[Laszlo-user] overridding core class by inclusion

[Pierre Augier]

This is interresting .. i have to understand the core mechanism of OL :) 
so i have few questions again :

1) Do you know where are theses core JS library (ex LzView)  in the LPS 
server ? i didn't find them under /lps tree.
1bis) =>And who is doing the binding from LZX code to ECMA code ? i 
guess it's the OL compiler / servlet couple ?

2) Which object framework is used by OL ? prototype.js ?

another question about HCI design:
-3) Is it possible to have a MVC mechanism in OL ? I was thinking about 
declaring static my component in a sort of view, bind them in a JS 
library playing the role of the Controler, and then a model.
an example with a button that init and connect to a rtmp server (it's a 
draft)
-------------------------------------------------------------------------
<!-- the "view" myapp.lzx-->
<canvas>
<edittext id="edittextServerAddress" />
<button id="mybutton" >connect</button>

<script src="mycontroler.js">
...

<canvas/>
-------------------------------------------------------------------------
<!-- the "controler" mycontroler.js -->

//creating the model, ideally, the view would be created here too, but 
the view is the app entry point so i guess it have to be created first 
and then the view have to create the controller
var rtmpconn = new myrtmpconnection();

// binding view to controler

mybutton.onclick = function(button)
    {
            button.setAttribute('text','connecting ...');
            rtmpconn.setAttribute ... etc
            rtmpconn.myModelInitMethod(edittextServerAddress.text);
            rtmpconn.connect();
    }

// "controller classic" functions callable from "external"

function init(adress){

    ... code ...
    rtmpconn.myModelInitMethod(adress);
    ... code ...
}
-------------------------------------------------------------------------
<!-- the model "mymodel.lzx" -->
<library>

    <class name="myrtmpconnection" extends="rtmpconnection">

         <attribute name="myModelVar" />
          <method name="myModelInitMethod" args="adress"=> (code) </method>
    </class>

</library>

... hope that is clear ... the idea is to have a "real" agent MVC model 
... but that's maybe a bad/wrong way ?

thanks a lot

Pierre


Henry Minsky a écrit :
> I should add that there is a certain magic translation of core class 
> names
> from LZX to Javascript that is happening, so <view> actually 
> corresponds to
> the real class named LzView, same for most of the core classes that are
> user visible. The magic happens via the static var declaration in a 
> class called "tagname":
>
> class LzView extends LzNode {
> static var tagname = 'view';
> ..
>
>
> As Tucker said, if you redefine a core class like that, you do so at 
> your own risk,
> all sorts of things will probably break.
>
> On 7/10/07, *P T Withington* <ptw at openlaszlo.org 
> <mailto:ptw at openlaszlo.org>> wrote:
>
>     Welcome to dynamic languages.  Yes, it is allowed.  If you really
>     wanted to, you could replace the core classes too.  And, yes, it will
>     probably cause a problem if you do.
>
>     In general, Javascript emphasizes flexibility over safety.  IMO, Java
>     leans the other way.
>
>     On 2007-07-10, at 13:29 EDT, Pierre Augier wrote:
>
>     > I all !!
>     >
>     > i 'am asking if it's possible to override core class by inclusion
>     >
>     > i mean something like this :
>     > ----------------------------------------------------
>     >
>     > #file /mypath/view.lzx
>     >
>     > <class name="view">
>     >
>     > // my own view class
>     >
>     > </class>
>     >
>     >
>     > and later...
>     >
>     > #file /myotherpath/myapp.lzx
>     >
>     > <include href="/mypath/view.lzx"/>
>     >
>     > <canvas>
>     >
>     > <!-- use of the overrided class -->
>     >    <view name="lalala" />
>     >
>     > </canvas>
>     >
>     > ----------------------------------------------------
>     >
>     > I've tried with "view" and "text" as class name     ==>     does
>     > not work (compilation error)
>     > then i've tried with "menu" or "button"                 ==>     it
>     > work althought i get a warning message in debug console
>     >
>     > i guess it's because view and text are in the LFC, but menu and
>     > button are component ...
>     >
>     > but my question is:
>     >
>     > except for LFC that sems impossible to override, for the other
>     > class, is this allowed ?? will cause problem ???
>     >
>     >
>     > thanks
>     >
>     > Pierre
>     >
>     >
>
>
>
>
> -- 
> Henry Minsky
> Software Architect
> hminsky at laszlosystems.com <mailto:hminsky at laszlosystems.com>
>