Google API：计算位置结果

Question

我想看看我可以对搜索附近餐馆的 API 进行哪些改进。我想做的是创建一个文本显示来告诉用户找到了多少个位置，但我没有找到任何可以用作参考点的东西来说明如何做到这一点。有没有办法将位置搜索的搜索结果转换为总数？我假设我需要某种计数器，但我不确定。作为参考，这里是原始代码。

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>Place search pagination</title>
    <style>
      /* Always set the map height explicitly to define the size of the div
       * element that contains the map. */
      #map {
        height: 100%;
      }
      /* Optional: Makes the sample page fill the window. */
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
      #right-panel {
        font-family: 'Roboto','sans-serif';
        line-height: 30px;
        padding-left: 10px;
      }

      #right-panel select, #right-panel input {
        font-size: 15px;
      }

      #right-panel select {
        width: 100%;
      }

      #right-panel i {
        font-size: 12px;
      }
      #right-panel {
        font-family: Arial, Helvetica, sans-serif;
        position: absolute;
        right: 5px;
        top: 60%;
        margin-top: -195px;
        height: 330px;
        width: 200px;
        padding: 5px;
        z-index: 5;
        border: 1px solid #999;
        background: #fff;
      }
      h2 {
        font-size: 22px;
        margin: 0 0 5px 0;
      }
      ul {
        list-style-type: none;
        padding: 0;
        margin: 0;
        height: 271px;
        width: 200px;
        overflow-y: scroll;
      }
      li {
        background-color: #f1f1f1;
        padding: 10px;
        text-overflow: ellipsis;
        white-space: nowrap;
        overflow: hidden;
      }
      li:nth-child(odd) {
        background-color: #fcfcfc;
      }
      #more {
        width: 100%;
        margin: 5px 0 0 0;
      }
    </style>
    <script>
      // This example requires the Places library. Include the libraries=places
      // parameter when you first load the API. For example:
      // <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=places">

      var map;

      function initMap() {
        // Create the map.
        var pyrmont = {lat: -33.866, lng: 151.196};
        map = new google.maps.Map(document.getElementById('map'), {
          center: pyrmont,
          zoom: 17
        });

        // Create the places service.
        var service = new google.maps.places.PlacesService(map);
        var getNextPage = null;
        var moreButton = document.getElementById('more');
        moreButton.onclick = function() {
          moreButton.disabled = true;
          if (getNextPage) getNextPage();
        };

        // Perform a nearby search.
        service.nearbySearch(
            {location: pyrmont, radius: 500, type: ['restaurants']},
            function(results, status, pagination) {
              if (status !== 'OK') return;

              createMarkers(results);
              moreButton.disabled = !pagination.hasNextPage;
              getNextPage = pagination.hasNextPage && function() {
                pagination.nextPage();
              };
            });
      }

      function createMarkers(places) {
        var bounds = new google.maps.LatLngBounds();
        var placesList = document.getElementById('places');

        for (var i = 0, place; place = places[i]; i++) {
          var image = {
            url: place.icon,
            size: new google.maps.Size(71, 71),
            origin: new google.maps.Point(0, 0),
            anchor: new google.maps.Point(17, 34),
            scaledSize: new google.maps.Size(25, 25)
          };

          var marker = new google.maps.Marker({
            map: map,

            title: place.name,
            position: place.geometry.location
          });

          var li = document.createElement('li');
          li.textContent = place.name;
          placesList.appendChild(li);

          bounds.extend(place.geometry.location);
        }
        map.fitBounds(bounds);
      }
    </script>
  </head>
  <body>
    <div id="map"></div>
    <div id="right-panel">
      <h2>Results</h2>
      <ul id="places"></ul>
      <button id="more">More results</button>
    </div>
    <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBYoCkx3owRBY3uLwBvW36B0GNeMQtBm1o&libraries=places&callback=initMap" async defer></script>
  </body>
</html>

