Extend a Ext.data.Store and change some Parameters

[testmacher]

Hello,

I have 8 stores like this in my App:

HR.stores.ConfigStore = new Ext.data.Store({
    autoLoad : false,
    model : 'Config',
    proxy: {
        type: 'scripttag',
        url: 'xxx.php',
        callbackKey: 'callback',
        extraParams: {
            method : 'config'
        },
        reader: {
            type: 'json',
            root: 'results'
        }
    }
}); 

The only thing that makes the difference in these stores are the models an extraParams of the proxy.

Is it impossible to create a MainStore like this

HR.stores.MainStore = new Ext.data.Store({
    autoLoad : false,
    proxy: {
        type: 'scripttag',
        url: 'xxx.php',
        callbackKey: 'callback',
        reader: {
            type: 'json',
            root: 'results'
        }
    }
}); 

and then extend this store several times and applying the mentioned differences?

I already tried some things I found here:

HR.stores.ConfigStore = Ext.extend(HR.stores.MainStore, {
    constructor:function (config) {
        config = config || {};

        Ext.applyIf(config, {
            model:'Config',
            proxy:{
                extraParams:{
                    method:'config'
                }
            }
        });

        HR.stores.ConfigStore.superclass.constructor.call(this, config);
    }
}); 

But I get errors like "Cannot read property 'proxy' of undefined"...

How has the extended store to look like?

Regards,

testmacher

[mitchellsimoens]

MainStore = Ext.extend(Ext.data.Store, {
    constructor : function(config) {
        config = config || {};

        var extraParams = config.extraParams || this.extraParams;

        Ext.applyIf(config, {
            model : 'Config',
            proxy : {
                extraParams : extraParams
            }
        });

        MainStore.superclass.constructor.call(this, config);
    }
});

UserStore = Ext.extend(MainStore, {
    constructor : function(config) {
        this.extraParams = {
            foo : 'bar'
        };

        UserStore.superclass.constructor.call(this, config);
    }
});

[testmacher]

Hello,

thanks for the answer, but one problem remains if I do like this.
I get:

Uncaught TypeError: Object function (config) {
        this.extraParams = {
            foo : 'bar'
        };
        ConfigStore.superclass.constructor.call(this, config);
    } has no method 'load' 

if I try to 'load' the store (the ConfigStore).

I also register like that:

Ext.regStore('app_configStore', ConfigStore); 

What do I have to change there? Must the MainStore also be registered?

Regards,

testmacher

[testmacher]

anyone?