Web Application Development Tips, Tricks and Techniques
Entity Framework
Jan 31st
Entity framework is the new kid on the block on the ORM realm. It’s Microsoft new technology for data access, and although it didn’t receive very good comments on its first version, things have been greatly improved in its latest release. It now looks really interesting, with some features which surpass the most seasoned ORM frameworks that have been in the game for years.
Here’s what Entity Framework (EF) has to offer:
Persistance layer: object-relational mapping tools
Dec 13th
Nowadays it’s very usual to work with object-oriented programming and relational data bases. Relational data bases are all about tables, relations and groups. However, the object-oriented programming paradigm consists of objects, attributes and inter-object relationships. When these objects need to be stored using a relational data base, it’s very obvious that these two models of representing information are very different from each other. We need some kind of translation to transfer data from one to the other.
If we’re using objects in our application and we want to save them, we’ll probably use some data base system. We’ll most likely establish a connection to the data base, create a SQL sentence with the values of the object (or call some kind of stored procedure), and save them to some table. Easy enough, right? Well, this may seem trivial for a small object with 4 or 5 properties. Just consider an object not so small, with 40 or 50 properties. But… what happens with associations? And… what if the object itself contains some other objects? We’ll store them in the data base as well? All of them or just some? What will we do with foreign keys? We can see that, as the application gets more complex, this translation is not so trivial anymore… As a matter of fact, storing objects in the database can become a very usual source of headaches. There are some studies which state that up to 35% of code is dedicated to the role of translating data between the application and the data warehouse.
Parallel programming with .NET
Sep 26th
When I’m talking to people about the new things that Visual Studio 2010 and ASP.NET 4.0 bring, and the easy it is to write code to be executed in parallel, many people just don’t care. They see it as if it wasn’t related to them. It’s true that some kind of applications don’t really need this type of optimization… but that’s not an excuse to try to take advantage of our hardware as much as possible. From several years ago the most common thing in any computer is to have at least two processor cores. As a matter of fact, we’re starting to see now desktop computers with 8-core processors. The trend is to have an ever-increasing number of cores in our computers. This means that any application will have the chance to work in an environment where more than one thread can be executed simultaneously. Besides, nowadays if you want your software to perform faster, you can no longer just move it to a machine with a faster processor and forget about it. We’re approaching the maximum speed a processor can get, so improvements in next CPUs will come from the side of more threads, not a higher clock-rate. I think parallel programming is a key concept all programmers should care about. ASP.NET 4.0 and Visual Studio 2010 bring new libraries, types and tools to ease multi-core development. ASP.NET 4.0 includes the new “Parallel Extensions”, which are formed by:
Which database to use for a personal project?
Mar 24th
When starting a new project, the choice of which database to use usually boils down to the one the company usually uses. The systems that are usually considered are just Oracle and Microsoft’s SQL server (MS-SQL). There’s no doubt that big bucks companies have the resources to make the best-of-its-breed products, and almost no other database system comes close to what Oracle and MS-SQL can offer in terms of quality, features, and highly skilled professionals around their products. Yes, all this is true, but there’s a price. And usually this price tag can only be afforded by a company, not by a sole individual.
So, what if I want to develop my own personal project and I require a RDBMS (Relational DataBase Management System)? Oracle and MS-SQL are out of the question because of their high cost. MS-SQL Express has great limitations, so, although it is free, we won’t be considering it for our purpose. Which is the best open source RDBMS?
Unit testing
Aug 3rd
A unit test is a piece of code written with the sole intention of verifying that a routine or function behaves as we’re expecting it to. Unit testing attempts to provide a collection of tests to check every method of the different classes the developed program may contain works flawlessly. The general idea is that, if all the parts of the program work properly independently, it’s highly likely that the program as a whole will function as expected. Of course, after all the unit tests are passed, integration tests must be performed as well to ensure the complete system doesn’t have any unintended behavior.
