When Building a web application how many use the Singleton or Factory patterns when developing the app? What are the pros and cons using them for a web application?
I'm asking due to I'm looking at an asp.net web app that has 6 layers in the application and is using a mix of the singleton and factory patterns and to me, it looks like a tad bit of overkill for a web app that is just reading data from a database with
some business rules in the app.
Firstly, Singleton is one of the most mis-used patterns. I'm always sceptical when I see Singleton being used, and require some convincing that it is actually appropriate. In an IoC world, singleton-ness can often be achieved by using an appropriate lifetime
manager with the container.
When you say "Factory pattern" what do you mean?
There is no Factory pattern, per se. There is Abstract Factory and Factory Method, and the commonly used, but not GoF pattern, "Simple Factory".
Both Abstract Factory and Factory Method have their place - just look at the implementation of ADO.NET Managed Providers - and Simple Factory is extremely common. So I would expect to see these cropping up quite regularly.
After all, new is a horror keyword when it comes to building loosely-coupled applications, so some form of factory mechanism is often required in order to minimise its use.
csharpcoder
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559 Points
508 Posts
the use of patterns - singleton, factory
Feb 14, 2013 02:43 PM|LINK
When Building a web application how many use the Singleton or Factory patterns when developing the app? What are the pros and cons using them for a web application?
I'm asking due to I'm looking at an asp.net web app that has 6 layers in the application and is using a mix of the singleton and factory patterns and to me, it looks like a tad bit of overkill for a web app that is just reading data from a database with some business rules in the app.
DMW
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2353 Posts
Re: the use of patterns - singleton, factory
Feb 15, 2013 09:38 AM|LINK
Firstly, Singleton is one of the most mis-used patterns. I'm always sceptical when I see Singleton being used, and require some convincing that it is actually appropriate. In an IoC world, singleton-ness can often be achieved by using an appropriate lifetime manager with the container.
When you say "Factory pattern" what do you mean?
There is no Factory pattern, per se. There is Abstract Factory and Factory Method, and the commonly used, but not GoF pattern, "Simple Factory".
Both Abstract Factory and Factory Method have their place - just look at the implementation of ADO.NET Managed Providers - and Simple Factory is extremely common. So I would expect to see these cropping up quite regularly.
After all, new is a horror keyword when it comes to building loosely-coupled applications, so some form of factory mechanism is often required in order to minimise its use.
Dave