Here an example of how retrieve SharePoint list data using Rest API and pagination.
It is a particularly useful when the list has a number of record greater than the SharePoint threshold limit (5.000 items): be careful when you use $filter statement because if the result of the filtered record is greater than the threshold, you get an error even if you are using the pagination.
This code can be used on every SharePoint list, thanks to the dynamic type of the de-serialized class, using the internal field name in order to access to the property value.
Between the lines the comments...
usingMicrosoft.SharePoint.Client;
usingNewtonsoft.Json;
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Net.Http;
usingSystem.Security;
usingSystem.Threading.Tasks;
namespacezPagingRestExample
{
class Program
{
//Constants
private const intPAGESIZE = 5000;
private const stringUSERNAME = "[email protected]";
private const string PWD = "wlamu$$a.3";
private const stringSPSITE = "https://zsis.sharepoint.com/sites/TestFlow";
//skiptoken=Paged=TRUE means that you need paging
//$top means the number of record for each page
private const stringRESTURL = "{0}/_api/web/lists/getbytitle('BigList')/items?&$skiptoken=Paged=TRUE&$top={1}&$select=Title, MyDate, Id";
static voidMain(string[] args)
{
HttpClientHandlerhandler = null;
try
{
//Creating the REST url setting the right filter parameter
//and the size of each page
stringrestUrl = string.Format(RESTURL, SPSITE, PAGESIZE);
//Getting authenticated handler using cookies
//I ask to autenticate to SP only once
//and use the same handler again
handler = getClientHandler(SPSITE, USERNAME, PWD);
//Getting data
TaskSPData.Rootobject> result = getSPData(restUrl, handler);
result.Wait();
//Display retrieved data
Console.WriteLine(result.Result.Items.Count.ToString());
Console.ReadLine();
foreach (var item in result.Result.Items)
{
//You can use the internal name of the field!!!
//each item of the Items collection is a dynamic value
//then you can use this code for any SharePoint list
Console.WriteLine((string)item.Title);
Console.WriteLine((string)item.MyDate);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
Console.ReadLine();
}
finally
{
//Disposing Handler
if(handler == null)
{
handler.Dispose();
handler = null;
}
}
}
//Private funcionts
///
/// Returns all data specified in the restUrl parameter
///
/// restUrl">
/// handler">
///
private static async TaskSPData.Rootobject> getSPData(string restUrl, HttpClientHandlerhandler)
{
using (varclient = new HttpClient(handler))
{
//Adding Header
client.DefaultRequestHeaders.Accept.Clear();
//Use nometadata in order to reduce the message size
//Take a look at this...
//http://zsvipullo.blogspot.it/2016/10/sharepoint-rest-api-drastically-reduce.html
client.DefaultRequestHeaders.Add("Accept", "application/json;odata=nometadata");
//Calling SP REST Service
HttpResponseMessageresponse = await client.GetAsync(restUrl).ConfigureAwait(false);
response.EnsureSuccessStatusCode();
//Getting string JSON Content and parse it into a dynamic object
stringjsonData = await response.Content.ReadAsStringAsync();
//dynamic d = JObject.Parse(jsonData);
//Deserialising json string into SPData.Rootobject object
//Thanks to Newtonsoft.Json work
SPData.Rootobject res = JsonConvert.DeserializeObjectSPData.Rootobject>(jsonData);
//If odatanextLink is null, I reach the last page
//otherwise i recursively call the getSPData function passing the new page rest url
if (!string.IsNullOrWhiteSpace(res.OdatanextLink))
{
varnestedRes = getSPData(res.OdatanextLink, handler);
res.Items.AddRange(nestedRes.Result.Items);
}
return res;
}
}
///
/// Returns an authenticated HttpClientHandler
///
/// spSiteUrl">
/// username">
/// pwd">
///
private static HttpClientHandlergetClientHandler(string spSiteUrl, stringusername, string pwd)
{
//Creating Credentials
var passWord = new SecureString();
foreach (var c in pwd) passWord.AppendChar(c);
var credential = new SharePointOnlineCredentials(username, passWord);
HttpClientHandlerhandler = new HttpClientHandler() { Credentials = credential };
//Getting authentication cookies
Uri uri = new Uri(spSiteUrl);
handler.CookieContainer.SetCookies(uri, credential.GetAuthenticationCookie(uri));
returnhandler;
}
}
//Classes
public class SPData
{
public class Rootobject
{
[JsonProperty(PropertyName = "odata.nextLink")]
public stringOdatanextLink { get; set; }
[JsonProperty(PropertyName = "value")]
public Listdynamic> Items { get; set; }
}
}
}
