Jaycent Drysdale

  • asp.net mvc page compression

    Looking for a great way to reduce page size and reduce bandwith usage on your asp.net mvc web application?
    consider looking into page compression. Below is the c# class that I used to knock my page size down from 44K to a measly 6K...thus saving on bandwidth usage and page download time. 

    First, you need to reference the following namespaces

  • List<t> paging via LINQ to Objects

    The various grid controls shipped with asp.net provides plug and play data paging on its underlying data source. Its quiet simple to get a paged view of your data by setting a few properties on the grid before calling the Bind() method to connect your grid to the data.  This scenario works well in most situations. On occasions where the paging logic needs to reside outside of the UI layer, a more custom paging mechanism is required.

  • System.Data.GenericClient : A custom Data Access Component

    Developers often find themselves having to connect to data in a variety of datasources ranging from MS Access  to large scale relational databases such as Oracle, SQL Server, MySql etc. Each different datasource type typically requires importing a different .Net provider-specific namespace for working wth a specific database. For instance, to connect to an Oracle Database the consuming application needs to import the System.Data.OracleClient Namespace and untilize classes such as OracleCommand, OracleDateReader etcettera. To connect to SqlServer applications developers import the  System.Data.SqlClient namespace into their applications and program against the classes provided by the namespace.  The net effect of having multpile provider specific namespaces is that your DAL components are rarely ever portable, with each different database type normally requiring provider specific code.

    System.Data.GenericClient is a simple but generic custom built data access component that solves some of the issues outlined above. System.Data.GenericClient provides a very simple but familiar API that can be configured declaratively in an application configuration file as well as programmatically in your DAL. Below I'll take a look at using System.Data.Generic to connect to various datasources using a consistent API.

  • File System search via LINQ to Objects

    LINQ provides a standard way for developers to query data in diverse locations, ranging from in memory objects, XML data, or relational data living in an SQL Server Database.Lets take a look at a scenario where we use Linq to objects to query a directory on the local drive for files that match a given extension, and show the results in a Datagrid control.

  • Extension Methods: A simple example

    If you've been developing software for any significant lenght of time, chances are you have compiled(for want of a better word) a repository of helper functions that have, over time, become valuable to you as you make your way through various applications. Extension Methods allow us to extend our custom and existing CLR types to include new functionality. These new functionality might already exist in the form of helper functions scattered throughtout our applications. For example, You might have a helper function that converts a string value to Proper Case. Extension methods allow us to "add" this ToProperCase() functionality to the primitive System.String type as if it were a built in method of the type. 

  • Object Oriented Programming Refresher

    Recently I was challenged by a colleague who asked some very basic questions relating to object orient programming. I know these concepts very well, but sometimes you have to stop and think twice about them, especially if most often than not, you do not implement these concepts in your day to day programming activities. As developers, we often find ourselves in situations where the need to get things out the door and into production tend to encourage us to not think about doing things the right way, but instead, getting the work done in the least possible time.  Object Oriented concepts are something every serious developer should know inside out. Sure you can get by without practicing it, but that approach might come back to haunt you down the road.

    Classes are the foundation of Object Oriented Programming. Business Logic code should be seperated into groups of related classes that satisfy a business need. There should be a clear seperation of concerns. When planning a development strategy for our applications, we should at all times try to envision our applications as being seperated into three logical tiers. Strictly speaking, having three logical tiers doesnt dictate that our apps must to be deployed physically as a three tier app...all the tiers could live on one one physical machine, or they could be deployed accross three different machines. They could also be deployed on multiple machines in the enterprise, in what is known as an n-tier architecture.  Our apps will perform much better when we distribute the processing requirements accross multiple machines...business logic components run on machine A, Data Access components run seperate machine, and the front end logic running on a clinet pc or web server somewhere else. Microsft Transaction Server, and now Enterpise Services can act as a broker for our components living in the data access and business logic tiers, and offer such services as transactions support, object pooling, which promotes better scaling applications.

    So, what is an abstract class. What is a sealed class. What is the difference accessibility methods out there that I can apply to my classes and methods, and why do I need them? What are interfaces? when is it useful to use an interface? These are the questions that rolled through my head when I was first introduced to OOP years ago. Over time, as you develop more business level applications, the importance of these concepts become clearer.

