> Hi Didier,
>
Hi Andreas,
> what I showed you in the last snippet is exactly what happens in
> OpenLayers.Class. So to do it the way we recommend, and if you're into
> anonymous functions, you could do something like the following, which is
> 100% OpenLayers API compliant:
>
> var X = OpenLayers.Class({
> initialize: function() {
> this._p = "A.initialize";
> OpenLayers.Console.info(this._p);
> },
> ma: function() {
> OpenLayers.Console.info(this._p);
> }
> });
> var x1 = new (OpenLayers.Class(X, {
> initialize: function() {
> this._p = "A.initialize-new";
> OpenLayers.Console.info(this.p_);
> }
> }));
>
I have tested something like this for my use case :
A= OpenLayers.Class({...});
A.B= OpenLayers.Class(A, {...});
A= OpenLayers.Class(A, { ...});
var a= new A(); //ok
var ab= new AB(); //ko: A.B is not a constructor ...
My idea was just to overwrite part of a class path and have it propagated ...
I have this working in OL 2.10 (based on your snippet):
/**
* Function: OpenLayers.overload
* Apply the patch to the given class and propagate it downward
* to the sub-classes by insuring that only not overwritten
* methods() or properties are overloaded.
*
* Parameters:
* P - {Object} an instance of {<OpenLayers.Class>}
* F - {Object} an object used to overwrite methods (including
* constructor) and properties of P and its sub-classes.
*
* Returns:
* {Object} the overloaded instance of given class.
*/
OpenLayers.overload= function(P,F) {
//save old class
var X= P;
var xProto= OpenLayers.Util.extend({},P.prototype);
var f= OpenLayers.Util.extend({},F);
if (typeof(F.initialize)=="function") {
// protect initializer from sub-classes overloading :
var pProto= P.prototype;
pProto.initialize= function() {
F.initialize.apply(this,arguments); };
delete f["initialize"];
OpenLayers.Util.extend(pProto,f);
P= pProto.initialize;
P.prototype= pProto;
} else {
OpenLayers.Util.extend(P.prototype, f);
}
// restore sub-classes:
// propagate constructor/properties/method to sub-class ...
for (var xn in X) {
var p= X[xn];
delete X[xn];
if (typeof(p)=='function' && p.prototype.initialize) {//ensure
it is a Class
f= OpenLayers.Util.extend({},F);
// check for overloaded properties :
for (var fn in F) {
var fp= F[fn];
if (typeof(fp)=="function") {
if (p.prototype[fn]===xProto[fn]) {
// override method ...
continue;
}
delete f[fn];
continue;
}
if (p.prototype.hasOwnProperty(fn) &&
X.prototype.hasOwnProperty(fn) && fp!==undefined) {
if (p.prototype[fn]===xProto[fn]) {
// override property ...
continue;
}
delete f[fn];
continue;
}
}
// override sub-class :
var x= p;
var c= OpenLayers.Class(P,p.prototype);
OpenLayers.Util.extend(c,x);
P[xn]= OpenLayers.overload(c,f);
} else {
P[xn]= p;
}
}
xProto= null;
X= null;
return P;
};
The classes tree is the one I sent yesterday:
A= OpenLayers.Class({
initialize:function() { this.p_= "A.initialize";
OpenLayers.Console.info(this.p_); },
pa:"PA",
p_:null,
ma:function() { OpenLayers.Console.info("A.ma="+this.pa); }
});
A.B= OpenLayers.Class(A,{
pa:"PA-bis",
pb:"PB",
mb:function() { OpenLayers.Console.info("B.mb="+this.pa+"
"+this.pb); }
});
A.B.D= OpenLayers.Class(A.B,{
initialize:function() { this.p_= "D.initialize";
OpenLayers.Console.info(this.p_); }
});
A.B.E= OpenLayers.Class(A.B,{
initialize:function() { this.p_= "E.initialize";
OpenLayers.Console.info(this.p_); }
});
A.C= OpenLayers.Class(A,{
initialize:function() { this.p_= "C.initialize";
OpenLayers.Console.info(this.p_); },
pc:"PC",
ma:function() { OpenLayers.Console.info("C.ma="+this.pa+"
"+this.pc); }
});
A.C.F= OpenLayers.Class(A.C,{
pf:"PF",
mf:function() { OpenLayers.Console.info("F.mf="+this.pa+"
"+this.pc+" "+this.pf); }
});
A.C.G= OpenLayers.Class(A.C,{
pg:"PG",
ma:function() { OpenLayers.Console.info("G.ma="+this.pa+"
"+this.pc+" "+this.pg); }
});
and then :
A= OpenLayers.overload(A, {
initialize:function() { this.p_= "A.initialize-new";
OpenLayers.Console.info(this.p_); },
pa:"PA-new"
});
to overload the classes tree ...
The same method "almost works" in OL 2.11 except that in the end, I have
got all sub-classes in the root, and so on recursively :
A
B
B
C
D
E
C
F
F
G
G
D
E
(again, in OL 2.10, everything looks good in the end)
I may be in the wrong path to solve my problem ...
Any thoughts ?
> Andreas.
didier
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