I have an API POST endpoint creating a resource, that resource may have multiple relationships. To make sure the resource is created with valid relationships first I need to check if the given IDs exist. There are multiple such relations, and I don't want to await each sequentially. Here's my code:
[HttpPost]
public async Task<ActionResult<Person>> PostPerson(Person person)
{
ValueTask<Person> master, apprentice;
ValueTask<Planet> planet;
ValueTask<Models.LifeFormType> lifeFormType;
if (person.MasterId.HasValue)
{
master = _context.People.FindAsync(person.MasterId);
}
if (person.ApprenticeId.HasValue)
{
apprentice = _context.People.FindAsync(person.ApprenticeId);
}
if (person.FromPlanetId.HasValue)
{
planet = _context.Planets.FindAsync(person.FromPlanetId);
}
if (person.LFTypeId.HasValue)
{
lifeFormType = _context.LifeFormTypes.FindAsync(person.LFTypeId);
}
List<ValueTask> tasks = new List<ValueTask> {master, apprentice, planet, lifeFormType};
// if the above worked I'd process the tasks as they completed and throw errors
// if the given id was not found and such
_context.Attach(person);
// _context.People.Add(person);
await _context.SaveChangesAsync();
return CreatedAtAction("GetPerson", new { id = person.Id }, person);
}
As shown here I want to await the list of [master,apprentice,planet,lifeFormType] as they complete, but I get an error during the creation of the list that Local variable 'master' might not be initialized before accessing. So I tried in each check if the resource has that value to create an else block and somehow add a ValueTask.CompletedTask like so:
if (person.MasterId.HasValue)
{
master = _context.People.FindAsync(person.MasterId);
}
else
{
master = ValueTask.CompletedTask;
}
but then I get an error saying that Cannot convert source type 'System.Threading.Tasks.ValueTask' to target type 'System.Threading.Tasks.ValueTask<Models.Person>'.
How to do this? I guess I'll just await each and every request for now.
You can avoid this by initializing master at the declaration site.
The easiest way is using the default keyword.
ValueTask<Person> master = default;
Related
I had a similar issue with this question, when updating a record using EF6.
I really thought I had cracked the whole updating thing, but now have to almost identical functions updating in what I think was an identical way. One works, the other doesn't. I have fixed the one that doesn't work by using Jamie's comment in the above question, but I'd like to understand if the function that works, really shouldn't and so is on borrowed time and I should make more like the 'fixed' one. Or, why the 'fixed' one didn't work in the first place. I even moved them into the same controller so that the database (DB) context was guaranteed the same. Have I missed something and they are not identical (functionally) at all?
It might also help some others out there that struggle with this as I did.
The function that works (cut down) is:
[HttpPost]
[Route("UpdateAddBusinessService")]
public async Task<IHttpActionResult> UpdateAddBusinessService(BusinessServiceDTO servicetoupdateoradd)
{
... pre check stuff...
try
{
if (servicetoupdateoradd.Id != null) // This is an existing service to be updated - if Is Null then create new
{
BusinessService businessService = await db.BusinessServices.FindAsync(servicetoupdateoradd.Id);
if (businessService != null)
{
Mapper.Map(servicetoupdateoradd, businessService);
db.Entry(businessService).State = EntityState.Modified;
await db.SaveChangesAsync();
return Ok("Service Updated");
}
else
The function that doesn't work is:
[HttpPost]
[Route("UpdateImage")]
public async Task<IHttpActionResult> UpdateImage(ImageDTO imageDTO)
{
... pre check stuff ...
try
{
// First find the image
// Image imagetoupdate = await db.Images.FindAsync(imageDTO.Id); <<-This FAILS.
