Bryntum Support Forums

import Override from 'Core/mixin/Override.js';
Override.apply(class {
  static get target() {
    return { class : AggregateColumn }
  }

  getRawValue(record) {
    let value = 0;

    if (record.children) {
        const
            me       = this,
            fn       = me.function,
            isMathFn = typeof fn === 'string' && typeof Math[fn] === 'function',
            {
                handler,
                thisObj
            } = isMathFn ? {
                handler : Math[fn],
                thisObj : Math
            } : me.resolveCallback(fn);

        for (let i = 0, { length } = record.children; i < length; i++) {
            value = handler.call(thisObj, value, me.getRawValue(record.children[i]));
        }
        record[me.field] = value;
    }
    else {
        value = record[this.field];
    }
    return value;
  }
})