Reading JSON data from Google Geocoding API with jQuery

问题

I am trying to learn about Google Maps Geocoding and how to read the JSON data it sends back. This is what Google sends back:

{
   "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"
}

I get this response with this code:

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

The problem is I don't know what to put inside processJSON. I was reading the tutorial here: https://www.sitepoint.com/ajaxjquery-getjson-simple-example/ and the documentation on .getJSON() on http://api.jquery.com/jquery.getjson/. However, I'm having trouble understanding both sites.

If I wanted to get the postal_code, how would I do read the data? I tried this:

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

I tried it with getJSON() as well after success:

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

However, neither alert anything. What am I doing wrong? Thanks in advance!

回答1:

add success function after youu ajax

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

回答2:

You would need to parse the data on your success function.

function processJSON(data) {
    var json = JSON.parse(data);
   //..
}

Also add an error function to your $.ajax as well

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

来源：https://stackoverflow.com/questions/38669434/reading-json-data-from-google-geocoding-api-with-jquery