Image imagetoupdate = db.Images.AsNoTracking().Single(x => x.Id == imageDTO.Id); <<- This WORKS
if (imagetoupdate != null)
{
imagetoupdate = Mapper.Map<ImageDTO, Image>(imageDTO); // Move the stuff over..
db.Entry(imagetoupdate).State = EntityState.Modified;
await db.SaveChangesAsync();
return Ok();
}
I wondered (as you will no doubt), if my Mapper function was doing anything, but I suspect not (without digging too deep, but I guess it could be), my Mapper.Config functions for the two DTO's are very similar:
cfg.CreateMap<Image, ImageDTO>();
cfg.CreateMap<ImageDTO, Image>();
and:
cfg.CreateMap<BusinessService, BusinessServiceDTO>();
cfg.CreateMap<BusinessServiceDTO, BusinessService>();
I would really just like to understand the 'correct' way of doing this so it doesn't bite me again. Thanks in advance.
EDIT: I was asked (quite reasonably) if the 'pre-check stuff' does anything to fetch the data, it doesn't, but there is a subtle difference, that I might have missed...
This is from the BusinessService function that works:
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
string userid = User.Identity.GetUserId(); //Check user is valid
if (servicetoupdateoradd.UserId != userid)
{
var message = "User Id Not found - Contact support";
HttpResponseMessage err = new HttpResponseMessage() { StatusCode = HttpStatusCode.ExpectationFailed, ReasonPhrase = message };
return ResponseMessage(err);
}
This is from the UpdateImage function that didn't work:
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
string userid = User.Identity.GetUserId();
SGGUser user = db.Users.Find(userid); // Use this find and not UserManager becuase its a different context and buggers up the file save
if (user == null)
{
var message = "User Id Not found - Contact support";
HttpResponseMessage err = new HttpResponseMessage() { StatusCode = HttpStatusCode.ExpectationFailed, ReasonPhrase = message };
return ResponseMessage(err);
}
I see that in this one, though I don't fetch the relevant data, I do use the 'db' context.. could that be it?? The Image object does contain a reference to the user, so maybe that does some magic in the background code?
Appologies, I just didn't want to clutter up the question too much...
This line:
Mapper.Map(servicetoupdateoradd, businessService);
and this line:
imagetoupdate = Mapper.Map<ImageDTO, Image>(imageDTO); // Move the stuff over..
look similar, but do two different things.
The first line will tell Automapper to copy values from the first object over to the second object reference using the mapping rules.
The second line will tell Automapper to make a completely new reference to the entity with the mapped over values from the provided object and return it.
So in the first case, the entity reference is preserved to the one the DbContext knows about. The reference was loaded from a DbContext and should be tracking changes so you shouldn't even need to set it's entity state. In the second case, Automapper is creating an entirely new reference and assigning it over top the original reference. EF is treating that as a completely new instance and trying to attach it, resulting in it complaining because the context had already loaded that entity, you just overwrote the reference.
It should work if you change the second instance to:
Mapper.Map(imageDTO, imagetoupdate);
I am writing a chat bot that can ask a user for name and a requirement to search job with.
Name and Requirement will be stored in UserData and PrivateConversationData.
I am trying to send the requirement as an index, 1-5, to a method dialog and to specify a requirement like salary amount and then call an appropriate api. But the bot keep giving an error when passing the parameter. How can I fix the error? Is it the way my method receives it or I use the wrong way to call it?
I'm trying to combine the requirement and job stuff into one single to prevent [Community Edit: To prevent what?]
private async Task MessageReceivedAsync(IDialogContext context, IAwaitable<object> result)
{
if (string.IsNullOrEmpty(name))//ask for the name
{
//code for get name
}
else
{
context.PrivateConversationData.TryGetValue<int>("Index", out int index);
if (!Enumerable.Range(1, 5).Contains(index))
{
var getRequirement =
FormDialog.FromForm(Requirement.BuildForm,
FormOptions.PromptInStart);
context.Call(getRequirement, AfterGetRequirementAsync);//able to get requirement index as int 1~5. next going to ask what specific value
}
else
{
await context.PostAsync($"{name}:{index}: {activity.Text}");//testing: it is able to print the name and the index user choose
context.Wait(MessageReceivedAsync);
}
}
I am using context.Call(getRequirement, AfterGetRequirementAsync) to try to get both requirement and then ask for the specific value in AfterGetRequirementAsync.
