Email Sending .NET Core - email

I just want to have a function, which will be sending mail to different people.
I have written a Email Service, just like this:
public void SendEMail(EMail mail)
{
var body = JObject.FromObject(settings);
body.Merge(JObject.FromObject(mail));
GlobalTelemetry.TrackDependency("E-Mail Service", "Send", () =>
{
var result = AsyncHelper.RunSync(() => httpClient.PostAsync(azureFunctionUrl,
new StringContent(body.ToString(), Encoding.UTF8, "application/json")));
if (!result.IsSuccessStatusCode)
{
throw new InvalidOperationException(
$"E-Mail Service failed to send mails. Http Status {result.StatusCode}. Please check if the Url '{azureFunctionUrl}' is correct. Env: {Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT")}");
}
});
}
and by every other functions, which want to use this mail service, do just like this:
SendMail = mail =>
{
var fireAndForgetTask = Task.Run(() =>
{
try
{
eMailService.SendEMail(mail);
}
catch (Exception e)
{
Log.Fatal(e, $"Fail to send E-Mail to: '{mail.To}'");
}
});
};
it does work, but fireAndForgetTask is not used, I have no idea how to do it better.
Is it necessary to write a Email Job???
Some better suggestion is welcome :-)

I had a similar issue in my app for sending a password reset email, I did not want the delay of waiting for the email to send because if a hacker is trying to find out if an account exists for an email address the delay could indicate that the account does exist. So I wanted to fire and forget the email with no delay.
So I implemented a simple extension method named forget like this in a separate static class based on this so question:
public static void Forget(this Task task)
{
}
and then I send my email async and use that .Forget extension to not wait for it like this:
emailSender.SendPasswordResetEmailAsync(
Site,
model.Email,
sr["Reset Password"],
resetUrl).Forget();
note that I am not using "await" when I call this async method and the .Forget gets rid of the warning that would otherwise appear in Visual Studio when calling an async method without the await keyword

Related

.NETCORE Middleware Read the Body value from the POST entered by a user in Postman AND Validate a particular value (To:) before sent

I am using a .NET CORE API application with Middleware but I need the Post to read the individual values from the Body in Postman AND have the Middleware Validate a particular value in the Body, for example, the (To:) of an email; and, if it meets whatever criteria I would like to (POST) send the email on to the intended recipient (To:) without a database.
This is what my code looks like so far
using (StreamReader streamReader = new StreamReader(httpContext.Request.Body, encoding: Encoding.UTF8, detectEncodingFromByteOrderMarks: false, bufferSize: bufferSize, leaveOpen: true))
{
await streamReader.ReadToEndAsync();
//Do something
////From test
if (evaluate.IsSenderFromConfiguration() == true)
{
message.From = From;
}
message.To = new List<MailboxAddress> { new MailboxAddress("mail#mail.com")};
message.Subject = "Message From Create Middleware";
message.HtmlBody = "This is just a test of Middleware ";
await SendEmailAsync(message);
httpContext.Request.Body.Position = 0;
}
await httpContext.Response.WriteAsync(body);
await _next.Invoke(httpContext);
}
Here is the Post from the Controller
[HttpPost]
public IActionResult Post([FromBody] Email email)
{
var message = new Email(_message.From, _message.To, _message.Subject, _message.HtmlBody);
if (message == null)
{
return NotFound();
}
return Ok(message);
}
Right now I just have what I did in the Get to send the email. How can I have it to where the properties message.To, message.From, etc. can be set by the User/Me in Postman and if the value in message.To is valid send the email?
I think there is a way to use the httpContext.Request.Body somehow, but I don't know how in .NET Core to set each individual value separately outside of the Middleware class.
To clarify: My Post Controller DOES NOT WORK FOR FORM VALIDATION The Middleware should be doing the work and then passing it to the controller once validated. That is where I need the assistance for the Middleware class.
use FluentValidation
also use in middleware like below:
services.AddMvc(setup => {
//...mvc setup...
}).AddFluentValidation();

xamarin forms: Calling phone and sending email (IOS, Android and UWP)