HTML 5 C# Web Sockets server and ASP.NET client implementation
Jun 22nd
In the previous post we saw that Web Sockets are the best invention since sliced bread: they bring to the web the bidirectional full-duplex communication traditional desktop applications have been enjoying for quite some time now. It solves many current problems, and enables much more powerful applications than current standards.
I’ve developed a very basic Web Socket server implementation in C# just as a proof of concept. It handles the most basic operations you would expect from a server: start a new connection, disconnect, and send and receive data. Besides, I’ve developed the client part as well using regular ASP.NET. Actually it’s just plain HTML and JavaScript being served from an ASP.NET server – this example doesn’t use any fancy runat=server controls or anything of the like. The functionality is achieved with very simple and easy to understand JavaScript.
HTML 5 Web Sockets
May 30th
Following the series of posts discussing AJAX calls, today we’ll see what is going to be its evolution: Web Sockets. It’s still a very new technology, and support is starting to be implemented in most major browsers and web servers. But don’t count on using it yet, since most of the clients of your web app will not be able to use them. I’ll discuss web sockets here just so you know what the future is going to bring to the web apps world.
The history: the beginning of AJAX
The world wide web and the Internet started as a stateless content delivery mechanism, taking a step backwards compared to traditional desktop applications. Early Internet applications needed to explicitly request every piece of information, and the server sent only the requested data.
Then came what we now call “Web 2.0 application development”: Dynamic HTML, heavy usage of JavaScript, AJAX, and various plugins (Adobe Flash and Microsoft Silverlight). These applications were dynamic and responsive, and they brought much of that rich interactive experience users enjoyed in desktop client/server applications to the Internet. However, due to the request and response architecture that these applications are based on, the latest Rich Internet Applications still cannot match the connectivity and the capability to get real-time data that client/server applications had more than a decade ago.
AJAX call using ASP.NET Web Services
Apr 27th
We’ve already seen quite a few ways of performing AJAX calls: web pages, HTTP Handlers and Page Methods. Today we’ll see how to request data from the server using ASP.NET Web Services.
Web Services are a very general model for building applications, and can be implemented for any operation system that supports communication over the Internet. A Web Service is some programmable application logic accessible via standard Web protocols. It is often referred to as Web APIs as well, since they are a set of methods that provide some functionality through remote method calls. It is a way of offering some of your functionality to all of the internet. But, of course, some kind of restrictions and security can be built into your web services, if that’s what you wish.
AJAX call using an ASP.NET Page Method
Apr 6th
We’ve already been through AJAX calls using simple web pages and HTTP Handlers. But there’s still more ways to request data from the server. Today we’ll take a look at how to do so using server methods.
ASP.NET allows you to define methods in the code-behind of an ASPX page. This is very helpful in situations where you want to expose some specific server side functionality such as data retrieval for a specific page. If you need to make the operation available to multiple different .aspx pages it’s a better idea to use a web service so your pages can share the functionality. We’ll see how to use web services in the next post.
Please note that page methods must be declared as static, meaning a page method is completely self-contained, and no page controls are accessible through the page method. For example, if you have a textbox on the web form, there is no way the page method can get or set its value. Consequently any changes with regards to the controls have no affect on the page method. It is stateless and it does not carry any of the view-state data typically carried around by an ASP.NET page.
AJAX call using an ASP.NET HTTP Handler
Mar 23rd
We’ve already seen how to perform an AJAX call using just a simple ASP.NET web page. Now we’ll see how to do it with an HTTP handler instead of a web page.
But, what is an HTTP handler? Well, as its names suggests, it is an element that handles HTTP requests. Well, but that’s what an .aspx web page does, right? Sure, but in a lengthier, slower and resource-hungrier way. Regular web pages inherit from the System.Web.UI.Page class, which contains a lot of overhead and pre and post-processing in order to make it easier for the programmer to return HTML code to the client performing a request. In other words, the web page class has stuff to make it easier to develop a web page. It’s got some logic, doesn’t it?
My name is Oliver Mezquita Prieto, and I'm a Software Engineer focused on web application development, both serverside and clientside, using ASP.NET technology.
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