is there any way in MVC to get the System.Net.Mail SendAsync to work, instead of the blocking Send method?
I tried using it but hit the "Page starting an asynchronous operation has to have the Async attribute" error, which I obviously can't resolve (or can I?) because there is no ASPX page with an #Page directive where I could add the Async attribute.
Help is greatly appreciated :(
If you're using a third party service such as gmail to send your email and relying on SendEmail or SendAsync you may want to set up your own SMTP server which will then relay onto gmail. The benefit is that SendEmail will return much faster and you may be able to forget the whole async thing.
That way if gmail rejects you for whatever reason the email will still sit in your local queue.
This is a quick and dirty way to get somewhat reliable email sending setup.
Instructions (not personally tested, but i did this years ago*) or see this for Windows 7
*of course I only remembered i did this after spending a long time converting over to async :-(
It looks like you want Asynchronous support for ASP.NET MVC. See also "Extend ASP.NET MVC for Asynchronous Action".
This SO question is also relevant.
You may want to consider putting the email into a database table and then have a daemon that sends out emails by processing the queue.
a) if youre not sending billions of emails you can have a log of what you sent
b) you can resend if something fails.
depends how important these emails are, but if theyre important from a business standpoint and mustnt get lost then you should use this approach.
Related
I have an ASP.NET Web API server, that have to communicate with different applications on different platforms. And now I want to create a method that would be something like a callback: client application subscribes to it and waits until server fires a message.
Example:
Many users are waiting until new product will be available in store - they subscribe to this "event". When product arrives in store - every customer receives a message, which have to be handled in some case.
Users send a request "Subscribe"
Server receive a request "Product available!"
Server sends every user a message with product details.
User's application processes the message
I tried to find some information about callbacks or duplex in ASP.NET Web API, but the one advice - it's better to use WCF for this approach.
Solutions
In every client application create something like timer, that every N seconds sends a request "Is product available?" until gets "false". When the response will be true - send a message "Get product details". It's causes a lot of traffic and if there will be many clients with these timers - it would be something bad, isn't it?
Create a small callbacks-server (maybe WCF). But in this case would be a lot of problems with communication between this server and apps on different platforms.
Maybe there are some solution in ASP.NET Web API, that i missed.
If you have some ideas how i can solve this problem, please give me an advice.
Thanks for help.
Looks like you want push notifications from your server - which, in this case, can be achieved by combining SignalR with Web API.
Brad Wilson has a great example on this:
code here - https://github.com/bradwilson/WebstackOfLove
NDC Oslo talk explaining all this - http://vimeo.com/43603472
In short, whenever you add new item to the Web API, you can notify all the connected (subscribed) clients:
public void PostNewItem(ToDoItem item)
{
lock (db)
{
// Add item to the database
db.Add(item);
// Notify the connected clients
Hub.Clients.processItem(item);
}
}
SignalR will invoke the processItem function on the client.
Alternatively, you might want to look into JavaScript SSE and Web API PushStreamContent but that is much more low level and SignalR abstracts a lot of this type of stuff for you so it might be more complicated to deal with.
I blogged about this approach here http://www.strathweb.com/2012/05/native-html5-push-notifications-with-asp-net-web-api-and-knockout-js/
I need your help to solve next issue: I am developing MVC application and want to send instant messages between users. This message will ne standard - it's like notification. I am thinking about two optins:
use XMPP protocot, but I don't need the huge amount of options it could provide, I need just basic functionality I've discribed;
have some static array in MVC application with users invitations were send to and ajax function which will call controller action, check if user is in static list. If yes - make message visible on the page. And plus do page autoupdate. But I am not sure about this becouse array will be called very often.
What do you think, guys? Do you have any ideas? I will be very thankfull for any help!
You may take a look at SignalR.
Also checkout Jabbr which is built on SignalR:
https://github.com/davidfowl/JabbR
This is a chat application written by the author of SignalR David Fowler.
You can set jquery timer to update messages with ajax. And when user writes message , it can be saved in Cache or in database if you want to save it permanently.
There is a ton of data on this subject where you simply take the phone-number+#mobile-carrier.com and send a message, that is not what I am looking to do.
I want to send an SMS, from the command line, in this case, using php, but I would be happy to use bash, and will probably make it into an app or plug in for Safari eventually. Right now, a test case would suit me fine.
I would like to do something like this:
./sms 619-555-1212 "this is the message"
I don't need to receive the message back to the computer, this is a sending only agent.
The criteria that makes all the data I find on this not work, is that I want my correct from: number to show up. I have tried using the email gateway method and changing he from: headers, but it appears they are stripped at the gateway.
