$(document).ready(function() {
    appendCountries();
    $('#form_country').change(function() {
        appendStates();
    });
    $('#form_state').change(function() {
        appendCity();
    });
    $('.btn').click(function() {
        AddListItem();
    });
});
 
function appendCountries() {
    $.ajax({
        url: "../_vti_bin/ListData.svc/CountryStateCity()?$orderby= Title asc&$select=Title",
        type: "get",
        headers: {
            "Accept": "application/json;odata=verbose"
        },
        success: function(data) {
            var values = [];
            var uniqueValues = [];
            var option = "";
            var valuesArray = data.d.results;
            $.each(valuesArray, function(i, result) {
                values.push(result.Title);
            });
            $.each(values, function(i, el) {
                if ($.inArray(el, uniqueValues) === -1) {
                    uniqueValues.push(el);
                    option += "<option value="" + el + "">" + el + "</option>";
                }
            });
            $("#form_country").append(option);
        },
        error: function(data) {
            alert(data.responseJSON.error);
        }
    });
}
 
function appendStates() {
    var country = $('#form_country').val();
    $.ajax({
        url: "../_vti_bin/ListData.svc/CountryStateCity()?$select=State&$filter=Title eq '" + country + "'&$expand=State&$orderby= State/Title asc",
        type: "get",
        headers: {
            "Accept": "application/json;odata=verbose"
        },
        success: function(data) {
            var values = [];
            var uniqueValues = [];
            var option = "";
            var valuesArray = data.d.results;
            $.each(valuesArray, function(i, result) {
                values.push(result.State.Title);
            });
            $.each(values, function(i, el) {
                if ($.inArray(el, uniqueValues) === -1) {
                    uniqueValues.push(el);
                    option += "<option value="" + el + "">" + el + "</option>";
                }
            });
            $("#form_state").empty();
            $("#form_state").append(option);
        },
        error: function(data) {
            alert(data.responseJSON.error);
        }
    });
}
 
function appendCity() {
    var state = $('#form_state').val();
    $.ajax({
        url: "../_vti_bin/ListData.svc/CountryStateCity()?$select=City&$filter=State/Title eq '" + state + "'&$expand=State,City&$orderby= City/Title asc",
        type: "get",
        headers: {
            "Accept": "application/json;odata=verbose"
        },
        success: function(data) {
            var values = [];
            var uniqueValues = [];
            var option = "";
            var valuesArray = data.d.results;
            $.each(valuesArray, function(i, result) {
                values.push(result.City.Title);
            });
            $.each(values, function(i, el) {
                if ($.inArray(el, uniqueValues) === -1) {
                    uniqueValues.push(el);
                    option += "<option value="" + el + "">" + el + "</option>";
                }
            });
            $("#form_city").empty();
            $("#form_city").append(option);
        },
        error: function(data) {
            alert(data.responseJSON.error);
        }
    });
}
 
function AddListItem()
{
    var firstName = $("#form_name").val();
    var lastName = $("#form_lastname").val();
    var email = $("#form_email");
    var phone = $('#form_phone');
    var country = $('#form_country');
    var state = $('#form_state');
    var city = $('#form_city');
    var address = $('#form_address');
    $.ajax({
        url: _spPageContextInfo.webAbsoluteUrl + "../_vti_bin/ListData.svc/EmployeeDetails()",
        type: "POST",
        data: JSON.stringify({
            __metadata:
            {
                type: "SP.Data.TestListItem"
            },
            FirstName: firstName,
            Lastname: lastName,
            Email: email,
            Phone: phone,
            Country: country,
            State: state,
            City: city,
            Address: address
        }),
        headers:
        {
            "Accept": "application/json;odata=verbose",
            "Content-Type": "application/json;odata=verbose",
            "X-RequestDigest": $("#__REQUESTDIGEST").val(),
            "X-HTTP-Method": "POST"
        },
        success: function(data, status, xhr)
        {
            alert('Request has been submitted successfully');
        },
        error: function(xhr, status, error)
        {
            
//console.log(data.responseJSON.error);
            alert('Error');
        }
    });
}