Handle Results of Multiple AJAX Requests with jQuery Promises

gistfile1.txt

function getReq(req, reqType) {
    var fy1req = req + '/year/' + perDiemSearch.startFY;

    function getStartFY() {

        return $.ajax({
                url: fy1req,
            }).done(function(data) {
                //no rates
                if (!data.rates || data.rates.length === 0) {
                    //if search has state, search again for state
                    if (reqType === 'city-state') {
                        //build a new request, ignore city
                        buildReq(true);
                    } else {
                        //else error
                        locationError()
                    }
                    reqError = true;
                } else {
                    reqError = false;
                    var rates = data.rates[0].rate;
                    if (rates.length > 1) {
                        //multiple rates are available for FY1
                        for (i in rates) {
                            if (rates[i].county === ' ') {
                                rates[i].county = 'Standard Rate'
                            }
                        }
                        perDiemSearch.rates.fy1 = {
                            year: perDiemSearch.startFY,
                            multiple: true,
                            rates: rates
                        }

                    } else {

                        perDiemSearch.rates.fy1 = {
                            year: perDiemSearch.startFY,
                            multiple: false,
                            rate: rates[0]
                        }
                    }
                }
            })
            .fail(function() {

                $('#perdiem-multiple-rates-check').html('Next')
                reqError = true;
                $('#perdiem-api-error').show()
            })
    }

    //if search includes 2 fiscal years
    function getEndFY() {
        if (perDiemSearch.startFY !== perDiemSearch.endFY) {

            var fy2req = req + '/year/' + perDiemSearch.endFY;
            return $.ajax({
                    url: fy2req,
                }).done(function(data) {
                    //data = JSON.parse(data)
                    if (!data.rates || data.rates.length === 0) {
                        //if search has state, search again for state
                        if (reqType === 'city-state') {
                            //build a new request, ignore city
                            buildReq(true);
                        } else {
                            //else error
                            locationError()
                        }
                        reqError = true;
                    } else {
                        reqError = false;
                        var rates = data.rates[0].rate;
                        if (rates.length > 1) {
                            for (i in rates) {
                                if (rates[i].county === ' ') {
                                    rates[i].county = 'Standard Rate'
                                }
                            }
                            perDiemSearch.rates.fy2 = {
                                year: perDiemSearch.endFY,
                                multiple: true,
                                rates: rates
                            }

                        } else {

                            perDiemSearch.rates.fy2 = {
                                year: perDiemSearch.endFY,
                                multiple: false,
                                rate: rates[0]
                            }
                        }
                    }
                })
                .fail(function() {

                    $('#perdiem-multiple-rates-check').html('Next')
                    $('#perdiem-api-error').show()
                    reqError = true;
                })
        } else {
            return true
        }
    }



    $.when(getStartFY(), getEndFY()).done(function() {
        if (reqError === true) {

        } else {

            //if multiple rates available, show multiple rates UI

            if (perDiemSearch.rates.fy2) {
                if (perDiemSearch.rates.fy1.multiple || perDiemSearch.rates.fy2.multiple) {
                    displayRates()
                } else {
                    calculateRates()
                }
            } else {
                if (perDiemSearch.rates.fy1.multiple) {
                    displayRates()
                } else {
                    calculateRates()
                }
            }
        }
    });
}