I have a webapp that creates markers on a google map and I'm wondering if there is some way to locate place nearby my custom markers so users can see what is around them.
Thank you in advance,
Robert
The Places Libraryapi-doc provides the information you seek. You load the library by adding the libraries=places parameter to the URL that loads the Google Map, as shown here:
<script type="text/javascript"
src="http://maps.googleapis.com/maps/api/js?libraries=places&sensor=false">
</script>
And then you request data about places using code similar to this, copied from the Place Search Requests section of the Developer's Guide, which will search for stores within 500 meters of the point defined in the variable pyrmont:
var map;
var service;
var infowindow;
function initialize() {
var pyrmont = new google.maps.LatLng(-33.8665433,151.1956316);
map = new google.maps.Map(document.getElementById('map'), {
mapTypeId: google.maps.MapTypeId.ROADMAP,
center: pyrmont,
zoom: 15
});
var request = {
location: pyrmont,
radius: '500',
types: ['store']
};
service = new google.maps.places.PlacesService(map);
service.search(request, callback);
}
function callback(results, status) {
if (status == google.maps.places.PlacesServiceStatus.OK) {
for (var i = 0; i < results.length; i++) {
var place = results[i];
createMarker(results[i]);
}
}
}
Related
I'm having difficulty figuring out how to accomplish a specific type of Google Places API request.
I have a zipcode and i want to find out if there are any hospitals within 20 miles of the zipcode
I found the following example maps code and changed the request to hospitals but that didnt perform what i wanted.
So, to summarize, i just want an api request i can convert to PHP that contains an array of available hospitals within 20 miles of a zip code else an empty array. I could also take as an output just a boolean of yes hospitals exist or false otherwise
var sydney = new google.maps.LatLng(-33.867, 151.195);
infowindow = new google.maps.InfoWindow();
map = new google.maps.Map(
document.getElementById('map'), {center: sydney, zoom: 15});
var request = {
query: 'hospitals',
fields: ['name', 'geometry'],
};
service = new google.maps.places.PlacesService(map);
service.findPlaceFromQuery(request, function(results, status) {
if (status === google.maps.places.PlacesServiceStatus.OK) {
for (var i = 0; i < results.length; i++) {
createMarker(results[i]);
}
map.setCenter(results[0].geometry.location);
}
});
}
function createMarker(place) {
var marker = new google.maps.Marker({
map: map,
position: place.geometry.location
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.setContent(place.name);
infowindow.open(map, this);
});
}
The Nearby Search or Text Search services would be more appropriate for your use case, since you want to get multiple hospitals and not just one (Find Place returns a single place only).
Try the below code sample which displays hospitals within 20 miles of Pyrmont NSW 2009. Note that location must be a LatLng object, it can't be a zip code, but with Text Search you can add it to your query. Then set the type to hospital.
var map;
var service;
function initialize() {
var pyrmont = new google.maps.LatLng(-33.8665433,151.1956316);
map = new google.maps.Map(document.getElementById('map'), {
center: pyrmont,
zoom: 13
});
var request = {
location: pyrmont,
radius: '32186',
query: '2009',
type: 'hospital'
};
service = new google.maps.places.PlacesService(map);
service.textSearch(request, callback);
}
function callback(results, status) {
if (status == google.maps.places.PlacesServiceStatus.OK) {
for (var i = 0; i < results.length; i++) {
var place = results[i];
createMarker(results[i]);
}
}
}
function createMarker(place) {
var marker = new google.maps.Marker({
map: map,
position: place.geometry.location,
title: place.name
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.setContent(place.name);
infowindow.open(map, this);
});
}
Hope this helps!
I have a php application that stores Lng-Lat Coordinates to my database.
I would like to show all these places to a google map.
Edit: I have 6000 coordinates, I would like to do this in some way automatically.
