Re: [Webmacro-devel] ContextTool improvements

[Lane S. <la...@op...>]

I know where you are at about the statelessness and the object creation 
overhead. Based on what I have been reading, I think we should support all.

1) objects in the context on demand w/context (like the tool model).
2) static functions in the context on demand (we have this in global 
functions now)
3) static functions in the context on demand w/ a context argument.(your 
new proposal)

I don't think one size will fit all. I fully recognize the value of 
statelessness, flyweight classes.

Lane

Keats wrote:

>Lane,
>
>This is precisely the way context tools work now.  The problem is that this
>requires a new instance of the tool to be created for each request.  If you
>supply the context with each method call, the class becomes stateless and
>therefore you only need a single instance (or no instance if you use static
>methods).
>
>This is the way functional programming works.  Generally, with object
>oriented programming you store the state in object and this give you a clean
>abstraction.  However, in this case there is a performance hit with so much
>object creation.  By hiding the context argument from the script we can have
>the best of both worlds to some extent -- a shareable stateless class,
>without all the extra parameter passing.
>
>Keats
>
>----- Original Message -----
>From: Lane Sharman
>To: Keats
>Cc: Brian Goetz ; web...@li...
>Sent: Monday, July 21, 2003 6:14 PM
>Subject: Re: [Webmacro-devel] ContextTool improvements
>
>
>Access to the Context is a terrific idea but isn't it better to something
>like this:
>
>
>class StatefulTool implements ContextStateful {
>    Context wc;
>    public void init(Context context) { // the ContextStateful interface
>       wc = context;
>   }
> public String localize(java.util.Date date){
>        return java.text.DateFormat.getDateInstance(
>            java.text.DateFormat.SHORT,
> wc.getRequest().getLocale()).format(date);
> }
>}
>
>
>When the class is references by the web script, its ContextStateful
>interface is handled by the context class itself:
>
>if (tool == null) {
>    String toolClass = loadables.get(name);
>    Object o = Class.forName(toolClass).newInstance();
>    if (o instanceof ContextStateful) {
>        ((ContextStateful) o).init(this)
>    }
>}
>
>It seems to me that every method of a tool and its intance should have a
>reference to the context on an explicit basis by declaring an init() method.
>That, at least, is my take, Keats.
>
>-Lane
>
>
>  
>

-- 
Lane Sharman
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