Develop Reference

How to use OdataNextLink in Microsoft Graph API Beta 5

I was using the Microsoft Graph API 1.0 but have updated to the Beta in order to use CustomSecurityAttributeValue support.
I've managed to port most of the code but I can't see any way to process multiple results pages.
Previously you would just do something like
if (membersPage.NextPageRequest != null)
membersPage = await membersPage.NextPageRequest.GetAsync();
But NextPageRequest no longer exists, the only available information is OdataNextLink which is a string with no obvious way to request the next page or create a raw request using the url.
Code I have so far:
public async Task<IEnumerable<Microsoft.Graph.Beta.Models.User>> GetGraphUsersInGroups(IEnumerable<string> groupIds, string? searchText = null)
{
Dictionary<String, Microsoft.Graph.Beta.Models.User> users = new Dictionary<String, Microsoft.Graph.Beta.Models.User>();
foreach (var groupId in groupIds)
{
try
{
var membersPage = await GraphClient.Groups[groupId].Members
.GetAsync((memberRequest) => {
memberRequest.Headers.Add(new KeyValuePair<string, string>("$count", "true"));
memberRequest.Headers.Add(new KeyValuePair<string, string>("ConsistencyLevel", "eventual"));
memberRequest.QueryParameters.Count = true;
memberRequest.QueryParameters.Orderby = new[] { "displayName" };
if (searchText != null)
memberRequest.QueryParameters.Search = $"\"displayName:{searchText}\"";
});
while (membersPage != null)
{
foreach (var member in membersPage.Value.OfType<Microsoft.Graph.Beta.Models.User>())
{
users[member.Id] = member;
}
if (membersPage.OdataNextLink != null)
{
// How to use membersPage.OdataNextLink???
}
else
break;
}
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
Console.WriteLine(ex.StackTrace);
}
}
return users.Values;
}

You should use the PageIterator, see an example below:
var users = new List<User>();
var userResponse = await serviceClient.Users.GetAsync((builder) => {
// builder.SomeStuff
});
// Added the namespace here, just for some clarity :-)
var pageIterator = Microsoft.Graph.PageIterator<User,UserCollectionResponse>
.CreatePageIterator(serviceClient, userResponse, (user) =>
{
users.Add(user.Id);
return true; });

Trying to run 100 parallel tasks on an iteration doesn't work

Well, I'm trying to run a task 100 times on each run (with paralellism) but I can't manage this to work.
I'm trying to bruteforce an API, for this the API allows me to concatenate as many IDS as possible (without exceeding the timeout)
// consts:
// idsNum = 1000
// maxTasks = 100
// We prepare the ids that we will process (in that case 100,000)
var ids = PrepareIds(i * idsNum * maxTasks, idsNum, maxTasks);
// This was my old approach (didn't work)
//var result = await Task.WhenAll(ids.AsParallel().Select(async x => (await client.GetItems(x)).ToArray()));
// This is my new approach (also this didn't worked...)
var items = new List<item[]>();
ids.AsParallel().Select(x => client.GetItems(x).GetAwaiter().GetResult()).ForAll(item =>
{
//Console.WriteLine("processed!");
items.Add(item.ToArray());
});
var result = items.ToArray();
As you can see I put Console.WriteLine("processed!"); statment, in order to check if anything worked... But I can't manage this to work.
Those are my other methods:
private static IEnumerable<ulong[]> PrepareIds(int startingId, int idsNum = 1000, int maxTasks = 100)
{
for (int i = 0; i < maxTasks; i++)
yield return Range((ulong)startingId, (ulong)(startingId + idsNum)).ToArray();
}
And...
public static async Task<IEnumerable<item>> GetItems(this HttpClient client, ulong[] ids, Action notFoundCallback = null)
{
var keys = PrepareDataInKeys(type, ids); // This prepares the data to be sent to the API server
var content = new FormUrlEncodedContent(keys);
content.Headers.ContentType =
new MediaTypeHeaderValue("application/x-www-form-urlencoded") { CharSet = "UTF-8" };
client.DefaultRequestHeaders.ExpectContinue = false;
// We create a post request
var response = await client.PostAsync(new Uri(FILE_URL), content);
string contents = null;
JObject jObject;
try
{
contents = await response.Content.ReadAsStringAsync();
jObject = JsonConvert.DeserializeObject<JObject>(contents);
}
catch (Exception ex)
{
Console.WriteLine(ex);
Console.WriteLine(contents);
return null;
}
// Then we read the items from the parsed JObject
JArray items;
try
{
items = jObject
.GetValue("...")
.ToObject<JObject>()
.GetValue("...").ToObject<JArray>();
}
catch (Exception ex)
{
Console.WriteLine(ex);
return null;
}
int notFoundItems = 0;
int nonxxxItems = 0;
int xxxItems = 0;
var all = items.BuildEnumerable(notFoundCallback, item =>
{
if (item.Result != 1)
++notFoundItems;
else if (item.id != 5)
++nonxxxItems;
else
++xxxItems;
});
CrawledItems += ids.Length;
NotFoundItems += notFoundItems;
NonXXXItems += nonxxxItems;
XXXItems += xxxItems;
return all;
}
private static IEnumerable<item> BuildEnumerable(this JArray items, Action notFoundCallback, Action<item> callback = null)
{
foreach (var item in items)
{
item _item;
try
{
_item = new item(item.ToObject<JObject>());
callback?.Invoke(_item);
}
catch (Exception ex)
{
if (notFoundCallback == null)
Console.WriteLine(ex, Color.Red);
else
notFoundCallback();
continue;
}
yield return _item;
}
}
So as you can see I create 100 parallel post requests using an HttpClient. But I can't manage it to work.
So the thing that I want to achieve is to retrieve as many items as possible because I need to crawl +2,000,000,000 items.
But any breakpoint is triggered, neither any caption is updated on Console (I'm using Konsole project in order to print values at a fixed position on console), so any advice can be given there?