Thank you
There are articles for that, which you can find nice and easily on Google
https://developers.google.com/maps/articles/phpsqlajax_v3
If you have several locations, you can use the following code:
var coords = [
[40.980542, 55.111786],
[42.329036, 55.222452],
[44.280249, 54.333]
];
function initialize() {
var myLatlng = new google.maps.LatLng(coords[0][0], coords[0][1]);
var myOptions = {
zoom: 4,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
var map = new google.maps.Map(document.getElementById("map"), myOptions);
for (var i = 0; i < coords.length; i++) {
var latlng = new google.maps.LatLng(coords[i][0], coords[i][1]);
var marker = new google.maps.Marker({
position: latlng,
map: map,
title: "marker : " + (i + 1)
});
}
}
google.maps.event.addDomListener(window, 'load', initialize);
Check out a working example in JSfiddle.
Also, take a look at Google Places API.
Its a service that returns information about Places using HTTP requests
I'm developing a web page with a Google Maps API v3. I currently have a functional map and search bar. I need to be able to display the distance from a searched address to the nearest placemark on one of the KML files on the map. How can I do this?
Here is the code for the page:
<script type="text/javascript">
var geocoder;
var map;
var marker;
var layers = [];
function initialize() {
geocoder = new google.maps.Geocoder ();
var latlng = new google.maps.LatLng (41, -73.4);
var myOptions = {
zoom: 7,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById("map_canvas"),
myOptions);
marker = new google.maps.Marker({map:map});
layers[0] = new google.maps.KmlLayer('http://dl.dropbox.com/u/80233620/South-and-North-County-Trailway.kml',
{preserveViewport: true});
layers[1] = new google.maps.KmlLayer('http://www.nyc.gov/html/dot/downloads/misc/cityracks.kml',
{preserveViewport: true});
layers[2] = new google.maps.KmlLayer('http://dl.dropbox.com/u/80233620/NWS%20Radar%20Images.kmz',
{preserveViewport: true});
for (var i = 0; i < layers.length; i++) {
layers[i].setMap(map);
}
}
function codeAddress () {
var address = document.getElementById ("address").value;
geocoder.geocode ( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
map.setCenter(results [0].geometry.location);
marker.setPosition(results [0].geometry.location);
map.setZoom(14);
}
else {
alert("Geocode was not successful for the following reason: " + status);
}
});
}
function toggleLayer(i) {
if(layers[i].getMap() === null) {
layers[i].setMap(map);
}
else {
layers[i].setMap(null);}
}
</script>
You cannot access the data in KML layers like that
https://developers.google.com/maps/documentation/javascript/layers#KMLLayers
Because KML may include a large number of features, you may not access
feature data from the KmlLayer object directly. Instead, as features
are displayed, they are rendered to look like clickable Maps API
overlays.
Instead you can process the XML and add markers manually, then use the geometry library and computeDistanceBetween() to get the distance. I usually multiply the distance by some number to account for turns (The distance formula gets a straight line distance). I believe around 1.2 was the most accurate.
I'm connecting a Google Map to a MySQL database to list distributors all over the world, and I seem to be having a few issues.
Sometimes the page itself will not load at all in Firefox (v4 on Mac). It's temperamental on my machine (FF v3.6 Mac) and a Windows machine (FF v4 Win 7), ok in Safari/Opera, doesn't load at all in IE 9 (Win 7). Not sure if it's a network issue or code.
Load time is pretty slow. Might be because the map covers the whole page (will create a square block to place it in).
The URL of the page is here and I used the code from Sean Feeney's page.
