使用jQuery

Question

我正在尝试了解Google地图地理编码以及如何读取它发回的JSON数据。这就是Google发回的内容：

{
   "results" : [
      {
         "address_components" : [
            {
               "long_name" : "1600",
               "short_name" : "1600",
               "types" : [ "street_number" ]
            },
            {
               "long_name" : "Amphitheatre Pkwy",
               "short_name" : "Amphitheatre Pkwy",
               "types" : [ "route" ]
            },
            {
               "long_name" : "Mountain View",
               "short_name" : "Mountain View",
               "types" : [ "locality", "political" ]
            },
            {
               "long_name" : "Santa Clara County",
               "short_name" : "Santa Clara County",
               "types" : [ "administrative_area_level_2", "political" ]
            },
            {
               "long_name" : "California",
               "short_name" : "CA",
               "types" : [ "administrative_area_level_1", "political" ]
            },
            {
               "long_name" : "United States",
               "short_name" : "US",
               "types" : [ "country", "political" ]
            },
            {
               "long_name" : "94043",
               "short_name" : "94043",
               "types" : [ "postal_code" ]
            }
         ],
         "formatted_address" : "1600 Amphitheatre Parkway, Mountain View, CA 94043, USA",
         "geometry" : {
            "location" : {
               "lat" : 37.4224764,
               "lng" : -122.0842499
            },
            "location_type" : "ROOFTOP",
            "viewport" : {
               "northeast" : {
                  "lat" : 37.4238253802915,
                  "lng" : -122.0829009197085
               },
               "southwest" : {
                  "lat" : 37.4211274197085,
                  "lng" : -122.0855988802915
               }
            }
         },
         "place_id" : "ChIJ2eUgeAK6j4ARbn5u_wAGqWA",
         "types" : [ "street_address" ]
      }
   ],
   "status" : "OK"
}

我用这段代码得到了这个回复：

$("#submit").click(function(event) {
  var address = encodeURIComponent($("#location").val());

  $.ajax({
    type: "GET",
    url: "https://maps.googleapis.com/maps/api/geocode/json?address=" + address + "&sensor=false&key=" + API_KEY,
    dataType: "json",
    success: processJSON
  });

  function processJSON(json) {
    // Do stuff here
  }
});

问题是我不知道在processJSON内放什么。我在这里阅读教程：https://www.sitepoint.com/ajaxjquery-getjson-simple-example/以及http://api.jquery.com/jquery.getjson/上.getJSON()上的文档。但是，我无法理解这两个网站。

如果我想获得postal_code，我该如何阅读数据？我试过这个：

function processJSON(json) {
    // Do stuff here
    alert("Postal Code:" + json.address_components[6].long_name);
  }

我在getJSON()之后使用success尝试了它：

$.getJSON(url, function(json) {
  alert("Postal Code:" + json.address_components[6].long_name);
 });

然而，既不提醒任何事情。我究竟做错了什么？提前谢谢！

Answer 1

在youu ajax之后添加成功函数

$("#submit").click(function(event) {
  var address = encodeURIComponent($("#location").val());

  $.ajax({
    type: "GET",
    url: "https://maps.googleapis.com/maps/api/geocode/json?address=" + address + "&sensor=false&key=" + API_KEY,
    dataType: "json",
    success: processJSON
  }).success(function(data){
    processJSON(data);
  }

  function processJSON(json) {
    // Do stuff here
    console.log(json);
    alert("Postal Code:" + json.results[0].address_components[6].long_name);
  }
});

Answer 2

您需要解析成功函数的数据。

$.ajax({ 
    type..
    url...
    success..
    error: function() {
        console.log('error on request')
    }
    ...

还要在$ .ajax中添加错误功能

fill :: Traversable t => t (Maybe a) -> [a] -> Maybe (t a)
fill = evalStateT . traverse foo where
  foo x = maybe empty pure x <|> StateT uncons