private async Task AfterGetRequirementAsync(IDialogContext context, IAwaitable<Requirement> result)
{
//Requirement requirementindex = null;
var requirementindex = await result;
context.PrivateConversationData.SetValue<int>("Index", requirementindex.Index);
await context.PostAsync($"Result：{JsonConvert.SerializeObject(requirementindex)}");//for testing index after user's input about index
var jobs = await GetJobDialog.LoadJob(requirementindex.Index);//Im trying to pass the .Index
//await context.PostAsync($"Job Search Result : {Environment.NewLine}{JsonConvert.SerializeObject(jobs)}");//trying to print the list of result to user
context.Wait(MessageReceivedAsync);
}
In AfterGetRequirementAsync, it is able to get the requirementindex and I can store it in PrivateConversationData in MessageReceivedAsync as Index. But when I try to pass the requirementindex.Index to GetJobDialog.JobModel.LoadJob it give me error of [Community Edit: What's the error?]
public class GetJobDialog
{
public Task StartAsync(IDialogContext context)
{
context.Wait(LoadJob(context.UserData));
return Task.CompletedTask;
}
public static async Task<List<JobModel>> LoadJob(IDialog context, IAwaitable<JobResultModel> result, int index)//depends on the job searching index, using different method to search.
{//it should return list of jobs to user.
string url = "";
if (index == 1)//posting type
{ //code like index == 4 }
else if (index == 2)//level
{ //code like index == 4 }
else if (index == 3)//full time or part time
{ //code like index == 4 }
else if (index == 4)//salary from
{ //ask for internal or external and change the end= to match value
url = $"https://data.cityofnewyork.us/resource/kpav-sd4t.json?salary_range_from=40000";
}//the only thing different is after .json? the index = specific value
else if (index == 5)//salary to
{ //code like index == 4 }
else//if not getting any valid option, throw error message and ask for index again
{
}
using (HttpResponseMessage response = await ApiHelper.ApiHelper.ApiClient.GetAsync(url))
{
if (response.IsSuccessStatusCode)
{
JobResultModel job = await response.Content.ReadAsAsync<JobResultModel>();
return job.Results;
}
else
{
throw new Exception(response.ReasonPhrase);
}
}
}
}
I am also trying to get the user to input the specific amount in the GetJobDialog. That way, the user doesn't have to enter anything to trigger the chat bot again.
I'm just posting the API caller incase I have some mistake because I learn all these by myself and do not have a clear understanding of how C# and api work.
public static class ApiHelper
{
public static HttpClient ApiClient { get; set; }
public static void InitializeClient()
{
ApiClient = new HttpClient();
ApiClient.DefaultRequestHeaders.Accept.Clear();
ApiClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
}
}
I expect the chat bot be able to pass the index to LoadJob and ask for specific value before or after the call of LoadJob. Then response a list of job with different field to the user.
I see a few issues with your code that might be causing this. If you can link me to all of your code, I might be able to help debug. In the meantime, here's some things might be causing the problem:
You're using BotBuilder V3 Code. If you're writing a new bot, you should really be using Botframework V4. Here's a State Management Sample Bot that can help you get started. You really should switch to V4, especially if this is a newer bot. If you run into issues in the future, you'll receive better support.
It looks like you're saving Index to PrivateConversationData, but when you pass it LoadJob(), you're using UserData instead.
I'm not sure that you can pass information when using context.Wait(). None of the V3 Samples do that. I don't use V3 much, so I can't tell for sure. What you should instead do, is use something like context.PrivateConversationData.TryGetValue<int>("Index", out int index); to load the index instead of passing it.
It also looks like you didn't post the error message. If you can post that and all of your code, I can help debug further (if the above doesn't work).
I'm getting an int Id from server which in HTTP request in flutter, it is OK and I want to save this value in an variable , but when i call the returned value i get this error Instance of 'Future' , any suggestion ??