The code I have is:
<script src="http://maps.google.com/maps?file=api&v=2&key=<I entered my key here>" type="text/javascript"></script>
<body onUnload="GUnload()">
<div id="map" style="position:absolute;top:0px;bottom:0px;left:0;right:0;"></div>
</body>
<script type="text/javascript">
//<![CDATA[
var map;
var latlngbounds;
if (GBrowserIsCompatible()) {
function createMarker(point, address) {
var marker = new GMarker(point);
var html = address;
GEvent.addListener(marker, 'click', function() {
marker.openInfoWindowHtml(html);
});
return marker;
}
function extendBounding(point) {
latlngbounds.extend(point);
var zoom = map.getBoundsZoomLevel(latlngbounds);
if (zoom < 10) {
zoom = 12;
}
map.setCenter(latlngbounds.getCenter(), zoom);
}
}
map = new GMap2(document.getElementById("map"));
map.addControl(new GLargeMapControl3D());
map.addControl(new GMapTypeControl());
latlngbounds = new GLatLngBounds();
GDownloadUrl("genxml.php", function(data) {
var xml = GXml.parse(data);
var markers = xml.documentElement.getElementsByTagName("marker");
for (var i = 0; i < markers.length; i++) {
var address = markers[i].getAttribute("address");
var point = new GLatLng(parseFloat(markers[i].getAttribute("lat")),
parseFloat(markers[i].getAttribute("lng")));
var marker = createMarker(point, address);
map.addOverlay(marker);
extendBounding(point);
}
});
}
//]]>
</script>
The code that gets the data is the same as the example.
Any ideas as to why it doesn't always load in the browsers, and why it seems to take a while to load?
Thanks,
Adrian
Ideally you should wrap the code that loads the map inside a document ready or window load event.
I notice that your code is not nested properly inside the GBrowserIsCompatible() block so please fix that.
As far as I remember, Google maps API v2 requires you to call the setCenter() method before doing any operations on the map. So to begin with, set the center to (0, 0) immediately after creating the map.
I notice that you're downloading XML data before you add markers to the map. You must take into account the time taken by the server to serve the XML data. If you've called the setCenter() before downloading the XML, the map will display while the XML downloads asynchronously.
Inside the code that handles the XML data: when you add a marker, do not call setCenter() immediately. Doing so will cause the function to be called 1000 times if you have 1000 markers in your XML. Instead, just call latlngbounds.extend(point). Once you have iterated the loop, calculate the zoom/center and call setCenter(). This way you will end up calling this function only twice.
Edit
I've figured out what the problem is. The genxml.php randomly returns the string Google Geo error 620 occurred which cannot be parsed as XML which raises JavaScript errors and no markers are shown. Better have a look at the code of that file and see why this happens randomly. On other times when that file actually returns valid XML, the markers appear as expected.
It appears Google recently tightened geocoding requests. If you send 10 too fast, it cuts you off with 620 error. The solution they recommend is adding a dynamic timer. Other stackoverflow posts suggested a 0.25 second static timer was good enough, but I've found Google's recommendation of using a while loop that increments the timer value as needed works better. For example:
// Initialize delay in geocode speed
public $delay = 0;
public function lookup(arguments)
{
$geocode_pending = true;
while ($geocode_pending) {
$search = //address string to search;
$response = $this->performRequest($search, 'xml');
$xml = new SimpleXMLElement($response);
$status = (int) $xml->Response->Status->code;
switch ($status) {
case self::G_GEO_SUCCESS:
require_once('placemark.php');
$placemarks = array();
foreach ($xml->Response->Placemark as $placemark)
$placemarks[] = Placemark::FromSimpleXml($placemark);
$geocode_pending = false;
return $placemarks;
case self::G_GEO_TOO_MANY_QUERIES:
$delay += 100000;
case self::G_GEO_UNKNOWN_ADDRESS:
case self::G_GEO_UNAVAILABLE_ADDRESS:
return array();
default:
throw new Exception(sprintf('Google Geo error %d occurred', $status));
}
usleep($delay);
}
}
You can run your map code with window.load after everything is loaded:
jQuery(document).ready(function initAutocomplete() {
var p_lag=$('#longitude').val();
var p_lat=$('#latitude').val();
if(p_lat==''){
var p_lat=20.593684;
}
if(p_lag==''){
var p_lag=78.96288000000004 ;
}
var myLatLng = {lat: p_lat,lng: p_lag};
var map = new google.maps.Map(document.getElementById('dvMap'), {
center: myLatLng,
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var marker = new google.maps.Marker({
position: myLatLng,
draggable: true,
map: map,
title: 'Map'
});
// Create the search box and link it to the UI element.
