I am real ASP.Net beginner and I could use advice from someone wiser than me to give me direction where to look and what to learn.
I am working on ASP.Net/C# webapp for our dept (target .Net is 4.8).
In short: I need to update page for multiple users every time certain value changes in the code behind and do it as fast as possible
Long: There is mandatory feature I can't bypass. Situation: 50 users will be on the same aspx page, watching it. There will be field with certain value. (it can be text field or whatever element will help me to achieve this). Admins can change the value of this element by clicking one of the related buttons. If such event happens, it is absolutely crucial to reflect this change in all of the browsers simultaneously and as fast as possible. Miliseconds matters. (not my idea)
What would be the best way to achieve this?
Please excuse me if my question is too silly. I am not expecting some sample/solution code on such badly formulated question, just general direction where to look (what to learn) as I could not find any solution so far. There should be something since it kind of resembles auction system, you bid, others see it immediatelly and can take action.
thank you in advance
Your use case seems to fit well with the usage of signal-r.
Basically you need something which allows you to set a bidirectional communication between the client and the server, so that you are able to broadcast a message from the server to all the connected clients whenever something important happens on the server.
You can start from the official documentation. This topic is broad, so you need to first of all read the docs and play with some of the provided sample applications. The advantage of this framework for real time web applications is that it fits really well in the ASP.NET and ASP.NET core ecosystem.
Avoid any solution based on client polling of the server state, by doing so you will basically ddos yourself. A push-based solution (like the one offered by signal-r) is way more efficient.
There is an ASP.net C# web application through which we can get the recipient emails, time zone and their smtp server details in to the database.I have two requirements:
1. Consider a table in the database. When ever there is a change in the table, an email has to be sent. It is OK if we can constantly check the database every 5 minutes. It would be great if we can send it instantly but a delay is fine.
2. Sending emails automatically at 12 AM at their respective time zone.
I m familiar with C# programming. But kind of new to automatic scheduling stuff. This could sound like a basic question but it would be great if you can help. What is the best way to implement this - Web api or web services or WCF or windows services or combination of web api and task scheduler? Please let me know your thoughts. Also a small tip on how to implement this would be great.
You have an option of setting up trigger but I hate that approach as it will add overhead to your table tow insertion and not actually needed. I think you are in the right path by thinking about pooling. There is a nice little library in .net called hangfire which I find to be very useful to do scheduled task. It has pretty sophisticated reporting and almost all the time works really well. You can give it a try. But if you want to control things better writing a small windows service don't be that bad either. I think doing websevice either using webapi or wcf is a bit overkill here and might not fit purpose.
I'd like to create a webapplication that allows users to work with graphs. (Retrieve data related to nodes, create new ones, drag them, etc.) I thought it would be a good idea to store the data in a graph database (e.g. neo4j) and display it with some JS-Frameworks (e.g. http://cytoscape.github.io/cytoscape.js/).
Currently I'm not sure which web application technology I should use. Since one requirement is to use microsoft technologies wherever possible I thought it might be a good idea to go with ASP.NET in C#. However, during the first chapter of my ASP.NET book the following is mentioned:
it’s worth noting that ASP.NET is not the best platform for writing
complex, app-like client-side programs
So, which technology should I use to create my web application? Any recommendations?
Well,
from my experience, I think one of the JVM based languages like Java is a save bet, if not the most sexy one. And it works best with Neo4j, and Java 8 is really nice syntax-wise.
For JS-based frameworks, try Node.js and the Neo4j REST API, should work good, too.
I have been asked to build a small web application for one of our clients and think it might be a good opportunity to try out a different framework for building web applications. Most of the applications we build are based on asp.net web forms and we have no yet done anything in an MVC architecture but I am eager to start building web applications in a more structured manner with the right tools.
I have been researching things like asp.net MVC and the likes which look quite good but I am wondering is there anything to be said for using something like the Google AngularJS Framework.
If possible I would still like to be able to write my server side code using c# and I have not researched AngularJS enough to know if this is even possible, although I assume I could use web services.
Has anyone had any experience with developing an app using AngularJS and if so, how was it and can you point me in the right direction for some tutorials?
We have been developing a port of a Swing fat-client application in AngularJS for the last couple of months and I think it is worth recommending. As far as learning resources go, check out the official project site (and be sure to read the tutorial) and the mailing list (the authors are very helpful).
The good stuff:
great testability
the two-way data binding is a very powerful feature, and it can be extremely helpful once you "get it"
IMO the AngularJS templates are much less brittle than using data- attributes or "special" CSS classes to mark elements that do something
it greatly reduces the need for using jquery plugins, because implementing that functionality in AngularJS is very easy (stuff like trees, tabs, accordions, etc.)