Currently using following code for calling and email features, but it is only working in Android and not working in IOS. Also, I need these features in UWP.
For call:
string phoneno = "1234567890";
Device.OpenUri(new Uri("tel:" + phoneno));
For mail:
string email = "sreejithsree139#gmail.com";
Device.OpenUri(new Uri("mailto:" + email ));
Any package available for this?
Xamarin.Essentials (Nuget) is available as a preview package and contains functionality to both open the default mail app and attach information such as the recipients, subject and the body as well as open the phone dialer with a certain number.
There is also a blog post about Xamarin.Essentials available on blog.xamarin.com.
Edit:
As for your mail issue, Xamarin.Essentials expects an array of strings as recipients so you are able to send mail to multiple people at once. Just pass a string array with one single value.
var recipients = new string[1] {"me#watercod.es"};
If you're using the overload that expects an EmailMessage instance, you are supposed to pass a List of string objects.
In that case, the following should work:
var recipients = new List<string> {"me#watercod.es"};
Updating the complete code for calling and mailing features using Xamarin.Essentials, this might help others.
For call:
try
{
PhoneDialer.Open(number);
}
catch (ArgumentNullException anEx)
{
// Number was null or white space
}
catch (FeatureNotSupportedException ex)
{
// Phone Dialer is not supported on this device.
}
catch (Exception ex)
{
// Other error has occurred.
}
For Mail:
List<string> recipients = new List<string>();
string useremail = email.Text;
recipients.Add(useremail);
try
{
var message = new EmailMessage
{
//Subject = subject,
//Body = body,
To = recipients
//Cc = ccRecipients,
//Bcc = bccRecipients
};
await Email.ComposeAsync(message);
}
catch (Exception ex)
{
Debug.WriteLine("Exception:>>"+ex);
}
Hello to make a call in UWP:
if (Windows.Foundation.Metadata.ApiInformation.IsTypePresent("Windows.ApplicationModel.Calls.PhoneCallManager"))
{
Windows.ApplicationModel.Calls.PhoneCallManager.ShowPhoneCallUI("123", "name to call");
}
To send a Text:
private async void ComposeSms(Windows.ApplicationModel.Contacts.Contact recipient,
string messageBody,
StorageFile attachmentFile,
string mimeType)
{
var chatMessage = new Windows.ApplicationModel.Chat.ChatMessage();
chatMessage.Body = messageBody;
if (attachmentFile != null)
{
var stream = Windows.Storage.Streams.RandomAccessStreamReference.CreateFromFile(attachmentFile);
var attachment = new Windows.ApplicationModel.Chat.ChatMessageAttachment(
mimeType,
stream);
chatMessage.Attachments.Add(attachment);
}
var phone = recipient.Phones.FirstOrDefault<Windows.ApplicationModel.Contacts.ContactPhone>();
if (phone != null)
{
chatMessage.Recipients.Add(phone.Number);
}
await Windows.ApplicationModel.Chat.ChatMessageManager.ShowComposeSmsMessageAsync(chatMessage);
}
as found in Microsoft documentation here: Compose SMS documentation
==> So you can make (If not already done) a shared service interface in your Xamarin app, then the implementation with these codes in your UWP app...
To send an email:
To send an email in UWP, you can refer to the Microsoft documentation too:
Send Email documentation (UWP)
Using a plugin
Else you can use a Xamarin plugin:
documentation: Xamarin cross messaging plugin
Nuget: Nuget plugin package
In our app, we are doing the phone calling with a DependencyService.
Therefore in our PCL, we have
public interface IPhoneCall
{
void Call(string number);
}
On the iOS side, the following method does the calling:
public void Call(string number)
{
if (string.IsNullOrEmpty(number))
return;
var url = new NSUrl("tel:" + number);
if (!UIApplication.SharedApplication.OpenUrl(url))
{
var av = new UIAlertView("Error",
"Your device does not support calls",
null,
Keys.Messages.BUTTON_OK,
null);
av.Show();
}
}
If don't want to wait for the Xamarin essentials that is still in pre-release as of today, you can use this open source plugin. It works on iOS, Android and UWP. There is a sample from the github documentation :
// Make Phone Call
var phoneDialer = CrossMessaging.Current.PhoneDialer;
if (phoneDialer.CanMakePhoneCall)
phoneDialer.MakePhoneCall("+27219333000");
// Send Sms
var smsMessenger = CrossMessaging.Current.SmsMessenger;
if (smsMessenger.CanSendSms)
smsMessenger.SendSms("+27213894839493", "Well hello there from Xam.Messaging.Plugin");
var emailMessenger = CrossMessaging.Current.EmailMessenger;
if (emailMessenger.CanSendEmail)
{
// Send simple e-mail to single receiver without attachments, bcc, cc etc.
emailMessenger.SendEmail("to.plugins#xamarin.com", "Xamarin Messaging Plugin", "Well hello there from Xam.Messaging.Plugin");
// Alternatively use EmailBuilder fluent interface to construct more complex e-mail with multiple recipients, bcc, attachments etc.
var email = new EmailMessageBuilder()
.To("to.plugins#xamarin.com")
.Cc("cc.plugins#xamarin.com")
.Bcc(new[] { "bcc1.plugins#xamarin.com", "bcc2.plugins#xamarin.com" })
.Subject("Xamarin Messaging Plugin")
.Body("Well hello there from Xam.Messaging.Plugin")
.Build();
emailMessenger.SendEmail(email);
}

