Question

I was using .Net Reflector on an Internal App to try and understand what the previous Dev was doing and also to learn. I have never had actual instruction on how to develop Apps so I take from where I can (Hooray Stack Overflow). That being said I found something that has me confused. A class Library called WinConstant containing the below code.

Here are my actual question:

1. What possible use could this be?

2. What value is there in storing a bunch of constant’s in a class library?

3. Is this considered a ‘Best Practice’?

Thoughts and guidance appreciated!

 Public Class clsConstant     Public Const cAccess As String = 'Access'     Public Const cAddress As String = 'Address'     Public Const cCancel As String = 'Cancel'     Public Const cCity As String = 'City'     Public Const cClear As String = 'Clear'     Public Const cClickOnMessage As String = 'Click on any row in top pane to see the detail fields in the bottom pane.'     Public Const cClientID As String = 'ClientID'     Public Const cColon As String = ': '     Public Const cComma As String = ','     Public Const cContactID As String = 'ContactID'     Public Const cCounty As String = 'County'     Public Const cDash As String = '-'     Public Const cDelete As String = 'Delete'     Public Const cDepartment As String = 'Department'     Public Const cError As String = 'Error'     Public Const cExec As String = 'Exec'     Public Const cFalse As String = 'False'     Public Const cFavorite As String = 'Favorite'     Public Const cFederal As String = 'Federal'     Public Const cFriday As String = 'Friday'     Public Const cfrmMain As String = 'frmMain'     Public Const cfrmModuleLogin As String = 'frmModuleLogin'     Public Const cfrmModuleSplash As String = 'frmModuleSplash'     Public Const cHelp As String = 'Help'     Public Const cHint As String = 'Hint'     Public Const cImagePath As String = '../../image'     Public Const cIn As String = 'In'     Public Const cInformation As String = 'Information'     Public Const cInitialScreenID As String = 'InitialScreenID'     Public Const cInsert As String = 'Insert'     Public Const cJuvenileID As String = 'JuvenileID'     Public Const cLetter As String = 'Letter'     Public Const cManual As String = 'Manual'     Public Const cMasterID As String = 'MasterID'     Public Const cModuleID As String = 'ModuleID'     Public Const cModuleName As String = 'ModuleName'     Public Const cMonday As String = 'Monday'     Public Const cName As String = 'Name'     Public Const cNegative As String = 'Negative'      _     Public Shared ReadOnly cNLowDate As DateTime = New DateTime(&H851055320574000)      _     Public Shared ReadOnly cNullDate As DateTime = New DateTime     Public Const cNullDateString As String = '12:00:00 AM'     Public Const cOfficeIDDefault As String = '01'     Public Const cOne As Integer = 1     Public Const cOut As String = 'Out'     Public Const cPopUp As String = 'PopUp'     Public Const cPositive As String = 'Positive'     Public Const cProcess As String = 'Process'     Public Const cProviderID As String = 'ProviderID'     Public Const cQuestion As String = 'Question'     Public Const cRead As String = 'Read'     Public Const cReferralID As String = 'ReferralID'     Public Const cReminder As String = 'Reminder'     Public Const cReport As String = 'Report'     Public Const cReportEngine As String = 'ReportEngine'     Public Const cReportEnginePath As String = 'ReportEnginePath'     Public Const cReportingServices As String = 'ReportingServices'     Public Const cReportServer As String = 'ReportServer'     Public Const cReportService As String = 'ReportService'     Public Const cReportServiceLocal As String = 'ReportServiceLocal'     Public Const cReportServiceServer As String = 'ReportServiceServer'     Public Const cSaturday As String = 'Saturday'     Public Const cSearch As String = 'Search'     Public Const cSelect As String = 'Select'     Public Const cSpace As String = ' '     Public Const cSQLLoginError As String = 'SQL Server login/password invalid'     Public Const cStart As String = 'Select a module'     Public Const cState As String = 'State'     Public Const cSubjectID As String = 'SubjectID'     Public Const cSunday As String = 'Sunday'     Public Const cThursday As String = 'Thursday'     Public Const cTooltipCancel As String = 'Reset form data values back to before all manual changes.'     Public Const cTooltipClear As String = 'Clears all data entry fields prior to an Insert'     Public Const cTooltipClient As String = 'Display a Client popup window.'     Public Const cTooltipClose As String = 'Close this form'     Public Const cTooltipDelete As String = 'Delete the current record being displayed, no undo possible.'     Public Const cTooltipExe As String = 'Initiate a batch process.'     Public Const cTooltipInsert As String = 'Insert a brand new record'     Public Const cTooltipSearch As String = 'Perform a Search for values entered.'     Public Const cTooltipSelect As String = 'Perform a Select for values entered.'     Public Const cTooltipUpdate As String = 'Update an existing record'     Public Const cTrue As String = 'True'     Public Const cTuesday As String = 'Tuesday'     Public Const cUnderscore As String = '____________________________________________________________'     Public Const cUpdate As String = 'Update'     Public Const cWarning As String = 'Warning'     Public Const cWeb As String = 'Web'     Public Const cWednesday As String = 'Wednesday'     Public Const cWorkerID As String = 'WorkerID'     Public Const cZero As Integer = 0     Public Shared strLongDate As String() = DateAndTime.Now.ToLongDateString.Split(New Char() { ','c })     Public Shared strModuleMainStatusStripFormID As String = Nothing End Class 

Answer 1

Back in the days of coding windows applications in c, there were similar files #included in windows which consisted of long lists of #defines creating constants. Various c applications emulated this approach in their own files. The ‘class’ seems to be a ‘transliteration’ of this ‘c-ism’. The fundamental principle of Object Oriented Design is to mix code and data into related functional units: objects. As jfullerton wrote:

From a programming point of view, object-orientation involves program objects, encapsulation, inheritance, and polymorphism. The conceptual objects are modeled in the program code. Encapsulation keeps an object’s data and methods that use the data together as part of the object.

So clearly, this constant list does not conform to OO practices but is a throw back to the old days.

To answer your questions:

1. — This class holds constants, that is it
2. — The old developer probably did this because that was what he was used to doing
3. — It’s not current best practices.

Naturally, if this is part of your application, you can’t just throw this away. Rather, this is something to refactor over time, assuming you use current best practices of Test Driven Development and Refactoring