The bad stuff:
the learning curve seems pretty steep (I didn't have much of a problem, but I've seen some people struggle with it)
validations in AngularJS suck for the time being (a new implementation is on the way)
not all libraries/jquery plugins play nicely with Angular and usually you have to wrap them
the API is still being polished, so expect breaking changes (not a big problem with frequent releases and very good changelog, though)
performance is OK up until several thousand bindings on a page - most of the time this is not a limitation, but there are cases when this could be a problem.
Some pointers (if you ever decide to learn AngularJS):
some people really overuse widgets. In my experience, it's much better to use HTML "partials" + services, and only use widgets sporadically.
read source code of the library - it's the best place to learn stuff about angular
no DOM manipulation in services/controllers
if you use css classes to bind to events, you are doing it wrong
+1 #psycho's answer
AngularJS is client-side framework, so you can use any language on the server. It's designed to work well together with jQuery, with big emphasis on testing...
Here are some resources you might find useful:
TUTORIAL: http://docs.angularjs.org/#!/tutorial
API DOCS: http://docs.angularjs.org/#!/api
Developer Guide: http://docs.angularjs.org/#!/guide
Some example apps:
http://cburgdorf.github.com/angular-todo-app
http://www.fluid.ie/angular/calculate/
http://hookercookerman.github.com/angularjs-todos/
http://paul-hammant.github.com/StoryNavigator/navigator.html
Adapter for SenchaTouch: https://github.com/tigbro/sencha-touch-angular-adapter
Adapter for jQ Mobile: https://github.com/tigbro/jquery-mobile-angular-adapter
Feel free to ask any question on mailing list !
We are still in beta, but there are already several internal apps at Google, powered by AngularJS.
UPDATE (26th July 2012):
AngularJS v1.0 has been released.
For some public AngularJS-powered apps, check out http://builtwith.angularjs.org
IMHO developing something for a client which they may have difficulty supporting is unprofessional. You have to bear in mind that it will be difficult for your client to hire experienced Angular professionals, or train their own people to climb that "steep learning curve". Also, so far the documentation is not that great. Can you easily, in a few moments, answer the question, "How can I connect my shiny Angular app to my client's database?" Can your client sometime in the future easily grab some existing code and adapt it to their potential future needs? Be honest.
Compare plain old reliable LAMP development to Angular. For a "small web application" I really believe that a professional should give his client something maintainable and simple.
It's not to say that Angular isn't cool and sexy etc etc. But you have your client's future maintainability to think about in addition to the latest framework fad. Tread lightly would be my recommendation. Build your own website with Angular first and see what you think before you bestow your fabulous new skills on some trusting client.
I remember reading this SO thread couple of months back with same question in my mind, and we decided to go ahead with AngularJS, and the best decision we made on this project yet.
We are using AngularJS + ASP.NET MVC4 REST WebAPI.
Most probalbly after such a nice client side Javascript MVC framework, you would only need REST API layer interacting with Business Logic Layer at server side, and no MVC at server Side (ASP.NET MVC/Spring/Structs would feel like old memories).
You will find Angular-UI good add-on (esp ng-grid)
Soon after our project finishes, we might put some of our directive we wrote for open source world.
I have been researching the merits of AngularJS for many months to utilize as a core framework for product I am creating.
There are many aspects of AJS that make it worth while to learn. Yes there is a bit of a learning curve but its well worth it, especially if you wish to have more control on client side capability.
JQuery manipulates the DOM at run time, whereas AJS situates itself within the JS rendering lifecycle. This allows you to teach the DOM new tricks by creating your HTML Elements and Attributes. This is very, very powerful. As what you are able to do is introduce new Element behaviors for whatever your purpose and need. In AJS these custom HTML Attributes/Elements are called Directives. With the ability to craft your own Directives, you are able to build functionality that the current HTML doesn't have, pushing out capabilities that will run on all modern browsers now and into the future. Of the many approaches to inducing new behavior, AJS appears to be the safest direction one could take due to how they have chosen to implement it.
There is a huge performance gain over JQuery in AJS.
I love the simplicity of the two-way data binding, and the separation of concerns in their client side MVC pattern, which as pointed out above provide great testability. There scope object is the glue between the View (HTML), the Model (your Data) and your custom Controllers. The scope provides access to parent attributes and can be isolated at the sibling level, which is important for some reusable templates.
Templates can created and reused across your application which can contain 0 or more custom directives.
I have been using frameworks such as PRISM and MEF but I am finding that AJS has most of the same features that exist in these .NET frameworks but in a 29K footprint. There is rumors that they are working on lazy-loading which if provided will provide for some very interesting LOB type capabilities.
