T.J. is correct, of course, that my original suggestion would make multiple copies of the functions. That's what I get for writing off the top of my head. If I understand correctly, what joe t. really want is something like:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd";> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>SpecialDate</title> <script> var specialDateFactory = function () { var calcIsEaster = function () { // do something with _this_, which will be a Date object this.isEaster = true; // replace with real code } var calcIsLaborDay = function () { // do something with _this_, which will be a Date object this.isLaborDay = false; // replace with real code } return function () { var that = new Date(); that.calcIsEaster = calcIsEaster; that.calcIsEaster(); that.calcIsLaborDay = calcIsLaborDay; that.calcIsLaborDay(); return that; } } (); </script> </head> <body> <script> var myDate = specialDateFactory(); document.write("<p>myDate.isEaster: " + myDate.isEaster + "</p>"); document.write("<p>myDate.calcIsLaborDay: " + myDate.calcIsLaborDay + "</p>"); document.write("<p>myDate instanceof Date: " + (myDate instanceof Date) + "</p>"); </script> </body> </html> The factory function specialDateFactory returns a Date instance which has methods calcIsEaster and calcIsLaborDay, and properties isEaster and isLaborDay. If you change the value of the returned object, you can call calcEaster and calcIsLaborDay again to refresh .isEaster and .isLaborDay. What's more, the functions like calcIsEaster and calcIsLaborDay can call each other securely -- no matter how objects returned from specialDateFactory are abused, variables in the closure are undisturbed. So you can securely add lookup tables and helper functions hidden from the outside. And this introduces only one closure, so it's fairly cheap. JavaScript constructors are an anomalous, pseudo-classical things. If you're not going to compare objects with instanceof, don't bother with them. More often, factories are what you really want. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Prototype & script.aculo.us" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/prototype-scriptaculous?hl=en -~----------~----~----~----~------~----~------~--~---