    Inheritance is a pupular term among the OOP purists. So what is Inheritance, and how does it relate to OOP? Perhaps the best way to describe this would be to imagine a hypothetical situation where you are building an app that requires you to Mainatin a list of employee records. All employees must have an employeeID, they must have a first name, and they must have a departmentID etc. In addition, there are some employees that work on a part-time basis, and some that work full-time.

    Looking at the above scenario, we have indentified the need for an employee class to service our application. but before we start building our employee class, we need to take a closer look at how that class will be implemented. There are common features that all employees have, but there are also some features that are specific to  the full-time employee and others that are specific to the part-time employee. For instance, when we calculate the monthly pay for the full-time employee, the logic might be different from what we do when we calculate the salary of the guy that is employed part-time.  It might help if we define a baseline Employee class that contain the common functionality, properties etc, and then further extend these classes in other derived classes to inplement the specific functionality. So at the root, we might create an employee class,  and two derived classes: FullTimeEmployee and ParttimeEmployee. Both these classes will be based on the base Employee class and will inherit any functionality exposed, but will further provide indiviual methods that will be used to calculate an employee's salary.

    By marking our employee class as Abstract, we are marking it as a class that cannot be instantiated directly...we are saying that this class exists only to be further refined through inheritance. The exact opposite scenario to that would be to mark our class as sealed, which would mean it cannot be further refined through inheritance.

  • Anticipated new Data Types in Microsoft SQL Server 2008

    The next release of Microsoft SQL server, version 2008, promises a number of significant changes over its previous 2005 version release.  From a Developers perspective, there is much anticipation over the new data types that we will get to play with in our stored procedures and other database objects. I’ll go through some of the new data types in this post.

  • Options for Database access outside of ADO.Net

    In the world of .NET programming, ADO.NET has become the De Facto standard for accessing database of all types (relational or otherwise). The purists among us will be quick to point out that ADO.Net should be the only option and that as developers we shouldn’t even be thinking about bypassing ADO.NET to get to our database. But the no-so-pure will be quick to point out the alternative methods for pulling data from our databases without writing a line of database code. If you are still reading this article, it means you, like your truly have had occasions in the past where bypassing ADO.Net makes sense, whether you are creating a small website for your wedding guest list, or just putting together a demo website of sorts.

    The SqlDataSource Control:
    The SqlDataSource control (in my mind, the grand-daddy of declarative data Access) allows for the definition of queries in a declarative way. You can connect the SqlDataSource to controls such as the Datalist, and give your users the option to edit and update data without requiring any ADO.NET code.  While the sqlDatasource control handles the heavy lifting required to facilitate the communication, it's worth mentioning that behind the scenes, it uses ADO.NET to do this heavy-lifting. The sqlDatasource supports any database that has a full ADO.NET provider. Apart from the fact that the sqlDatasource connects you to your database with minimal code, it does provide more benefits to developers who are looking to provide functionality such as paging sorting of datagrids without having to write lines of code to achieve this. If you bind your datagrid directly to a sqlDatasource control, you have paging and sorting functionality right at your fingertips.  You can get to it by setting a few properties on your grid control. However, with all its "niceties" the SqlDataSource is somewhat controversial, because it encourages you to place database logic in the markup portion of your page. Many will agree that there are times when the benefits of using this control far outweigh this particular drawback.

    LINQ to SQL:
    Linq provides us with cool new way of accessing data.  The source of this data can range from anything from files in your computer file system, a collection of objects living in a generic list in server memory, or rows of data residing in a database table in on the North Pole. Linq comes in a variety of flavors (LINQ to objects, LINQ to XML, LINQ to entities, LINQ to SQL, LINQ to Dataset).  With LINQ to SQL, you define a query using C# code (or the LinqDataSource control) and the appropriate database logic is generated automatically. LINQ to SQL supports updates, generates secure and well-written SQL statements, and provides some customizability. Like the SQLDataSource control, LINQ to SQL doesn’t allow you to execute database commands that don’t map to straightforward queries and updates
    (such as creating tables). Unlike the SqlDataSource control, LINQ to SQL only works with SQL Server and is completely independent of ADO.NET.

    The profiles feature, introduced in .Net Framework 2.0, allows you to store user-specific blocks of data in a database without writing
    ADO.NET code.  You specify what data you want to gather and store by configuring the appropriate elements in your applications configuration file.