This OperationContextScope is being disposed out of order

I am calling WCF service in ASP.NET Core and everything is working fine, but whenever end of using gets executed, I get an error:
This OperationContextScope is being disposed out of order
I believe I am using wrong pattern to call WCF service using async/await but I am not sure what I am doing wrong.
Below is the code I am using to call a service.
[HttpPost]
public async Task<IActionResult> Runcase(IFormCollection formCollection)
{
if (ModelState.IsValid)
{
var runnumber = formCollection["Run number"];
await CallServiceasync();
return RedirectToAction("", "");
}
else
{
return View(formCollection);
}
}
public async Task CallServiceasync()
{
var product = p1.Value;
var a = product.first;
foreach (int Age in a.age)
{
foreach (int Gender in a.sex)
{
foreach (int Healthclass in a.uclass)
{
RequestData requestData = new RequestData()
{
ProductID = 534,
STATE = "CO",
AGE1 = Age,
SEX1 = Gender,
UND_CLASS1 = Healthclass,
};
RecieveResponseasync(requestData);
}
}
}
}
public async Task RecieveResponseasync(InputValues inputValues)
{
string reqedata = "";
string apikey = "001010iZno7001010L";
QuoteEngineService.MarketingSoftwareClient Service = new QuoteEngineService.MarketingSoftwareClient();
await Service.OpenAsync();
try
{
using (OperationContextScope scope = new OperationContextScope(Service.InnerChannel))
{
HttpRequestMessageProperty httpRequestMessage = new HttpRequestMessageProperty();
httpRequestMessage.Headers.Add("apikey", apikey);
OperationContext.Current.OutgoingMessageProperties[HttpRequestMessageProperty.Name] = httpRequestMessage;
reqedata = inputValues.XmlSerializetoString();
var result = await Service.ProcessRequestAsync(reqedata, "4fa2-ae27");
var outputvalues = new OutputvaluesViewModel();
outputvalues = result.DeserializeToObject();
List<OutputValue> outputs = new List<OutputValue>();
if (outputvalues.InitialPremium != null)
outputs.Add(new OutputValue { Name = "InitialPremium", Result = outputvalues.InitialPremium});
if (outputvalues.TargetPremium != null)
outputs.Add(new OutputValue { Name = "TargetPremium", Result = outputvalues.TargetPremium });
foreach (var output in outputs)
{
await _context.outputValues.AddAsync(output);
await _context.SaveChangesAsync();
}
await Task.Delay(500);
}
}// **At this point I am getting error**
catch (Exception ex)
{
throw;
}
finally
{
if (Service.State == System.ServiceModel.CommunicationState.Opened)
{
await Service.CloseAsync();
}
}
}

From the docs:
Warning
Do not use the asynchronous "await" pattern within a OperationContextScope block. When the continuation occurs, it may run on a different thread and OperationContextScope is thread specific. If you need to call "await" for an async call, use it outside of the OperationContextScope block.

