject of hoXml2
End
Set ComTag Of hoXml2 To "savedFormDigestValue"
Get ComGetChildContent Of hoXml "d:FormDigestValue" To sTemp1
Send ComNewChild2 To hoXml2 "d:FormDigestValue" sTemp1
Get ComGetChildIntValue Of hoXml "d:FormDigestTimeoutSeconds" To iTimeoutInSec
Showln "Timeout in seconds = " iTimeoutInSec
// 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) Begin
Move (iTimeoutInSec - 30) To iTimeoutInSec
End
Get ComSetFromCurrentSystemTime Of hoDtExpire To iSuccess
Get ComAddSeconds Of hoDtExpire iTimeoutInSec To iSuccess
Get ComGetAsTimestamp Of hoDtExpire False To sTemp1
Send ComNewChild2 To hoXml2 "d:ExpireDateTime" sTemp1
// Persist the digest and expire time to a file.
Get ComSaveXml Of hoXml2 sFormDigestXmlFile To iSuccess
Showln "Here is the new form digest value:"
Get ComGetChildContent Of hoXml "d:FormDigestValue" To sTemp1
Showln "X-RequestDigest: " sTemp1
End_Procedure