Placing a marker in Google maps - javascript

So I am preparing a page which has a Google Map and there are two forms namely latitude and longitude , and a submit button.
On entering the longitude and latitude the map is centered to the desired location and puts a marker there.
The problem I am facing is that whenever I put a new lat/long , the old marker won't go.
So basically if entered first lat/long : 10/12 , it would center to that and place a marker there, but when i enter the second lat/long (say) : 11/12 , it would center to that too and place a marker there also while the first one is not removed.
I want the page to be whenever the a new entered in the form only that one reflects in the form no old markers.
Here's my CODE :
<!DOCTYPE html>
<html>
<head>
<title>Google Maps</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<style>
html, body, #map-canvas {
margin: 0;
padding: 0;
height: 100%;
}
</style>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
<script>
var map;
function initialize() {
var mapOptions = {
zoom: 8,
center: new google.maps.LatLng(11.6667,76.2667),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
}
google.maps.event.addDomListener(window, 'load', initialize);
function pan() {
var panPoint = new google.maps.LatLng(document.getElementById("lat").value, document.getElementById("lng").value);
map.setCenter(panPoint)
var marker = new google.maps.Marker({
map: map,
position: panPoint,
});
}
</script>
</head>
<body>
Latitude:<input type="text" id="lat" >
Longitude:<input type="text" id="lng">
<input type="button" value="updateCenter" onclick="pan()" />
<div id="map-canvas"></div>
</body>
</html>
Some help would be useful

You need to clear markers each time in order to do that.
To clean marker keep marker as global variable, eg.
function pan() {
try{
marker.setMap(null);//clear marker
}
catch(err){
}
var panPoint = new google.maps.LatLng(document.getElementById("lat").value, document.getElementById("lng").value);
map.setCenter(panPoint)
//declare marker as global variable
marker = new google.maps.Marker({
map: map,
position: panPoint,
});
}
That should do the trick.

use this code
<!DOCTYPE html>
<html>
<head>
<title>Google Maps</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<style>
html, body, #map-canvas {
margin: 0;
padding: 0;
height: 100%;
}
</style>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
<script>
var map;
var markersArray=[];
function initialize() {
var mapOptions = {
zoom: 8,
center: new google.maps.LatLng(11.6667,76.2667),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
}
google.maps.event.addDomListener(window, 'load', initialize);
function pan() {
deleteOverlays();
var panPoint = new google.maps.LatLng(document.getElementById("lat").value, document.getElementById("lng").value);
map.setCenter(panPoint)
var marker = new google.maps.Marker({
map: map,
position: panPoint,
});
markersArray.push(marker);
}
function deleteOverlays() {
if (markersArray) {
for (i in markersArray) {
markersArray[i].setMap(null);
}
markersArray.length = 0;
}
}
</script>
</head>
<body>
Latitude:<input type="text" id="lat" >
Longitude:<input type="text" id="lng">
<input type="button" value="updateCenter" onclick="pan()" />
<div id="map-canvas"></div>
</body>
</html>

In the pan function before adding the new marker, try to remove all the present markers Google Maps API v3: How to remove all markers?

Related

zoom_changed listener doesn't work for me

I'm trying to use a zoom listener event in a google maps so that I can resize some axis I have in it. As a beginning, I'm trying to use an alert so that I can see whether if the listener detects a change in the zoom level or not, but I'm not able to get any alert at all. My code is the following:
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<title>Google Maps - pygmaps </title>
<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?libraries=visualization&sensor=true_or_false"></script>
<script type="text/javascript">
var map;
function initialize() {
var centerlatlng = new google.maps.LatLng(49.801674, 11.188139);
var myOptions = {
zoom: 18,
center: centerlatlng,
scaleControl:true,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
* plotting stuff *
google.maps.event.addDomListener(window, 'load',initialize);
google.maps.event.addDomListener(maps,'zoom_changed', function()
{
alert("changed");
});
</script>
</head>
<body>
<div style="text-align:center;">
<button onclick="draw_axis()">Enable/Disable Axis</button> <br><br> <div id="log"></div>
</div>
<div id="map_canvas" style="width: 100%; height: 90%;"></div>
</body>
</html>
Does anyone see the problem?
The map variable isn't defined when you create the zoom_changed listener, it is created later, when the initialize function runs (also the variable is map, not maps).
code snippet:
var map;
function initialize() {
var centerlatlng = new google.maps.LatLng(49.801674, 11.188139);
var myOptions = {
zoom: 18,
center: centerlatlng,
scaleControl: true,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
google.maps.event.addDomListener(map, 'zoom_changed', function() {
alert("changed");
});
}
google.maps.event.addDomListener(window, 'load', initialize);
html,
body,
#map_canvas {
height: 100%;
width: 100%;
margin: 0px;
padding: 0px
}
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script>
<div style="text-align:center;">
<div id="log"></div>
</div>
<div id="map_canvas" style="width: 100%; height: 90%;"></div>
You need to set zoom_changed event on the instance of google.maps.Map inside your initialize() function.
map.addListener('zoom_changed', function() {
alert("changed");
});

