(Android™) 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.

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// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // 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.
    CkFileAccess fac = new CkFileAccess();
    CkXml xml = new CkXml();
    boolean success;

    // 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>
    // 

    CkDateTime dtExpire = new CkDateTime();
    CkDateTime dtNow = new CkDateTime();

    String formDigestXmlFile = "qa_data/sharepoint/savedFormDigestValue.xml";
    if (fac.FileExists(formDigestXmlFile) == true) {

        xml.LoadXmlFile(formDigestXmlFile);

        // Get the expire date/time
        dtExpire.SetFromTimestamp(xml.getChildContent("d:ExpireDateTime"));

        // Get the current date/time
        dtNow.SetFromCurrentSystemTime();

        // Get both times as Unix time values
        int tNow = dtNow.GetAsUnixTime(false);
        int tExpire = dtExpire.GetAsUnixTime(false);

        // If tNow >= tExpire, then fall through.
        // Otherwise, just use the cached digest value.
        if (tNow < tExpire) {
            Log.i(TAG, "Cached digest value is not yet expired.");
            Log.i(TAG, "X-RequestDigest: " + xml.getChildContent("d:FormDigestValue"));
            return;
            }

        }

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

    CkHttp http = new CkHttp();

    // If SharePoint Windows classic authentication is used, then set the 
    // Login, Password, LoginDomain, and NtlmAuth properties.
    http.put_Login("SHAREPOINT_USERNAME");
    http.put_Password("SHAREPOINT_PASSWORD");
    http.put_LoginDomain("SHAREPOINT_NTLM_DOMAIN");
    http.put_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.
    String savedAccept = http.ck_accept();
    http.put_Accept("application/xml");

    // Note: The last argument ("utf-8") is meaningless here because the body is empty.
    CkHttpResponse resp = http.PostXml("https://SHAREPOINT_HTTPS_DOMAIN/_api/contextinfo","","utf-8");
    if (http.get_LastMethodSuccess() != true) {
        Log.i(TAG, http.lastErrorText());
        return;
        }

    // Restore the default Accept header
    http.put_Accept(savedAccept);

    if (resp.get_StatusCode() != 200) {
        // A response status code not equal to 200 indicates failure.
        Log.i(TAG, "Response status code = " + String.valueOf(resp.get_StatusCode()));
        Log.i(TAG, "Response body:");
        Log.i(TAG, resp.bodyStr());

        return;
        }

    xml.LoadXml(resp.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.
    CkXml xml2 = new CkXml();

    xml2.put_Tag("savedFormDigestValue");
    xml2.NewChild2("d:FormDigestValue",xml.getChildContent("d:FormDigestValue"));

    int timeoutInSec = xml.GetChildIntValue("d:FormDigestTimeoutSeconds");
    Log.i(TAG, "Timeout in seconds = " + String.valueOf(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;
        }

    dtExpire.SetFromCurrentSystemTime();
    dtExpire.AddSeconds(timeoutInSec);
    xml2.NewChild2("d:ExpireDateTime",dtExpire.getAsTimestamp(false));

    // Persist the digest and expire time to a file.
    xml2.SaveXml(formDigestXmlFile);

    Log.i(TAG, "Here is the new form digest value:");
    Log.i(TAG, "X-RequestDigest: " + xml.getChildContent("d:FormDigestValue"));

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}