There are a number of UI frameworks that are being built for AJS but you can wrap any 3rd party control lib as needed, given a bit of effort. The trick is to ensure that when these 3rd party controls have changes induced, that you ensure AJS is properly notified using their apply method.
If you combine AJS with MS TypeScript within VS 2012, it provides the ability to manage and build some very impressive projects which will work well for those who are more comfortable with projects within VS.
There are a ton of other reasons to look at AJS, but if you are considering frameworks such as KnockOut I'd highly recommend AJS instead, regardless of it's perceived learning curve. Knockout is a library, AJS is a framework.
So far i think Google's Angular is great. Particular like the databinding and dependency injection.
For other js framework, there are knockout.js , backbone.js etc.
here are some posts:
angular.js example in backbone.js and/or knockout.js
I realise this post is old and you haven't gone with Angular, but I have a similar background to you, and I'm at the same point as you when asking the question.
So for the benefit of future visitors, some of the "risks" and links to resources I've found useful...
As many have already mentioned, Angular can have a very steep learning curve "Not only me, but co-workers that I consider highly smart developers, have struggled with some of the basic concepts" AngularJS is amazing... and hard as hell (link also has some good tutorial links which you asked for), and the version 2 stuff is looking more like java, which wouldn't have been a problem with your C# background, in my opinion Directives are hard enough to understand without verbose annotations and so on.
Angular performance can be poor in some cases, especially when using ng-repeat on a large number of elements Considering Speed and Slowness in AngularJS and Scaylr's experience. Other's have mentioned that performance really degrades over ~2000 bound elements, but that's usually met with arguments about how any app with more than that many elements probably isn't a good app. Keep it in mind though if you have legitimate use cases which call for many bound objects.
Angular is popular in terms of contributors, but ranks way way behind, say, jQuery in terms of production usage. Finding Angular developers might be tough, and jQuery or other developers converting have that "steep learning curve" to deal with.
Because Angular is young, you have no guarantee that it'll gain enough traction for your new Angular skills to be employable, and your new application not to quickly become legacy code
In v1.2 Angular doesn't support IE7 and below and v1.3 will drop IE8. For >=IE9, you need to follow some special coding practices.
The many javascript widgets, plugins and libraries which you might be used to using can't be used properly with Angular without heavy modification and people often suggest to re-write your component in Angular anyway.
UPDATE March 2014: after 2 months attempting to build a non-trivial densely functional one page app: There are many versions of Angular, and it's hard to say which is the best or most stable. It will depend on what you're coding with it. I'm finding some bugs Angular that are fixed by upgrading to a later version and others fixed by regressing to an earlier one. I've never had to go version shopping like this with jQuery.
UPDATE May 2014: Young, broken tools. Batarang is great until it doesn't work. I can't trust it until they fix this one.
And finally, the three best resources I've found for learning this stuff
Todd Motto's ultimate guide, and
UPDATE April 2014: this eBook chapter is quite amazing. I didn't buy the rest of the book yet, but the concept is fantastic
A full non-trivial app written in Angular (the accompanying book is OK, but doesn't really talk about the non-trivial app enough, as they appear to be saying advertised on their site)
I would say yes to this and check out John Papa's hottowel implementation as a way to do it.
What is the status of ASP.NET/MVC technology? Would there be big changes that affect every code base? Is it stable (backward compatible) enough to be used in real world?
Best Regards
You know, the very site you're using.. Stack Overflow, was written in MVC. That should answer your question.
Yes, it is stable. Yes, it is production ready. It is used on this very same site. Depending on your existing code base there might or might not be big changes in order to port it to ASP.NET MVC 3.
Kaveh, I banned using MVC1 in my team because I am a late adopter but a fast adopter (agency work doesn't have time for discovering bugs on behalf of the creator).
Since MVC2 (and now including MVC3), I am very very keen for people to use it. There are some things about MVC that might be difficult if you've only ever worked in web forms, but if you understand http, and html, then it has cut away a lot of the annoying bulk in web forms.
MVC will quickly overtake Webforms in popularity.
MVC
requires less code in most cases.
MVC enables very easy integration
with other client side frameworks and now defaults to using jquery as a standard (in webforms, lightweight ajax usually requried a lot of custom code and quite a bit of repetition).
MVC generates almost no
garbage in your html output.
MVC is
long overdue, stable, secure and simply a
fantastic step in the right direction
for Microsoft.
I would only suggest you tread carefully with where you get your advice on how to do things and any use of 3rd party products like StructureMap that are not supported by Microsoft. I have seen some people make big mistakes with that combination, but never because of MVC.
There was little or no breaking changes from MVC2 - MVC3 unless you'd used certain approaches. I would actually say you are less likely to get breaking changes in future but any version upgrade in any platform will require some work if the changes are worth it.