Multithreaded c# console app to scrape data from sites

I have written an app that goes through our own properties and scraps the data. To make sure I don't run through the same URLs, I am using a MySQL database to store the URL, flag it once its processed. All this was being done in a single thread and it's fine if I had only few thousand entries. But I have few hundred thousand entries that I need to parse so I need to make changes in the code (I am newbie in multithreading in general). I found an example and was trying to copy the style but doesn't seem to work. Anyone know what the issue is with the following code?
EDIT: Sorry didn't mean to make people guess the issue but was stupid of me to include the exception. Here is the exception
"System.InValidCastException: 'Specified cast is not valid.'"
When I start the process it collects the URLs from the database and then never hits DoWork method
//This will get the entries from the database
List<Mappings> items = bot.GetUrlsToProcess(100);
if (items != null)
{
var tokenSource = new CancellationTokenSource();
var token = tokenSource.Token;
Worker.Done = new Worker.DoneDelegate(WorkerDone);
foreach (var item in items)
{
urls.Add(item.Url);
WaitingTasks.Enqueue(new Task(id => new Worker().DoWork((int)id, item.Url, token), item.Url, token));
}
LaunchTasks();
}
static async void LaunchTasks()
{
// keep checking until we're done
while ((WaitingTasks.Count > 0) || (RunningTasks.Count > 0))
{
// launch tasks when there's room
while ((WaitingTasks.Count > 0) && (RunningTasks.Count < MaxRunningTasks))
{
Task task = WaitingTasks.Dequeue();
lock (RunningTasks) RunningTasks.Add((int)task.AsyncState, task);
task.Start();
}
UpdateConsole();
await Task.Delay(300); // wait before checking again
}
UpdateConsole(); // all done
}
static void UpdateConsole()
{
Console.Write(string.Format("\rwaiting: {0,3:##0} running: {1,3:##0} ", WaitingTasks.Count, RunningTasks.Count));
}
static void WorkerDone(int id)
{
lock (RunningTasks) RunningTasks.Remove(id);
}
public class Worker
{
public delegate void DoneDelegate(int taskId);
public static DoneDelegate Done { private get; set; }
public async void DoWork(object id, string url, CancellationToken token)
{
if (token.IsCancellationRequested) return;
Content obj;
try
{
int tries = 0;
bool IsUrlProcessed = true;
DateTime dtStart = DateTime.Now;
string articleDate = string.Empty;
try
{
ScrapeWeb bot = new ScrapeWeb();
SearchApi searchApi = new SearchApi();
SearchHits searchHits = searchApi.Url(url, 5, 0);
if (searchHits.Hits.Count() == 0)
{
obj = await bot.ReturnArticleObject(url);
if (obj.Code != HttpStatusCode.OK)
{
Console.WriteLine(string.Format("\r Status is {0}", obj.Code));
tries = itemfound.UrlMaxTries + 1;
IsUrlProcessed = false;
itemfound.HttpCode = obj.Code;
}
else
{
string title = obj.Title;
string content = obj.Contents;
string description = obj.Description;
Articles article = new Articles();
article.Site = url.GetSite();
article.Content = content;
article.Title = title;
article.Url = url.ToLower();
article.Description = description;
string strThumbNail = HtmlHelper.GetImageUrl(url, obj.RawResponse);
article.Author = HtmlHelper.GetAuthor(url, obj.RawResponse);
if (!string.IsNullOrEmpty(strThumbNail))
{
//This condition needs to be added to remove ?n=<number> from EP thumbnails
if (strThumbNail.Contains("?"))
{
article.ImageUrl = strThumbNail.Substring(0, strThumbNail.IndexOf("?")).Replace("http:", "https:");
}
else
article.ImageUrl = strThumbNail.Replace("http:", "https:");
}
else
{
article.ImageUrl = string.IsNullOrEmpty(strThumbNail) ? article.Url.GetDefaultImageUrls() : strThumbNail.Replace("http:", "https:");
}
articleDate = HtmlHelper.GetPublishDate(url, obj.RawResponse);
if (string.IsNullOrEmpty(articleDate))
article.Pubdate = DateTime.Now;
else
article.Pubdate = DateTime.Parse(articleDate);
var client = new Index(searchApi);
var result = client.Upsert(article);
itemfound.HttpCode = obj.Code;
if (result)
{
itemfound.DateCreated = DateTime.Parse(articleDate);
itemfound.DateModified = DateTime.Parse(articleDate);
UpdateItem(itemfound);
}
else
{
tries = itemfound.UrlMaxTries + 1;
IsUrlProcessed = false;
itemfound.DateCreated = DateTime.Parse(articleDate);
itemfound.DateModified = DateTime.Parse(articleDate) == null ? DateTime.Now : DateTime.Parse(articleDate);
UpdateItem(itemfound, tries, IsUrlProcessed);
}
}
}
else
{
tries = itemfound.UrlMaxTries + 1;
IsUrlProcessed = true;
itemfound.HttpCode = HttpStatusCode.OK;
itemfound.DateCreated = DateTime.Parse(articleDate);
itemfound.DateModified = DateTime.Parse(articleDate) == null ? DateTime.Now : DateTime.Parse(articleDate);
}
}
catch (Exception e)
{
tries = itemfound.UrlMaxTries + 1;
IsUrlProcessed = false;
itemfound.DateCreated = DateTime.Parse(articleDate);
itemfound.DateModified = DateTime.Parse(articleDate) == null ? DateTime.Now : DateTime.Parse(articleDate);
}
finally
{
DateTime dtEnd = DateTime.Now;
Console.WriteLine(string.Format("\r Total time taken to process items is {0}", (dtEnd - dtStart).TotalSeconds));
}
}
catch (Exception e)
{
Console.WriteLine(e);
}
Done((int)id);
}
}
All this code is based from Best multi-thread approach for multiple web requests this link. Can someone tell me how to get this approach running?

