Google Maps API v3 - PHP - MYSQL
GOOGLE MAPS API V3 is what I am trying to use.
I have all coordinates in mysql. I just, for example, have to take 5 lists and place them on the map, but I would like to be able to find the center based on the multiple coordinates I would like to display and the zoom level. Do you know?
I have the time of my life with something that I know is terribly simple, I just cannot understand this API. I will pay $ 20 to anyone who can help me.
//select * from mysql limit 5
//ok great we got 5 results, great job, format the 5 results so google maps like it, [name,lat,lng] whatever.
//put them on the map and let them be clickable so i can put stuff in the infowindow thing
//make the map adjust to the proper zoom level and center point
UPDATE
This is what I was looking for, hope it helps others.
credit [Chris B] for common sense math formula to get the center coordinate, sw sw is the lowest lat and lon, and ne coord is the highest lat and lon
sort($lat)&&sort($lon);
$r['c'] = array_sum($lat)/count($lat).', '.array_sum($lon)/count($lon);
$r['ne'] = $lat[count($lat)-1].', '.$lon[count($lon)-1];
$r['sw'] = $lat[0].', '.$lon[0];
var myOptions = {zoom:4,center: new google.maps.LatLng(<?php echo $r['c']; ?>),mapTypeId:google.maps.MapTypeId.ROADMAP}
var map = new google.maps.Map(document.getElementById("map_canvas"),myOptions);
<?php foreach($x as $l) echo 'new google.maps.Marker({position:new google.maps.LatLng('.$l['lat'].','.$l['lon'].'),map:map,clickable:true});'; ?>
map.fitBounds(new google.maps.LatLngBounds(new google.maps.LatLng(<?php echo $r['sw']; ?>),new google.maps.LatLng(<?php echo $r['ne']; ?>)));
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If the average / weighted center point is acceptable - you can simply average all latitudes and average all longitudes:
$latTotal = 0;
$lngTotal = 0;
foreach ($markers as $marker) {
$latTotal += $marker['lat'];
$lngTotal += $marker['lng'];
}
$centerLat = $latTotal/count($markers);
$centerLng = $lngTotal/count($markers);
Otherwise, there are some good V3 tutorials on Google .
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I used Google Maps v3 a month or two ago, but later switched to v2. However, I had the same problem as you, so I wrote a MarkerManager class for API v3. I can't find the latest version of my class, but I did find a hopefully working one. You can get it here .
I have to warn you, but this is not optimized at all and does not use overlays, so when I tried to add 50+ markers to the manager and toggle hide / show that class is sloooow ... But maybe you can have some success with it.
Usage example:
var map = new google.maps.Map(document.getElementById('MapLayerId'), {
zoom: 7,
position: new google.maps.LatLng(latitude, longitude),
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var marker1 = new google.maps.Marker({
position: new google.maps.LatLng(latitude, longitude),
map: map
});
var marker2 = new google.maps.Marker({
position: new google.maps.LatLng(latitude, longitude),
map: map
});
var manager = new MarkerManager(map, {fitBounds: true});
manager.add(marker1);
manager.add(marker2);
manager.show();
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GDownloadUrl in V2 equivalent downloadUrl in GOOGLE MAPS API V3
How to load all coordinates in a database (Mysql or Sql).
var myLatlng = new google.maps.LatLng("37.427770" ,"-122.144841");
var myOptions = {zoom: 15, center: myLatlng, mapTypeId: google.maps.MapTypeId.ROADMAP,}
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
var url='marker.php?arg1=x&arg2=y...';
downloadUrl(url, function(data) {
var markers = data.documentElement.getElementsByTagName("marker");
for (var i = 0; i < markers.length; i++) {
var latlng = new google.maps.LatLng(parseFloat(markers[i].getAttribute("lat")),
parseFloat(markers[i].getAttribute("lng")));
var marker = new google.maps.Marker({position: latlng, map: map});
}
});
function createXmlHttpRequest() {
try {
if (typeof ActiveXObject != 'undefined') {
return new ActiveXObject('Microsoft.XMLHTTP');
} else if (window["XMLHttpRequest"]) {
return new XMLHttpRequest();
}
} catch (e) {
changeStatus(e);
}
return null;
};
function downloadUrl(url, callback) {
var status = -1;
var request = createXmlHttpRequest();
if (!request) {
return false;
}
request.open('GET', url);
request.onreadystatechange = function() {
if (request.readyState == 4) {
try {
status = request.status;
} catch (e) {
// Usually indicates request timed out in FF.
}
if (status == 200) {
var s=request.responseText;
callback( xmlParse(s) );
}
}
}
try {
request.send(null);
}catch (e) {
changeStatus(e);
}
};
function xmlParse(str) {
if (typeof ActiveXObject != 'undefined' && typeof GetObject != 'undefined') {
var doc = new ActiveXObject('Microsoft.XMLDOM');
doc.loadXML(str);
return doc;
}
if (typeof DOMParser != 'undefined') {
return (new DOMParser()).parseFromString(str, 'text/xml');
}
return createElement('div', null);
}
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Have you checked the official Google PHP / Mysql Curriculum? http://code.google.com/apis/maps/articles/phpsqlajax.html
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