Sending an async email without await from a .Net core web service

I have a webservice .Net core2 that has certain methods that send an email. I have it working fine using smtpclient.sendemailasync.
public async Task<bool> SendEmailAsync(MailMessage email)
{
try
{
if (string.IsNullOrWhiteSpace(emailFrom)) email.From = new MailAddress(emailFrom);
using (SmtpClient client = getSMTPClientInstance())
{
await client.SendMailAsync(email);
}
return true;
}
catch (Exception ex)
{
Log.Error(ex, "Error sending email in EmailService.SendEmailAsync");
return false;
}
}
The only issue is that some SMTP servers take a little too long to respond. I want to set up the email, queue it and return without waiting for the result.
Just using an unawaited async is out for 2 reasons;
It is not reliable to continue a method outside a request context in asp
I need access to the database context of my entity framework to write a log
I have to allow for external or internal SMTP (my client specifies), so a collection folder is not a possibility - at least not without a service that manages it.
How could I achieve this? Do I need to write a service that manages this? If so, how would I do that inside my .Net Core App, keeping in mind that the service also needs to access the EF context to write a log
UPDATE
There is plumbing available in .NetCore DI especially for this. Refer to my additional answer below. Use IServiceScopeFactory
You can call the RegisterAsyncTask method on the Page object. That will signal the ASP.NET runtime you want to make sure these are finished before terminating the request context:
Example:
public void Page_Load(object sender, EventArgs e)
{
RegisterAsyncTask(new PageAsyncTask(LoadSomeData));
}
public async Task LoadSomeData()
{
var clientcontacts = Client.DownloadStringTaskAsync("api/contacts");
var clienttemperature = Client.DownloadStringTaskAsync("api/temperature");
var clientlocation = Client.DownloadStringTaskAsync("api/location");
await Task.WhenAll(clientcontacts, clienttemperature, clientlocation);
var contacts = Newtonsoft.Json.JsonConvert.DeserializeObject<List<Contact>>(await clientcontacts);
var location = Newtonsoft.Json.JsonConvert.DeserializeObject<string>(await clientlocation);
var temperature = Newtonsoft.Json.JsonConvert.DeserializeObject<string>(await clienttemperature);
listcontacts.DataSource = contacts;
listcontacts.DataBind();
Temparature.Text = temperature;
Location.Text = location;
}
https://www.hanselman.com/blog/TheMagicOfUsingAsynchronousMethodsInASPNET45PlusAnImportantGotcha.aspx
So, while I have marked an answer, there are a couple of options that are better solutions for my specific example. First is the option to use a library like hangfire to schedule tasks - although that is not technically an answer to the question.
The better solution in .net core is to use IServiceScopeFactory
With IServiceScopeFactory you can rescope a task so it doesnt go out of scope when the request is complete. I did the following directly in a controller (I later moved to using the hangfire approach, but this works). As you can see, the async task is fired off in a new unawaited thread while the controller code continues.
var task = Task.Run(async () =>
{
using (var scope = _serviceScopeFactory.CreateScope())
{
var service = scope.ServiceProvider.GetRequiredService<ApprovalService>();
await service.sendResponseEmailAsync(approvalInfo.ApprovalId, userID, approvalInfo.emailTo, approvalInfo.ccTo);
}
});