I think the problem is in the way you're creating your tasks:
new Task(id => new Worker().DoWork((int)id, item.Url, token), item.Url, token)
This Task constructor overload expected Action<object> delegate. That means id will be typed as object and you need to cast it back to something useful first.
Parameters
action
Type: System.Action<Object>
The delegate that represents the code to execute in the task.
state
Type: System.Object
An object representing data to be used by the action.
cancellationToken
Type: System.Threading.CancellationToken
-The CancellationToken that that the new task will observe.
You decided to cast it to int by calling (int)id, but you're passing item.Url as the object itself. I can't tell you 100% what the type of Url is but I don't expect Url-named property to be of type int.

Based on what #MarcinJuraszek said I just went back to my code and added an int as I couldn't find another way to resolve it. Here is the change I made
int i=0
foreach (var item in items)
{
urls.Add(item.Url);
WaitingTasks.Enqueue(new Task(id => new Worker().DoWork((string)id, item.Url, token), item.Url, token));
i++;
}

WaitAll with Task not working

I Created several Task in the way below. But it seems WaitAll is not working. It is sending response without wait. Anything goes wrong here?
private void GetItemsPrice(IEnumerable<Item> items, int customerNumber)
{
try
{
var tasks = new List<Task>();
for (var i = 0; i < items.Count(); i += 50)
{
var newTask = DoGetItemsPrice(items.Skip(i).Take(50), customerNumber);
tasks.Add(newTask);
}
Task.WaitAll(tasks.ToArray());
}
catch (Exception ex)
{
ErrorLog.WriteLog(GetType().Name, "GetItemsPrice", string.Format("customerNumber={0}", customerNumber), ex.Message);
}
}
private static Task DoGetItemsPrice(IEnumerable<Item> items, int customerNumber)
{
return Task.Factory.StartNew(() =>
{
var sxApiObj = new SxApiService();
var request = new OEPricingMultipleRequest();
request.customerNumber = customerNumber;
request.arrayProduct =
items.Select(
itemCode =>
new OEPricingMultipleinputProduct
{
productCode = itemCode.ItmNum,
quantity = itemCode.Quantity,
warehouse = ConfigurationVariables.DefaultWareHouse
}).ToArray();
var response = sxApiObj.OEPricingMultiple(ConfigurationVariables.SfAppServer,
ConfigurationVariables.SfUserId,
ConfigurationVariables.SfPassword,
request);
if (response.arrayPrice != null)
{
foreach (var priceData in response.arrayPrice)
{
var productCode = priceData.productCode;
var item = items.FirstOrDefault(itm => itm.ItmNum == productCode);
if (item == null) continue;
item.ItmListPrice1 = priceData.price.ToString("c", ConfigurationVariables.UsCulture);
item.ItmListPrice2 = priceData.discountAmount.ToString("c", ConfigurationVariables.UsCulture);
item.ItmListPrice3 = priceData.extendedAmount.ToString("c", ConfigurationVariables.UsCulture);
item.Quantity = priceData.netAvailable;
}
}
});
}

There is nothing wrong with my question. WaitAll works fine and the code also correct.