预测未定义的结果条件

Question

我编辑了一些jquery天气代码，当我添加一些响应字段时，并非所有字段都清楚结果，我有未定义的结果条件。

示例:Max。温度:42℃/108F最低温度:27℃/80F风:未定义

$(function() { var handlers = {
simplePrint : function (location){
  var new_location_div = $('<div>');
  new_location_div.addClass('location');
  new_location_div.data('l',location.l);
  new_location_div.data('city',location.name);
  var location_p = $('<p>').text(location.name)
  new_location_div.append(location_p);
  $('#search_result').append(new_location_div);
},
displayPrint : function (location,day){
  var display = $('<div>');
  display.addClass('display_on')
  location =  $('<p>').text('Location: ' + location);
  high_temp = $('<p>').text('Max. temp: ' + day.high.celsius + 'C / ' + day.high.fahrenheit + 'F');
  min_temp = $('<p>').text('Min. temp: ' + day.low.celsius + 'C / ' + day.low.fahrenheit + 'F');
  wind_dir = $('<p>').text(' ' + day.wind_dir +' ');
  display.append(location,high_temp,min_temp,wind_dir);
  // "Thunderstorm" "Chance of Rain" "Overcast" "Partly Cloudy" "Rain" "Clear"
  $('#display_today').slideUp('slow');
  var condition = ['clear', 'sunny'].indexOf(day.conditions.toLowerCase())
  if (condition === -1 ) { 
   $('body').fadeTo('slow', 0, function()
    { 
      $(this).css('background-image', 'url("http://harrymoroz.com/wp-content/uploads/2014/04/1_See_It.jpg")');
    }).fadeTo('slow', 1);
   $('h1').css({'color': 'white'});
   $('.starter-template > p').css({'color': 'white'});
  }else{
    $('body').fadeTo('slow', 0, function()
    { 
      $(this).css('background-image', 'url("https://melodywren.files.wordpress.com/2011/04/p1040585.jpg")');
    }).fadeTo('slow', 1);
   $('h1').css({'color': 'rgb(#333)'});
   $('p').css({'color': 'rgb(#333)'});
  };
  setTimeout(function(){
    $('.display_on').remove();
    $('#display_today').append(display);
    $('#display_today').slideDown('400');
  }, '800'); } } $('#search_form_submit').on('click keypress',  function(event) {
event.preventDefault();
var search_query = $('#search_field').val();
if (!search_query) {
  $('.location').remove();
  return;
};  
$.ajax({
  url: 'http://autocomplete.wunderground.com/aq?query=' + search_query ,
  type: 'GET',
  dataType: 'jsonp',
  jsonp: 'cb', 
  })
    .done(function(search_api_answer) {
    $('.location').remove();  
  search_api_answer.RESULTS.filter(function(location){
     return location.type === 'city'
  }).forEach(handlers.simplePrint);
});
$('#search_form').trigger("reset");
    });$('#search_result').on('click', '.location', function(event) {
event.preventDefault();
var selected_location = $(this)
var lCode = selected_location.data('l');
$.ajax({
  url: 'http://api.wunderground.com/api/0ce1c4a981f7dd2a/conditions/forecast/q/'+ lCode + '.json',
  type: 'GET',
  dataType: 'json',
  // jsonp: 'cb',
})
.done(function(api_city_forecast,conditions) {
  todayForecast = api_city_forecast.forecast.simpleforecast.forecastday[0];
  cityForecast = selected_location.data('city');
  conditions = conditions.current_observation;
  handlers.displayPrint(cityForecast,todayForecast,conditions);});});});

Answer 1

查看结果

http://api.wunderground.com/api/0ce1c4a981f7dd2a/conditions/forecast/q/kzn.json

似乎有些项目，如"day"变量，可能并不总是像你期望的那样填写。具体来说，JSON响应中的"day"变量没有"high"或"low"属性——它只有一个值。

你可能想让你的应用迎合这种情况，即当weatherunderground不知道查询的所有值，但提供一个基本值。