Do some work after the response in ASP.NET Core

I have an ASP.NET Core website, using EFCore.
I would like to do some work like logging to the database, but after having sent the response to the user in order to answer faster.
I could do it in a different thread, but due to async access of the DbContext I am not sure it is safe. Is there any recommended way to do that?
public async Task<IActionResult> Request([FromForm]RequestViewModel model, string returnUrl = null)
{
try
{
var newModel = new ResponseViewModel(model);
// Some work
return View("RequestView",newModel)
}
finally
{
// Some analysis on the request
// I would like to defer this part
await Log(model);
}
}
One of the reason is that I would like to call a web-service (geocoding), which is not needed to answer, but good to work on the log (I need the city/country of coordinates).
I see this has never been answered, but actually have a solution.
The simple solution:
public async Task<IActionResult> Request([FromForm]RequestViewModel model, string returnUrl = null)
{
try
{
var newModel = new ResponseViewModel(model);
// Some work
return View("RequestView",newModel)
}
finally
{
Response.OnCompleted(async () =>
{
// Do some work here
await Log(model);
});
}
}
The secure solution, as OnCompleted used to be called before the response being sent, so delaying the response:
public static void OnCompleted2(this HttpResponse resp, Func<Task> callback)
{
resp.OnCompleted(() =>
{
Task.Run(() => { try { callback.Invoke(); } catch {} });
return Task.CompletedTask;
});
}
and call Response.OnCompleted2(async () => { /* some async work */ })
Building on Jeans answer and a question and answer on the try - return - finally pattern, the try and finally blocks can be removed (if you don't really want to catch an exception).
This leads to the following code:
public async Task<IActionResult> Request([FromForm] RequestViewModel model, string returnUrl = null)
{
var newModel = new ResponseViewModel(model);
// Some work
Response.OnCompleted(async () =>
{
// Do some work here
await Log(model);
});
return View("RequestView", newModel);
}
There's no out of the box way to do what you want.
But, here's a possible approach:
Have a queue and a worker (thread or process)
Just before the request is sent back to the client, add a message in that queue
The worker will pick up that message at some point in the future, and process it.
Since the worked runs somewhere else and not on the request thread, the server can complete the request thread and the worker can do what's left.
Try using Hangfire. Hangfire is an easy way to perform background processing in .NET and .NET Core applications. No Windows Service or separate process required.
Backed by persistent storage. Open and free for commercial use.
You could do something like
var jobId = BackgroundJob.Enqueue(() => Log(model));
And here is my blog post on using HangFire in ASP.NET Core
Create a new class that inherits from ActionFilterAttribute, overwrite the OnResultExecuted method to perform the logging and then apply your attribute class to the controller actions you want to do logging.

