Question

我有三个Javascript函数：

功能1）从XML文件加载谷歌地图及其标记，并将其传递给功能2.

功能2）使用功能1中的数据在地图上创建标记。

功能3）使用Ajax对数据库的请求加载连接到标记/事件的用户。

我在函数2中调用函数3，这样得到字符串函数3产生：

var memberslist = showEventMembers(MapTitle)

但是当我引用字符串时，字符串undefined仅打印到HTML。我不明白为什么函数3中的值没有传递给函数2中的var memberlist。

函数3返回一个用户字符串，我已使用document.getElementById("event_members").innerHTML = this.responseText;确认了这一点，并更改了我放在脚本标记之外的div对象的文本。但是，它不能更改我在函数2中生成的span标记的html文本。

所以我需要的是将函数3的返回值传递给函数2中脚本生成的HTML标记，但是我无法使用它来替换HTML，或者将值传递给变量并使用它生成的HTML中的变量。

希望我的问题很清楚，英语不是我的第一语言，非常感谢任何帮助！

（我使用jQuery和Laravel，如果它有任何重要性，那么PHP就在Laravel＆＃34;控制器＆＃34;）。

功能1 /加载地图和标记数据：

$(document).ready(function() {
  var mapCenter = new google.maps.LatLng(47.6145, -122.3418); //Google map Coordinates


  map_initialize(); // initialize google map

  function map_initialize() {
    var googleMapOptions = {
      center: mapCenter, // map center
      zoom: 17, //zoom level, 0 = earth view to higher value
      panControl: true, //enable pan Control
      zoomControl: true, //enable zoom control
      zoomControlOptions: {
        style: google.maps.ZoomControlStyle.SMALL //zoom control size
      },
      scaleControl: true, // enable scale control
      mapTypeId: google.maps.MapTypeId.ROADMAP // google map type
    };

    map = new google.maps.Map(document.getElementById("map"), googleMapOptions);

    //var map = new google.maps.Map(document.getElementById('map'), {
    //    zoom: 4,
    //    center: {lat: -25.363882, lng: 131.044922 }
    //});     

    //Load Markers from the XML File, Check (/laravel/stumbler/stumbler/public/phppages/map_process.php)
    $.get("/laravel/stumbler/stumbler/markerxml", function(data) {
      $(data).find("marker").each(function() {
        //Get user input values for the marker from the form
        var author = $(this).attr('author');
        var name = $(this).attr('name');
        var address = '<p>' + $(this).attr('address') + '</p>';
        var type = $(this).attr('type');
        var point = new google.maps.LatLng(parseFloat($(this).attr('lat')), parseFloat($(this).attr('lng')));

        //call create_marker() function for xml loaded maker
        create_marker(author, point, name, address, false, false, false, "/laravel/stumbler/stumbler/public/images/icons/pin_blue.png");
      });
    });

    //drop a new marker on right click
    google.maps.event.addListener(map, 'rightclick', function(event) {
      //Edit form to be displayed with new marker
      var EditForm = '<p><div class="marker-edit">' +
        '</div></p>';

      //call create_marker() function
      create_marker('', event.latLng, 'Exiting event!', 'Log in or Sign up to create an event here :)', true, true, true, "/laravel/stumbler/stumbler/public/images/icons/pin_green.png");
    });
  }
});

功能2 /创建标记并放在地图上

function create_marker(MapAuth, MapPos, MapTitle, MapDesc, InfoOpenDefault, DragAble, Removable, iconPath) {
  //new marker
  var marker = new google.maps.Marker({
    position: MapPos,
    map: map,
    draggable: DragAble,
    animation: google.maps.Animation.DROP,
    title: "Hello World!",
    icon: iconPath
  });
  showEventMembers(MapTitle);
  var memberslist = showEventMembers(MapTitle);

  //Content structure of info Window for the Markers
  var contentString = $('<div class="marker-info-win">' +
    '<div class="marker-inner-win"><span class="info-content">' +
    '<h1 class="marker-heading">' + MapTitle + '</h1>' +
    MapDesc + '<p><strong>Creator: </strong>' + MapAuth + '</p>' +
    '</span>' +
    'Event members: ' + '<span id="event_members">This text is not being replaced</span><br>' +
    memberslist + //this returns the string "undefined"
    '<p><br>Sign up or Log in to join this event!</p>' +
    '</div></div>');


  //Create an infoWindow
  var infowindow = new google.maps.InfoWindow();
  //set the content of infoWindow
  infowindow.setContent(contentString[0]);

  // add click listener for the marker       
  google.maps.event.addListener(marker, 'click', function() {
    infowindow.open(map, marker); // click on marker opens info window 
  });


  if (InfoOpenDefault) //whether info window should be open by default
  {
    infowindow.open(map, marker);
  }
}

功能3 /加载与活动相关的用户

function showEventMembers(str) {

  if (str == "") {
    document.getElementById("event_members").innerHTML = "";
    return;
  } else {
    if (window.XMLHttpRequest) {
      // code for IE7+, Firefox, Chrome, Opera, Safari
      xmlhttp = new XMLHttpRequest();
    } else {
      // code for IE6, IE5
      xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }

    xmlhttp.onreadystatechange = function() {

      if (this.readyState == 4 && this.status == 200) {
        document.getElementById("event_members").innerHTML = this.responseText;
        return this.responseText;
      }
    };
    xmlhttp.open("GET", "/laravel/stumbler/stumbler/get_event_members/" + str);
    xmlhttp.send();
  }
}

PHP（返回用户和标记连接）

public function get_event_members($eventname){
$signed_up_users = DB::table('users_to_events')->where('event_name', '=', $eventname)->get();

$userlist ="";

foreach ($signed_up_users as $signed_up_user)
{
    $userlist .= $signed_up_user->username.'<br>';
}
exit($userlist);}

无法从Javascript函数返回值

0 个答案: