Question

Hi as the Title says i am getting this error suddenly without changing anything.
This is the File Locations Code:

Ext.define('Wickelplaetze.store.Locations', {
extend: 'Ext.data.Store',
requires: 'Wickelplaetze.model.Location',

config: {
    model: 'Wickelplaetze.model.Location',
    storeId: 'locationsstore',
    grouper: {
        groupFn: function(record) {
            return record.get('ort').substr(0, 1);
        },
        sortProperty: 'ort'
    },
    proxy: {
        type: 'ajax',
        url: 'http://freakp.com/wpapp/form-data.json',
        withCredentials: false,
        useDefaultXhrHeader: false
    },
    autoLoad: true
}   

});

Answer 1

There are null values in you json for key ort. You can check if ort is not null and then return like –

 if(record.get("ort")!= null){
     return record.get('ort')[0];
 }

Will remove that error doing so. But this will not sort records properly.

One more thing, if you want to sort list by first letter of ort , you can directly use –

return record.get("ort")[0];

When I tried your code to populate list, its actually running infinitely. I didn’t get anything. Sorting these much values is damn slow. It took 3 mins to populate the list.

UPDATE

Link for working fiddle for your example. You can see null values at bottom of list. There are 7 null values for key ort.