[Laszlo-user] Appreciation for OL and an important code snippet to share for christmas

[James Robey]

I just wanted to take the time out of a busy coding schedule to tell  
the list (and all of the people subscribed but not active posters)  
just how much i like, appreciate, and use the Open Laszlo framework  
day to day. It is a joy to use, a joy to discuss, and a pleasure to  
earn a living with. Thank you, all that have ever been involved, in  
producing something of such abstractional purity, of such clarity and  
ease, that it has changed and refocused my coding life.

Thanks to all of You, who make this open-source project the success it  
is.

Sincerely,
	James Robey.

p.s. i am releasing, for those in the know and not afraid to ponder a  
short code segment, something called "waypoints" for the OL language.  
It allows you to manipulate/access deeply nested view hierarchies with  
NONE of the usual headaches. I hope that this will be of use to the  
whole community. The extremely short code and explanation is attached  
as a text file. To me, it is a addition and celebration of the magic  
we have to play with here, and of constant utility to my everyday  
work. Thanks for reading and Merry Christmas!

(waypoints.lzx attached and reproduced below)

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<canvas width="500" height="500" bgcolor="yellow">

   <!-- The waypoint class allows for "deep" navigation of nested  
namespaces -->
   <class name="waypoint" extends="node" initstage="early">
     <!-- if this atttribute is specified, then the waypoint will be  
added at that node -->
     <attribute name="at" type="expression"/>

     <!-- if this attribute is specified, then a waypoint by this name  
will be added to the waypoint parent -->
     <attribute name="named" type="string"/>

     <!-- at construct time, determine the waypoint parent and add  
references, as/if needed -->
     <method name="construct" args="p, a">
       //retrieve values from the tag
       var at = a['at'];
       var named = a['named']
       var np = at ? eval(at) : p.parent;

       //find out which node will receive the new waypoint
       while(1){

           //have we found a potential parent waypoint or have an "at"  
operation (waypoint explicitly on)?
           if(at || np['_'] || np['id'] || np.nodeLevel == 0){

               //initialize space ('_') to hold waypoints if this is a  
new waypoint parent.
               if(np['_'] == undefined) np._ = {};

               //if no name given make a name based on the number of  
other nameless waypoints
               //otherwise ensure the name doesn't overwrite anything  
in the target waypoint space.
               if(!named){
                   // if __waypointCount is not defined initialize it  
to zero, otherwise increment
                   np.__waypointcount = np['__waypointcount'] !=  
undefined ? np.__waypointcount + 1 : 0;

                   // and use value that to generate a unique name
                   named = "__waypoint"+np.__waypointcount;
               }else if(np._[named] != undefined){
                   Debug.warn('waypoint overwritten:', np, 'name',  
named);
               }

               //Add this node to a waypoint parent, add the waypoint  
to this node ("parent"), then break
               np._[named] = p;

               if(!p['_'])
                 p._ = new Object;

               //record the parent waypoint to this tag
               p._.parent = np;
               break;
           }

           //...or just keep looking up the tree until we find a good  
target.
           np = np.parent;
       }

       //we don't need the this anymore, it's done it's job (cyclic  
GC? investigate)
       super.construct();
     </method>
   </class>

   <!-- test of the waypoint utility. Note that we can set the  
innermost color in the init handler
        regardless of how many enclosing <view>'s the tag is in! No  
'useless' names to change when you wrap
        a view to get some visual effect or another. No globals!
   -->

   <simplelayout axis="y"/>

   <view name="topview">
     <waypoint/>
     <view width="100" height="100" bgcolor="blue">
         <view width="50" height="50" bgcolor="green">
             <view width="25" height="25" bgcolor="red">
                 <waypoint named="test"/>
             </view>
         </view>
     </view>
   </view>

   <view width="100" height="100" bgcolor="black">
     <text fgcolor="white" text="click me"/>
     <handler name="onclick">
       canvas.topview._.test.setAttribute('bgcolor', '0xffffff');
     </handler>
   </view>

</canvas>