Here is the code
child: RaisedButton(onPressed:() {
CurrentPrjId= SaveProject();
print("CurrentPrjId Is saved CurrentPrjId :::::::: " );
print(CurrentPrjId);
Navigator.of(context).pushReplacementNamed('/AllUSerStories');
}
//Save Project
Future SaveProject() async {
//SaveProjectResult has the id of the current created project which i need that for its user stories
var SaveProjectResult = await GetPostProjects().createProject(_ProjectnameController.text, _CustomernameController.text, _dropNewItem, _dropNewItem2, _StartDateController.text, _EndDateController.text,);
print(":::::::::::::::::::::::::::::::The Project Is Created And Here Its ID In SaveProject:::::::::");
print(SaveProjectResult);
return SaveProjectResult;
}
Without having your code, it's hard to guess, whats going on.. But you may try to wait for the completion of the future.. so do this:
methOdThatLoadsId().then((id) => print("Id that was loaded: $id"));
or
var id = await methodThatLoadsId();
Good luck :)
sorry for the late reply.
You've added the await at the wrong place unfortunately.
Try something like this:
child: RaisedButton(onPressed:() async {
CurrentPrjId= await SaveProject();
print("CurrentPrjId Is saved CurrentPrjId :::::::: " );
print(CurrentPrjId);
Navigator.of(context).pushReplacementNamed('/AllUSerStories');
}
//Save Project
Future SaveProject() async {
//SaveProjectResult has the id of the current created project which i need that for its user stories
var SaveProjectResult = await GetPostProjects().createProject(_ProjectnameController.text, _CustomernameController.text, _dropNewItem, _dropNewItem2, _StartDateController.text, _EndDateController.text,);
print(":::::::::::::::::::::::::::::::The Project Is Created And Here Its ID In SaveProject:::::::::");
print(SaveProjectResult);
return SaveProjectResult;
Or shorter:
child: RaisedButton(onPressed:() async {
CurrentPrjId= await GetPostProjects().createProject(_ProjectnameController.text, _CustomernameController.text, _dropNewItem, _dropNewItem2, _StartDateController.text, _EndDateController.text,);
print("CurrentPrjId Is saved CurrentPrjId :::::::: " );
print(CurrentPrjId);
Navigator.of(context).pushReplacementNamed('/AllUSerStories');
}
You have to use a FutureBuilder widget to get Future value from an async call.
CurrentPrjId=FutureBuilder<String>(
future: SaveProject(),
builder: (context, snapshot) {
if (snapshot.hasData) return Text(snapshot.data);
else if (snapshot.hasError) return Text(snapshot.error);
return return Text("Await for data");
},
);
Using NopCommerce 3.8, Visual Studio 2015 proff.
I have created a plugin that is responsible for making restful calls to my Web API that exposes a different DB to that of Nop.
The process is run via a nop Task, it successfully pulls the data back and i can step through and manipulate as i see fit, no issues so far.
Issue comes when i try to update a record on the product table, i perform the update... but nothing happens no change, no error.
I believe this is due to the Context having no idea about my newly instantiated product object, however I'm drawing a blank on what i need to do in relation to my particular example.
Similar questions usually reference a "model" object that is part of the parameter of the method call, "model" has the method ToEntity which seems to be the answer in similar question in stack.
However my example doesn't have the ToEntity class/method possibly because my parameter is actually a list of products. To Clarify here my code.
Method in RestClient.cs
public async Task<List<T>> GetAsync()
{
try
{
var httpClient = new HttpClient();
var json = await httpClient.GetStringAsync(ApiControllerURL);
var taskModels = JsonConvert.DeserializeObject<List<T>>(json);
return taskModels;
}
catch (Exception e)
{
return null;
}
}
Method in my Service Class
public async Task<List<MWProduct>> GetProductsAsync()
{
RestClient<MWProduct> restClient = new RestClient<MWProduct>(ApiConst.Products);
var productsList = await restClient.GetAsync();
InsertSyncProd(productsList.Select(x => x).ToList());
return productsList;
}
private void InsertSyncProd(List<MWProduct> inserted)
{
var model = inserted.Select(x =>
{
switch (x.AD_Action)
{
case "I":
//_productService.InsertProduct(row);
break;
case "U":
UpdateSyncProd(inserted);
.....
