Question

OK so im trying to create a settings class to store certain strings that i need to access throughout the system. I have created a globalSettings.cs with the code below:

public class GlobalSettings {     private readonly Hashtable myHT;      public GlobalSettings()     {         //Hashtable used to store global strings         myHT = new Hashtable();         myHT.Add('logCategory','TMBC'); //event log category         myHT.Add('logSource', 'MVC'); //event log source           //setup required options          //Create log source if required         if (!EventLog.SourceExists(myHT['logSource'].ToString()))         {             EventLog.CreateEventSource(myHT['logSource'].ToString(), myHT['logCategory'].ToString());         }      }      public string getSetting(string key)     {         return myHT.ContainsKey(key) ? myHT[key].ToString() : null;     } } 

At the moment i have initialised this class in each one of my controllers with the following:

protected GlobalSettings globalSettings = new GlobalSettings(); 

**Should i set the constructor to private and implement the singleton pattern as it is afterall a settings class and only need one instance?

Would i be better off extending the controller class with the setting information in it?

**

Answer 1

Personally, I’d rather compartmentalize those things. For example, why do all your controllers need to know about writing event logs? I’d have a single LogWriter class and ILogWriter interface, and use dependency injection (see MVCContrib for samples) – i.e.

class FooController : Controller {     private readonly ILogWriter logWriter;     public FooController(ILogWriter logWriter) {         this.logWriter = logWriter; // <==== edited for clarity     } } 

(and using a DI-based controller-factory)

This allows you to unit test the log-writing by mocking the log-writer. Then the settings would fit reasonably well as constants (or fetched from config) inside the LogWriter class.

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Re the specific question; if all the values are constant, use constants (or maybe static properties):

public static GlobalSettings {     public static const string LogCategory = 'TMBC'; //event log category     public static const string LogSource = 'MVC'; //event log source } 

A dictionary would be useful if they are fetched from configuration; if they are truly global, a static dictionary should suffice – instances would only be useful if it changes between impressions. A singleton would serve no purpose here; use static members instead.