How set the current position center on the map?

I tried different approaches which I found on this site and in web but they don't work for me(
This is my code:
<h:panelGroup id="GMWrapper" style="background-color: red">
<p:gmap widgetVar="mainMap" center="49.835, 24.0083" zoom="15"
id="mainGoogleMap" type="HYBRID"
style="width: 600px; height: 400px" model="#{userPlaces.model}"
styleClass="gmappStyle" onPointClick="handlePointClick(event)" />
<p:commandButton onclick="someFunc()"></p:commandButton>
<script type="text/javascript">
function someFunc() {
if (navigator.geolocation) {
alert("Start")
navigator.geolocation
.getCurrentPosition(success);
alert("Successful!")
var elem = document
.getElementById("mainGoogleMap");
alert("Element was find")
elem.setCenter(new google.maps.LatLng(37.4419, -122.1419));
alert("Good done!");
} else {
error('Geo Location is not supported');
currentLat = 0.0;
currentLng = 0.0;
}
}
var currentLat;
var currentLng;
function success(position) {
currentLat = position.coords.latitude;
currentLng = position.coords.longitude;
}
</script>
</h:panelGroup>
Javascript code works to alert("Element was find")
Also I tried:
elem.setAttribute("center", currentLat.toString() + ", " + currentLng.toString());
elem.setAttribute("center", currentLat + ", " + currentLng);
elem.setAttribute("center", "37.4419, -122.1419");
and few other..
From the google maps docs: panTo(latLng:LatLng|LatLngLiteral) - Changes the center of the map to the given LatLng. If the change is less than both the width and height of the map, the transition will be smoothly animated. Below is a snippet that creates a map and centers the map at a location.
<!DOCTYPE html>
<html>
<head>
<title>Simple Map</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<style>
html, body, #map-canvas {
height: 100%;
margin: 0px;
padding: 0px
}
</style>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp"></script>
<script>
var map;
function initialize() {
var mapOptions = {
zoom: 8,
center: new google.maps.LatLng(-34.397, 150.644)
};
map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
map.panTo(new google.maps.LatLng(37.4419, -122.1419));
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body>
<div id="map-canvas"></div>
</body>
</html>

Third party latitude and longitude are not matching in google map

I have an external json which I am trying to overlay on a google map. The overall plumbing works fine.
The map gets generated. Data gets iterated, and markers are placed by reading the coordinates. But the when i look at the map the coordinates are way off on the map. The data set can not be wrong, i can give my word on that. Is there some adjustment I need to make to get this thing map to each other. Here is my code
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
html { height: 100% }
body { height: 100%; margin: 0; padding: 0 }
#map_canvas { height: 100% }
</style>
<script src="http://maps.google.com/maps/api/js?sensor=false" type="text/javascript"></script>
<script type="text/javascript">
var map;
function initialize() {
var mapOptions = {
center: new google.maps.LatLng(40.748433, -73.985655),
zoom: 11,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"),
mapOptions);
}
</script>
<script type='text/javascript' src='http://code.jquery.com/jquery-1.8.3.js'></script>
</head>
<body onload="initialize()">
<div id="map_canvas" style="width:100%; height:100%"></div>
<script type="text/javascript">
$(document).ready(function() {
var image = 'http://soumghosh.com/otherProjects/doitt/images/marker.png';
$.getJSON("http://data.cityofnewyork.us/resource/jfzu-yy6n.json", function(json1) {
$.each(json1, function(key, data) {
var latLng = new google.maps.LatLng(data.facility_address.latitude, data.facility_address.longitude);
// Creating a marker and putting it on the map
var marker = new google.maps.Marker({
position: latLng,
title: data.title,
icon:image
});
marker.setMap(map);
});
});
});
</script>
</body>
</html>