var input = document.getElementById('pac-input');
var searchBox = new google.maps.places.SearchBox(input);
//map.controls[google.maps.ControlPosition.TOP_LEFT].push(input);
// Bias the SearchBox results towards current map's viewport.
map.addListener('bounds_changed', function () {
searchBox.setBounds(map.getBounds());
});
//Click event for getting lat lng
google.maps.event.addListener(map, 'click', function (e) {
$('input#latitude').val(e.latLng.lat());
$('input#longitude').val(e.latLng.lng());
});
google.maps.event.addListener(marker, 'dragend', function (e) {
$('input#latitude').val(e.latLng.lat());
$('input#longitude').val(e.latLng.lng());
});
var markers = [];
// [START region_getplaces]
// Listen for the event fired when the user selects a prediction and retrieve
// more details for that place.
searchBox.addListener('places_changed', function () {
var places = searchBox.getPlaces();
if (places.length == 0) {
return;
}
// Clear out the old markers.
/*markers.forEach(function (marker) {
marker.setMap(null);
});*/
markers = [];
// For each place, get the icon, name and location.
var bounds = new google.maps.LatLngBounds();
places.forEach(function (place) {
var icon = {
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)
};
// Create a marker for each place.
markers.push(new google.maps.Marker({
map: map,
icon: icon,
title: place.name,
position: place.geometry.location
}));
$('#latitude').val(place.geometry.location.lat());
$('#longitude').val(place.geometry.location.lng());
marker.setPosition(place.geometry.location);
if (place.geometry.viewport) {
// Only geocodes have viewport.
bounds.union(place.geometry.viewport);
} else {
bounds.extend(place.geometry.location);
}
map.fitBounds(bounds);
});
});
}
);
GOOGLE MAPS API V3 is what i'm trying to use.
I have all the coordinates in mysql. I just, for example, need to take 5 listings and put them on a map but I'd like to be able to find the center point based on the multiple coordinates I'd like to display, and the zoom level as well. Yeah know?
I'm having the time of my life with something that I know is terribly simple, I just can't figure this API out. I'll paypal $20 to anyone who can help me.
//select * from mysql limit 5
//ok great we got 5 results, great job, format the 5 results so google maps like it, [name,lat,lng] whatever.
//put them on the map and let them be clickable so i can put stuff in the infowindow thing
//make the map adjust to the proper zoom level and center point
UPDATE
This is what i was looking for, hope this helps others.
credit to [Chris B] for the common sense math formula for getting the center coord, the sw cord is the lowest lat and lon, and the ne coord is the greatest lat and lon
sort($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']; ?>)));
If an average/weighted center point is acceptable - you could just average all the latitudes, and average all the longitudes:
$latTotal = 0;
$lngTotal = 0;
foreach ($markers as $marker) {
$latTotal += $marker['lat'];
$lngTotal += $marker['lng'];
}
$centerLat = $latTotal/count($markers);
$centerLng = $lngTotal/count($markers);
For the rest of it, there are some good V3 tutorials on Google.
I was using Google Maps v3 a month or two back, but switched to v2 later on. 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 though - it's not optimazed at all and is not using overlays, so when I tried putting 50+ markers in the manager and toggled the hide/show the 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();
GDownloadUrl in V2 equivalent downloadUrl in GOOGLE MAPS API V3
How to load all the coordinates in 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);
}
Have you checked out the official google map PHP/Mysql tutorial?
http://code.google.com/apis/maps/articles/phpsqlajax.html
Try this algorithm for finding the centroid of a polygon:
http://tog.acm.org/resources/GraphicsGems/gemsiv/centroid.c