所以我试图遵循这里找到的教程:https://developers.google.com/maps/articles/phpsqlajax_v3
目前,我已经正确设置了数据库通信,并且另一个文件phpsqlajax_genxml2.php生成了具有所需结果的XML。
然而,当这与谷歌地图API集成时,控制台记录错误"无法读取属性'documentElement'为null",在读取"var marker = xml.documentElement.getElementsByTagName("marker");"的行,这是在downloadUrl函数调用下。
下面是index.html JS部分的一个片段:
var customIcons = {
restaurant: {
icon: 'http://labs.google.com/ridefinder/images/mm_20_blue.png'
},
bar: {
icon: 'http://labs.google.com/ridefinder/images/mm_20_red.png'
}
};
function load() {
var map = new google.maps.Map(document.getElementById("map"), {
center: new google.maps.LatLng(47.6145, -122.3418),
zoom: 13,
mapTypeId: 'roadmap'
});
var infoWindow = new google.maps.InfoWindow;
// Change this depending on the name of your PHP file
downloadUrl("phpsqlajax_genxml2.php", function(data) {
var xml = data.responseXML;
var markers = xml.documentElement.getElementsByTagName("marker");
for (var i = 0; i < markers.length; i++) {
var name = markers[i].getAttribute("name");
var address = markers[i].getAttribute("address");
var type = markers[i].getAttribute("type");
var point = new google.maps.LatLng(
parseFloat(markers[i].getAttribute("lat")),
parseFloat(markers[i].getAttribute("lng")));
var html = "<b>" + name + "</b> <br/>" + address;
var icon = customIcons[type] || {};
var marker = new google.maps.Marker({
map: map,
position: point,
icon: icon.icon
});
bindInfoWindow(marker, map, infoWindow, html);
}
});
}
function bindInfoWindow(marker, map, infoWindow, html) {
google.maps.event.addListener(marker, 'click', function() {
infoWindow.setContent(html);
infoWindow.open(map, marker);
});
}
function downloadUrl(url, callback) {
var request = window.ActiveXObject ?
new ActiveXObject('Microsoft.XMLHTTP') :
new XMLHttpRequest;
request.onreadystatechange = function() {
if (request.readyState == 4) {
request.onreadystatechange = doNothing;
callback(request, request.status);
}
};
request.open('GET', url, true);
request.send(null);
}
如果有帮助,这里是phpsqlajax_genxml2.php文件:
<?php
require("phpsqlajax_dbinfo.php");
function parseToXML($htmlStr)
{
$xmlStr=str_replace('<','<',$htmlStr);
$xmlStr=str_replace('>','>',$xmlStr);
$xmlStr=str_replace('"','"',$xmlStr);
$xmlStr=str_replace("'",''',$xmlStr);
$xmlStr=str_replace("&",'&',$xmlStr);
return $xmlStr;
}
// Opens a connection to a MySQL server
$connection=mysql_connect ('creeptrekcom.domaincommysql.com', $username, $password);
if (!$connection) {
die('Not connected : ' . mysql_error());
}
// Set the active MySQL database
$db_selected = mysql_select_db($database, $connection);
if (!$db_selected) {
die ('Can''t use db : ' . mysql_error());
}
// Select all the rows in the markers table
$query = "SELECT * FROM markers WHERE 1";
$result = mysql_query($query);
if (!$result) {
die('Invalid query: ' . mysql_error());
}
header("Content-type: text/xml");
// Start XML file, echo parent node
echo '<markers>';
// Iterate through the rows, printing XML nodes for each
while ($row = @mysql_fetch_assoc($result)){
// ADD TO XML DOCUMENT NODE
echo '<marker ';
echo 'name="' . parseToXML($row['name']) . '" ';
echo 'address="' . parseToXML($row['address']) . '" ';
echo 'lat="' . $row['lat'] . '" ';
echo 'lng="' . $row['lng'] . '" ';
echo 'type="' . $row['type'] . '" ';
echo '/>';
}
// End XML file
echo '</markers>';
?>
检查时在其源中有:
<markers>
<marker name="Pan Africa Market" address="1521 1st Ave, Seattle, WA" lat="47.608940" lng="-122.340141" type="restaurant"/>
<marker name="Buddha Thai & Bar" address="2222 2nd Ave, Seattle, WA" lat="47.613590" lng="-122.344391" type="bar"/>
<marker name="The Melting Pot" address="14 Mercer St, Seattle, WA" lat="47.624561" lng="-122.356445" type="restaurant"/>
...
</markers>
您需要允许跨域访问。您可以通过在php脚本的顶部发送正确的头文件来实现:
<?php
header("Access-Control-Allow-Origin: *");
但是要小心,因为您允许每个人访问该资源,而不仅仅是您自己!
在$result = mysql_query($query);
的php脚本中,在查询参数之前添加连接变量。
像这样:$result = mysqli_query($conn, $query);
确保数据库连接文件中的变量名称为$conn
。
示例:$conn = mysqli_connect("HOST", "USERNAME", "PASSWORD", "DATABASE");