Google Maps assign a php pop-up window on clicking a marker

Assume I have put a marker at a specific location on the Map.
I want the program to open a pop-up window called bla.php when the user click on this marker.
This is what I already done to put the marker:
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
html { height: 100% }
body { height: 100%; margin: 0; padding: 0 }
#map-canvas { height: 100% }
</style>
<script type="text/javascript"
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDxVucBtLP4XefoM4syoigBgXntwkVGxv8&sensor=false">
</script>
<script type="text/javascript">
function initialize() {
var mapOptions = {
zoom: 4,
center: new google.maps.LatLng(48, 2),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
var position = new google.maps.LatLng(48,2);
var marker = new google.maps.Marker({
position: position,
map: map
});
marker.setTitle("pv-unit");
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body>
<div id="map-canvas"/>
</body>
I tried it, the whole map is not loading
First you need an event listener for your marker. Then within that, whatever code you want for opening a popup, e.g.
google.maps.event.addListener(marker, 'click', function() {
window.open('blah.php','name','height=200,width=150');
});

Javascript function doesn't run

I have a java-script function that doesn't want to run. The weird thing is that other functions in the code run fine. The function I'm having trouble with is addMarkers(). I even went so far as to copy the addMarker() function and then change the name. When I call addMarker() it runs perfectly but when I call addMarkers() it doesn't work at all despite being the same thing and being right next to the other one.
What am I missing?
var markers = [];
var map;
function initialize() {
var mapOptions = {
zoom : 2,
center : new google.maps.LatLng(0, 0),
mapTypeId : google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
}
// Sets the map on all markers in the array.
function setAllMap(map) {
for (var i = 0; i < markers.length; i++) {
markers[i].setMap(map);
}
}
// Removes the overlays from the map, but keeps them in the array.
function clearOverlays() {
setAllMap(null);
}
// Shows any overlays currently in the array.
function showOverlays() {
setAllMap(map);
}
// Deletes all markers in the array by removing references to them.
function deleteOverlays() {
clearOverlays();
markers = [];
}
function resetMap() {
map.panTo(new google.maps.LatLng(0, 0));
map.setZoom(2);
deleteOverlays();
}
function addMarker(lat, lng) {
markers.push(new google.maps.Marker({
position : new google.maps.LatLng(lat, lng),
map : map,
draggable : false,
animation : google.maps.Animation.DROP
}));
}
function addMarkers(lat, lng) {
markers.push(new google.maps.Marker({
position : new google.maps.LatLng(lat, lng),
map : map,
draggable : false,
animation : google.maps.Animation.DROP
}));
}
google.maps.event.addDomListener(window, 'load', initialize);
HTML document that runs the script
<!DOCTYPE html>
<html>
<head>
<title>Google Maps API Testing</title>
<!--meta http-equiv="refresh" content="120"-->
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<style>
html, body {
margin: 0;
padding: 0;
height: 100%;
background-color: #B0C4DE;
}
#map-canvas{
height:1020px;
width:1040px;
border: 5px black solid;
position:absolute;
top:100px;
left: 5px;
}
form{
position:relative;
left: 20px;
top: 15px;
}
</style>
<script src="https://maps.googleapis.com/maps/api/js?Key={AIzaSyBLp3nQtaofsWbtwTH4rwgOoPJ8fARnUPA}&sensor=false"></script>
<script type="text/javascript" src="maps.js"></script>
</head>
<body onload="addMarkers(0,0)">
<div id="map-canvas"></div>
<form name="form">
<input type="button" value="Reset Map" onclick="resetMap();" />
<br />
Lat: <input type="number" name="lat"/>
Lng: <input type="number" name="lng" />
<br />
<input type="button" value="Drop Icon" onclick="addMarker(form.lat.value, form.lng.value);" />
</form>
</body>
</html>
Your script, as it is, works for me(sometimes).
The issue: you have two functions that will be called onload(addMarkers and initialize).
But addMarkers will only run successfully when it will be called after initialize(otherwise map will be undefined).
As you don't have any control over the execution-order of both functions, you better move the call of addMarkers to the end of initialize.

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