c# - Use Decorator Pattern for asp.net controls -

i've created custom textboxes inherited textbox. next step want register javascript wrapper.

decorator pattern allow me if can inherit textbox , pass custom textbox constructor parameter.

problem how can use constructor when add control aspx page or how can use decorator pattern asp.net controls.

edit:

simply validation base class (ifield validation interface. can ignored):

public abstract class validationbase : textbox, ifield {     private readonly ifield _field;     protected validationbase(ifield field)     {         _field = field;     }      public int minlength     {         { return _field.minlength; }         set { _field.minlength = value; }     }      public bool required     {         { return _field.required; }         set { _field.required = value; }     }      // other porperties etc...      protected override void onprerender(eventargs e)     {         // stuff...          base.onprerender(e);     } } 

and concrete class (emailfield concrete impl. of ifield ignore...):

public class validationemail : validationbase {     public validationemail()          : base(new emailfield(string.empty))     {     } } 

and want implement (i've made mind on wordpad can't exact impl.):

public class jsregisterdecorator : validationbase {     private readonly validationbase _validationobj;      //i not quite sure constructor can handle     public jsregisterdecorator(validationbase concretevalidationobj)          : base(concretevalidationobj)     {         _validationobj = concretevalidationobj;     }      //wrap properties      protected override void onprerender(eventargs e)     {         //register js files...         _validationobj.onprerender(e);     } } 

the problem how can use decorator? because asp.net construct controls automatically:

<vc:validationemail id="validationemail1" runat="server"/> 

i don't know can use (where can put constructor parameter?):

<vc:jsregisterdecorator id="validationemailwithjs1" runat="server"/> 

i don't think decorator pattern fits here. in general saw more applications of builder , factory method asp.net controls.

to partially solve task can use controlbuilder. give ability change type of control validationbase jsregisterdecorator or validationemail. need decorate validationbase class controlbuilderattribute, inherit builder class controlbuilder , override init method.

[controlbuilder(typeof(validationbasebuilder))] public abstract class validationbase : textbox, ifield { }  public class validationbasebuilder: controlbuilder {     public override void init(templateparser parser, controlbuilder parentbuilder, type type, string tagname, string id, system.collections.idictionary attribs)     {         var newtype = typeof(/*here can put jsregisterdecorator type*/);         base.init(parser, parentbuilder, t, tagname, id, attribs);     } } 

but i'm not sure such approach. controlbuilder cannot give easy control on constructor. surely can override processgeneratedcode in controlbuilder , david ebbo has blog post worth reading not easy task rewrite constructor control , make solution simple.

as alternative work can suggest add abstract (or virtual) method registerscripts inside validationbase , call in onprerender. every control know scripts needs , process of new validator control creation clean , simple. if want separate knowledge of js scripts concrete implementations approach seen in asp.net dynamicdata (read metatable) used.

another thing can see idea close enough dynamiccontrol , maybe possible more ideas asp.net dynamicdata field templates , ifieltemplatefactory.