Answer 1

使用长度最简单placesList.children。添加放置数字的位置：

<div id="right-panel">
  <h2>Results</h2>
  <div id="number_results"></div>
  <ul id="places"></ul>
  <button id="more">More results</button>
</div>

然后在javascript中，把placesList.children.length放在那里：

var li = document.createElement('li');
li.textContent = place.name;
placesList.appendChild(li);
document.getElementById('number_results').innerHTML = placesList.children.length+" returned";

代码片段：

// This example requires the Places library. Include the libraries=places
// parameter when you first load the API. For example:
// <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=places">

var map;

function initMap() {
  // Create the map.
  var pyrmont = {
    lat: -33.866,
    lng: 151.196
  };
  map = new google.maps.Map(document.getElementById('map'), {
    center: pyrmont,
    zoom: 17
  });

  // Create the places service.
  var service = new google.maps.places.PlacesService(map);
  var getNextPage = null;
  var moreButton = document.getElementById('more');
  moreButton.onclick = function() {
    moreButton.disabled = true;
    if (getNextPage) getNextPage();
  };

  // Perform a nearby search.
  service.nearbySearch({
      location: pyrmont,
      radius: 500,
      type: ['restaurants']
    },
    function(results, status, pagination) {
      if (status !== 'OK') return;

      createMarkers(results);
      moreButton.disabled = !pagination.hasNextPage;
      getNextPage = pagination.hasNextPage && function() {
        pagination.nextPage();
      };
    });
}

function createMarkers(places) {
  var bounds = new google.maps.LatLngBounds();
  var placesList = document.getElementById('places');

  for (var i = 0, place; place = places[i]; i++) {
    var image = {
      url: place.icon,
      size: new google.maps.Size(71, 71),
      origin: new google.maps.Point(0, 0),
      anchor: new google.maps.Point(17, 34),
      scaledSize: new google.maps.Size(25, 25)
    };

    var marker = new google.maps.Marker({
      map: map,
      title: place.name,
      position: place.geometry.location
    });

    var li = document.createElement('li');
    li.textContent = place.name;
    placesList.appendChild(li);
    document.getElementById('number_results').innerHTML = placesList.children.length + " returned";

    bounds.extend(place.geometry.location);
  }
  map.fitBounds(bounds);
}

/* Always set the map height explicitly to define the size of the div
       * element that contains the map. */

#map {
  height: 100%;
}


/* Optional: Makes the sample page fill the window. */

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#right-panel {
  font-family: 'Roboto', 'sans-serif';
  line-height: 30px;
  padding-left: 10px;
}

#right-panel select,
#right-panel input {
  font-size: 15px;
}

#right-panel select {
  width: 100%;
}

#right-panel i {
  font-size: 12px;
}

#right-panel {
  font-family: Arial, Helvetica, sans-serif;
  position: absolute;
  right: 5px;
  top: 60%;
  margin-top: -195px;
  height: 330px;
  width: 200px;
  padding: 5px;
  z-index: 5;
  border: 1px solid #999;
  background: #fff;
}

h2 {
  font-size: 22px;
  margin: 0 0 5px 0;
}

ul {
  list-style-type: none;
  padding: 0;
  margin: 0;
  height: 271px;
  width: 200px;
  overflow-y: scroll;
}

li {
  background-color: #f1f1f1;
  padding: 10px;
  text-overflow: ellipsis;
  white-space: nowrap;
  overflow: hidden;
}

li:nth-child(odd) {
  background-color: #fcfcfc;
}

#more {
  width: 100%;
  margin: 5px 0 0 0;
}

<div id="map"></div>
<div id="right-panel">
  <h2>Results</h2>
  <div id="number_results"></div>
  <ul id="places"></ul>
  <button id="more">More results</button>
</div>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBYoCkx3owRBY3uLwBvW36B0GNeMQtBm1o&libraries=places&callback=initMap" async defer></script>

Google API：计算位置结果

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