Then the method to bind and update
private void UpdateSyncProd(List<MWProduct> inserted)
{
var me = inserted.Select(x =>
{
var productEnt = _productRepos.Table.FirstOrDefault(ent => ent.Sku == x.Sku.ToString());
if(productEnt != null)
{
productEnt.Sku = x.Sku.ToString();
productEnt.ShortDescription = x.ShortDescription;
productEnt.FullDescription = x.FullDescription;
productEnt.Name = x.Name;
productEnt.Height = x.Pd_height != null ? Convert.ToDecimal(x.Pd_height) : 0;
productEnt.Width = x.Pd_width != null ? Convert.ToDecimal(x.Pd_width) : 0;
productEnt.Length = x.Pd_depth != null ? Convert.ToDecimal(x.Pd_depth) : 0;
productEnt.UpdatedOnUtc = DateTime.UtcNow;
}
//TODO: set to entity so context nows and can update
_productService.UpdateProduct(productEnt);
return productEnt;
});
}
So as you can see, I get the data and pass data through to certain method based on a result. From that list in the method I iterate over, and pull the the entity from the table, then update via the product service using that manipulated entity.
So what am I missing here, I'm sure its 1 step, and i think it may be either be because 1) The context still has no idea about the entity in question, or 2) Its Incorrect calls.
Summary
Update is not updating, possibly due to context having no knowledge OR my methodology is wrong. (probably both).
UPDATE:
I added some logger.inertlog all around my service, it runs through fine, all to the point of the call of update. But again I check the product and nothing has changed in the admin section.
plugin
I have provided the full source as i think maybe this has something to do with the rest of the code setup possibly?
UPDATE:
Added the following for testin on my execute method.
var myprod = _productRepos.GetById(4852);
myprod.ShortDescription = "db test";
productRepos.Update(myprod);
This successfully updates the product description. I moved my methods from my service into the task class but still no luck. The more i look at it the more im thinking that my async is killing off the db context somehow.
Turned of async and bound the getbyid to a new product, also removed the lambda for the switch and changed it to a foreach loop. Seems to finally update the results.
Cannot confirm if async is the culprit, currently the web api seems to be returning the same result even though the data has changed (some wierd caching by deafult in .net core? ) so im creating a new question for that.
UPDATE: It appears that the issue stems from poor debugging of async. Each instance I am trying to iterate over an await call, simply put im trying to iterate over a collection that technically may or may not be completed yet. And probably due to poor debugging, I was not aware.
So answer await your collection Then iterate after.
I have come across this thread already, but I might need something else for my situation.
I have an action that returns a ViewResult, which is called by the client's $.post()
JavaScript:
var link = 'GetFoo?fooBar=' + fooBar;
var jqxhr = $.post(link, function (response) {
$('#myDiv').replaceWith(response);
});
Controller:
public ViewResult GetFoo(String fooBar)
{
if (Request.IsAjaxRequest())
{
// perform a ridiculously long task (~12 minutes)
// algorithm: 1) download files from the Azure blob storage
// 2) update each file
// 3) reupload to blob storage
// 4) return a list of URIs to be displayed to the UI
return View("MyFooView", data);
}
throw new InvalidOperationException();
}
As the comment implies, there is long task running inside the Controller. (This is a document generation module that uploads PDFs to the Azure blob storage and returns a link to it to the View.)
This is working fine in my dev machine but when it goes live in a (secure) Azure production environment, it times out. I have put in lots of logging entries everywhere and as it turns out, it is able to upload the documents and return to the controller (i.e. it reaches the controller return statement above). However, when it is time to return the model data to the View, the client script doesn't called back (i.e. the div content doesn't get replaced with the results).
