Tea.context(function () { this.letterGroups = [ "ABC", "DEF", "GHI", "JKL", "MNO", "PQR", "STU", "VWX", "YZ" ]; this.selectedGroup = "ABC" this.letterCountries = {} let that = this this.countries.forEach(function (country) { if (typeof (that.letterCountries[country.letter]) == "undefined") { that.letterCountries[country.letter] = [] } that.letterCountries[country.letter].push(country) }) this.isCheckingAll = false this.selectGroup = function (group) { this.selectedGroup = group } this.success = NotifyPopup })