Parse.com resend verification email

I am using the email verification feature that Parse offers and would like my users to be able to resend the email verification if it fails to send or they cannot see it. Last I saw, Parse does not offer an intrinsic way to do this (stupid) and people have been half-hazzerdly writing code to change the email and then change it back to trigger a re-send. Has there been any updates to this or is changing the email from the original and back still the only way? Thanks
You should only need to update the email to its existing value. This should trigger another email verification to be sent. I haven't been able to test the code, but this should be how you do it for the various platforms.
// Swift
PFUser.currentUser().email = PFUser.currentUser().email
PFUser.currentUser().saveInBackground()
// Java
ParseUser.getCurrentUser().setEmail(ParseUser.getCurrentUser().getEmail());
ParseUser.getCurrentUser().saveInBackground();
// JavaScript
Parse.User.current().set("email", Parse.User.current().get("email"));
Parse.User.current().save();
You have to set the email address to a fake one save and then set it back to the original and then parse will trigger the verification process. Just setting it to what it was will not trigger the process.
iOS
if let email = PFUser.currentUser()?.email {
PFUser.currentUser()?.email = email+".verify"
PFUser.currentUser()?.saveInBackgroundWithBlock({ (success, error) -> Void in
if success {
PFUser.currentUser()?.email = email
PFUser.currentUser()?.saveEventually()
}
})
}
Poking around the source code for Parse server, there doesn't seem to be any public api to manually resend verification emails. However I was able to find 2 undocumented ways to access the functionality.
The first would be to use the internal UserController on the server (for instance from a Cloud function) like this:
import { AppCache } from 'parse-server/lib/cache'
Cloud.define('resendVerificationEmail', async request => {
const userController = AppCache.get(process.env.APP_ID).userController
await userController.resendVerificationEmail(
request.user.get('username')
)
return true
})
The other is to take advantage of an endpoint that is used for the verification webpage:
curl -X "POST" "http://localhost:5000/api/apps/press-play-development/resend_verification_email" \
-H 'Content-Type: application/json; charset=utf-8' \
-d $'{ "username": "7757429624" }'
Both are prone to break if you update Parse and internals get changed, but should be more reliable than changing the users email and then changing it back.
We were setting emails to an empty string, but found that there was a race condition where 2 users would hit it at the same time and 1 would fail because Parse considered it to be a duplicate of the other blank email. In other cases, the user's network connection would fail between the 2 requests and they would be stuck without an email.
Now, with Parse 3.4.1 that I'm testing, you can do (for Javascript):
Parse.User.requestEmailVerification(Parse.User.current().get("email"));
BUT NOTE that it will throw error if user is already verified.
Reference:
http://parseplatform.org/Parse-SDK-JS/api/3.4.1/Parse.User.html#.requestEmailVerification
To resend the verification email, as stated above, you have to modify then reset the user email address. To perform this operation in secure and efficient way, you can use the following cloud code function:
Parse.Cloud.define("resendVerificationEmail", async function(request, response) {
var originalEmail = request.params.email;
const User = Parse.Object.extend("User");
const query = new Parse.Query(User);
query.equalTo("email", originalEmail);
var userObject = await query.first({useMasterKey: true});
if(userObject !=null)
{
userObject.set("email", "tmp_email_prefix_"+originalEmail);
await userObject.save(null, {useMasterKey: true}).catch(error => {response.error(error);});
userObject.set("email", originalEmail);
await userObject.save(null, {useMasterKey: true}).catch(error => {response.error(error);});
response.success("Verification email is well resent to the user email");
}
});
After that, you just need to call the cloud code function from your client code. From Android client, you can use the following code (Kotlin):
fun resendVerificationEmail(email:String){
val progress = ProgressDialog(this)
progress.setMessage("Loading ...")
progress.show()
val params: HashMap<String, String> = HashMap<String,String>()
params.put("email", email)
ParseCloud.callFunctionInBackground("resendVerificationEmail", params,
FunctionCallback<Any> { response, exc ->
progress.dismiss()
if (exc == null) {
// The function executed, but still has to check the response
Toast.makeText(baseContext, "Verification email is well sent", Toast.LENGTH_SHORT)
.show()
} else {
// Something went wrong
Log.d(TAG, "$TAG: ---- exeception: "+exc.message)
Toast.makeText(
baseContext,
"Error encountered when resending verification email:"+exc.message,
Toast.LENGTH_LONG
).show()
}
})
}