Is there a way to somehow prolong the timeout of the call? It is difficult to reproduce in my (unsecure) local environment so a definitive fix will help.
If I use the attribute [AsyncTimeout(3600)] on my GetFoo() method, then this action never gets called from the UI.
Any suggestions will be appreciated.
The problem is that the Azure load balancer has it's own timeout which is set to one minute. Any request that takes longer than a minute gets terminated. There is no way to change this.
The way around this in the Azure environment is to have one ajax call start the process and return some sort of process ID then have the client poll another ajax call to passing in this process ID to see if it's complete. It might looks something like this uncompiled and untested code. In javascript:
var link = 'BeginFooProcessing?fooBar=' + fooBar;
var jqxhr = $.post(link, function (response) {
var finishedlink = 'CheckFooFinished?fooId=' + response;
// Check to see if we're finished in 1 second
setTimeout("CheckIfFinishedYet('" + finishedlink + "')", 1000);
});
function CheckIfFinishedYet(finishedlink) {
var response = $.post(finishedlink, function (response) {
if (response == null) {
// if we didn't get a result, then check in another second
setTimeout("CheckIfFinishedYet('" + finishedlink + "')", 1000);
}
else {
// Yay, we've got a result so we'll just write it out
$('#myDiv').replaceWith(response);
}
});
}
And in your controller:
public ViewResult BeginFooProcessing(String fooBar)
{
if (Request.IsAjaxRequest())
{
Guid fooId = Guid.NewGuid();
var result = new FooResult
{
FooId = fooId,
HasFinishedProcessing = false,
Uris = new List<string>()
};
// This needs to go to persistent storage somewhere
// as subsequent requests may not come back to this
// webserver
result.SaveToADatabaseSomewhere();
System.Threading.Tasks.Task.Factory.StartNew(() => ProcessFoo(fooId));
return View("MyFooStartView", fooId);
}
throw new InvalidOperationException();
}
private void ProcessFoo(Guid fooId)
{
// Perform your long running task here
FooResult result = GetFooResultFromDataBase(fooId);
result.HasFinishedProcessing = true;
result.Uris = uriListThatWasCalculatedAbove;
result.SaveToADatabaseSomewhere();
}
public ViewResult CheckFooFinished(Guid fooId)
{
if (Request.IsAjaxRequest())
{
FooResult result = GetFooResultFromDataBase(fooId);
if (result.HasFinishedProcessing)
{
// Clean up after ourselves
result.DeleteFromDatabase();
return View("MyFooFinishedView", result.Uris);
}
return View("MyFooFinishedView", null);
}
throw new InvalidOperationException();
}
private class FooResult
{
public Guid FooId { get; set; }
public bool HasFinishedProcessing { get; set; }
public List<string> Uris;
}
Hopefully that will give you a starting point.
you want to look at this
answer to your question is: [AsyncTimeout(3600000)]
see more here
Controller Timeout MVC 3.0
To use Async controllers your controller has to inherit from AsyncController:
public class WebsiteController : AsyncController
And then any Action using Asynchronous methods has to use the format of
public void ActionNameAsync(int param)
public ActionResult ActionNameCompleted(int param)
Where ActionName is the name of your action, and instead of the Async function use
AsyncManager.OutstandingOperations.Increment();
each time you start a new aysnchronous method and
AsyncManager.OutstandingOperations.Decrement();
when the method finishes, after all outstanding operations have completed it'll move along to the Completed function (make sure to specify the parameters you need for the completed function in the async function so it knows what to pass along)
AsyncManager.Parameters["param"] = "my name";
Then using the AsyncTimeout attribute would actually affect the function. I'm not sure what happens if you try to apply that attribute to a action that isn't in an async controller.
These changes wouldn't require changing any of the references to the action in the javascript and what not as you'd still just request 'ActionName' and it would look to see if there was the Async/Completed setup version and if not it'd look for just that normal action and use whichever it finds.