I don't mind paying a service to give me certain amount of SMS credits to make this happen. I want to avoid any hardware, where I would have to get a modem or otherwise to connect to my computer.
If I do use a service, something with an example of how to do so within their API would greatly appreciated. I feel this should take me no more than 15 minutes, but I am hours into research and not getting very far with all the little scripts out there that do nothing close to what I want to do.
Thank you very much and sorry that I don't understand this protocol to the best of my ability.
You can send with Twilio using cURL very easily since sending SMS is a simple POST request with three parameters. Here's an example of a bash script that makes calls but could be modified to use the SMS API instead. http://labs.twilio.com/bash/
(I work at Twilio)
you will need sms gateway like http://www.clickatell.com/ for that
You can use any gateway that charges you a few cents for every message sent. They have a simple REST API which requires a very little coding. They even provide you a sample example to get started.
I am building an MVC application (using the Zend Framework).
When users first register, the applicaiton sends them an email. My question is, where should I trigger this email from? The model or the controller? My thoughts are as follows:
In some ways, the model makes sense, since sending a registration email is part of my business logic. Users must click the link in the mail to validate their email address.
But by putting it in the model, I am 'encumbering' the model. The model's registerUser action is then only useful within the context of an application that needs emails sent for every registration.
Instead, by triggering the email from within the controller, my controller would be a litter 'fatter', but my model a little more 'fine grained'.
I have written an email service which actually configures and sends the email, and I think this is a good design decision. I am really just asking where I should be calling this service from.
Your thoughts are most appreciated!
According to Zend Framework's definition of MVC, you should put send the email from the controller:
Controllers...decide which view to display based on the user's request.
Models, on the other hand, contain:
...basic functionality behind a set of abstractions.
An email may be considered a "view" in that it displays information to the user. It is the controller's job to activate this "view."
In my opinion, I would want this in the model, as I would consider this an assumed process of the create user method, rather than any specific interaction with the user making the request.
In other words, since I would always want this email sent, regardless of the source of the request, I would identify this as a natural byproduct of the create user action, similar to a record being saved in a database.
You might want to look into using something like NServiceBus to queue messages to be sent to your Email Service.
This way you can have NServiceBus subscribe to an event that occurs and omit any manual firing of the email service etc.
Ultimately you want a failsafe way of ensuring your messages get to the intended people. This kind of framework will greatly help you ensure that this happens.
Alternatively you could store the emails to be sent inside your database and have your email service check the database queue every x minutes for new emails to send and omit the need for triggering the email sending.
Again, doing it this way will ensure at the least that the emails get sent. Should the network go down or some other disruption occur during the sending of each email you can simply leave them in the queue until the network comes back up.
I'm wondering how it's implemented in Gmail, that every time you receive e-mail, the list of mails is automatically refreshed. It looks like the server is sending some kind of event to the browser, but how is it possible? Or maybe it’s simle: the browser ask the server for new messages every let’s say 2 seconds? But it would probably kill the performance…
Anyone have some ideas?
EDIT: OK, so if it's the simple answer, how do they manage performance? When I send an email from an other account to the gmail account the view is "refreshed" almost instantly. You were saying about a simple function that returns true / false, but it must have some logic (db connection or reads some files). How they manage it?
See also: How is GMail Chat able to make AJAX requests without client interaction?
Dont know exactly which technoloy Gmail uses, but the concept is to open a channel - using reverse AJAX, comet or sprocket based techniques.
Think of it as the client requesting the server for data, but the server does not return for one minute unless it has new mail. Using this technique, the client can almost show the results in a real time manner and it does not have to poll every 2 secs. Makes sense?
gmail is, in fact, polling the server for updates. Not as often as every two seconds, though. That would be madness. A bit of testing with Tamper Data makes it look like maybe every 20 seconds, though there seem to be multiple events going through that confuse it a bit.
Regarding your edit, I imagine they might have a last-activity timestamp on the account tracking in their database, with the client polling query retrieving that via Ajax and comparing with its last sync to determine whether it needs to do a full update.
You have right with simple answer. Google Mail checking new messages on server via AJAX.
It must be some kind of ajax listener that get informations every X seconds.
I already set something like that for one of my projects. What I was doing is calling a function that was returning true or false. True if the page needed to be refreshed, false otherwise. Then if you have an update, you do another call to get the actual update. This way you don't have to refresh everything every time... but it's still intense on the server if you have a lot of users.
In other words and like chaos said, it's polling the server.