在Extjs中动态扩展类

Question

I need to extend class dynamically and use this code:

Calc.grid.Table["Table"+key] = function(config) {
        config = config || {};
        Ext.applyIf(config,{
                id: 'calc-grid-table'+key
                ,baseParams: { 
                    action: 'mgr/calc/calcGetTable'+key
                    ,query: 'Calc'+key 
                }
        });
        Calc.grid.Table["Table"+key].superclass.constructor.call(this,config)
};
Ext.extend(Calc.grid.Table["Table"+key],Calc.grid.Table);
Ext.reg('calc-grid-table'+key,Calc.grid.Table["Table"+key]);

but it gives me an error:

Uncaught TypeError: Cannot read property 'superclass' of undefined

I tried to change it to this

this.superclass.constructor.call(this,config)

but error is

Uncaught SyntaxError: Unexpected identifier

The problem is in dynamic literals. When I do like this it works fine

Calc.grid.Table.Table21 = function(config) {
        config = config || {};
        Ext.applyIf(config,{
                id: 'calc-grid-table'+21
                ,baseParams: { 
                    action: 'mgr/calc/calcGetTable'+21
                    ,query: 'Calc'+21
                }
        });
        Calc.grid.Table.Table21.superclass.constructor.call(this,config)
};
Ext.extend(Calc.grid.Table.Table21,Calc.grid.Table);
Ext.reg('calc-grid-table'+21,Calc.grid.Table.Table21);

How can I fix it? What am I doing wrong?

Thanx in advance.

Answer 1

You're key variable being used in your constructor isn't scoped to that function, so it is possible that is can be changed before the constructor is called. You can use Ext's createDelegate to tie the variable to the function so that it can't change on you:

Calc.grid.Table["Table"+key] = function(key, config) {
    config = config || {};
    Ext.applyIf(config,{
            id: 'calc-grid-table'+key
            ,baseParams: { 
                action: 'mgr/calc/calcGetTable'+key
                ,query: 'Calc'+key 
            }
    });
    Calc.grid.Table["Table"+key].superclass.constructor.call(this,config)
}.createDelegate(this, [key], 0);