Javascript function works on postback but not page load - javascript

I'm using a Google Maps plugin, and I want it to show up on the page load as well as all postbacks. It seems to only work on postbacks though. Any ideas? I have the body onload tag as "body background="#ccccff" onload="initialize()"", but the function is not defined the first time. Why? Here is the code:
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"> </script>
<script type="text/javascript">
var mostRecentInfo;
function initialize() {
var center = new google.maps.LatLng(0, 0);
var mapOptions = {
center: center,
zoom:1,
mapTypeId: google.maps.MapTypeId.SATELLITE
};
var map = new google.maps.Map(document.getElementById("map"), mapOptions);
var posStr = <%=JSON%>;
if (posStr.toString() != "0") {
var test = posStr.toString().split(',');
var groundstation = <%=groundStation%>;
var dateTimeStr = <%=datetimesStr%>;
var AUStr = <%=auStr%>;
var spaceCraft = <%=spacecraft%>;
var dateTimes = dateTimeStr.toString().split(',');
var auIDs = AUStr.toString().split(',');
var latitude = new Array((test.length / 2));
var longitude = new Array(latitude.length);
var i = 0;
var markerArray = new Array();
for (var j = 0; j < (test.length - 1); j = j + 2) {
latitude[i] = eval(test[j+1]);
longitude[i] = eval(test[j]);
var position = new google.maps.LatLng(latitude[i], longitude[i]);
var marker = new google.maps.Marker({
map:map,
position:position
});
markerArray.push(marker);
i++;
}
var sumLat = 0;
var sumLong = 0;
for (i = 0; i < latitude.length; i++) {
sumLat += latitude[i];
sumLong += longitude[i];
}
var avgLat = sumLat / latitude.length;
var avgLong = sumLong / longitude.length;
center = new google.maps.LatLng(avgLat, avgLong);
map.panTo(center);
var circle;
var contentStr = new Array();
for (i = 0; i < markerArray.length; i++) {
position = markerArray[i].getPosition();
var circOptions = {
strokeColor:"#770000",
strokeOpacity:0.1,
fillColor:"#881111",
fillOpacity:0.4,
map:map,
center:position,
radius:2500000
};
circle = new google.maps.Circle(circOptions);
marker = markerArray[i];
contentStr[i] = '<div id="content">' +
'<b>Spacecraft: </b>' + spaceCraft.toString() + '<br />' +
'<b>Start Time (UTC): </b>' + dateTimes[i].toString() + '<br />' +
'<b>Position: </b>(' + latitude[i].toString() + ', ' + longitude[i].toString() + ')<br />' +
'<b>AU ID: </b>' + auIDs[i] + '<br />' +
'<b>Downlink Station: </b>' + groundstation.toString() + '<br />' +
'</div>';
addListener(map, marker, contentStr[i]);
}
}
}
function addListener(map, marker, content) {
var infowindow = new google.maps.InfoWindow({
content:content
});
google.maps.event.addListener(marker, 'mouseover', function() {
if (mostRecentInfo)
mostRecentInfo.close();
mostRecentInfo = infowindow;
infowindow.open(map, this);
});
}
etc.

It is likely a timing issue with the onload function being called before the initialize function is ready. This is the reason libraries like jQuery have a document.ready function. You can try removing the onload and place a call to initialize() at the bottom of your HTML, just prior to the closing body tag. This will probably work for you.
If you have the option, I'd use a library so you can assure that the function is there and your page is ready. If you haven't tried it, give jQuery a shot.

Related

How to zoom all markers in Leaflet

This is the code I have to show the markers on the map:
var coordinates = data;
for (var i = 0; i < coordinates.length; i++) {
if (coordinates[i].x && coordinates[i].y) {
var marker = L.marker([coordinates[i].x, coordinates[i].y])
.bindPopup("Device: " + coordinates[i].device_type + '<br>' + "Time: " + coordinates[i].datetime)
.addTo(map);
}
}
It's working, but I can't zoom to view all markers in the window when I refresh the page.
I tried:
map.fitBounds(coordinates.getBounds());
But it's not working.
Update your code to:
var fg = L.featureGroup();
fg.addTo(map)
var coordinates = data;
for (var i = 0; i < coordinates.length; i++) {
if (coordinates[i].x && coordinates[i].y) {
var marker = L.marker([coordinates[i].x, coordinates[i].y])
.bindPopup("Device: " + coordinates[i].device_type + '<br>' + "Time: " + coordinates[i].datetime)
.addTo(fg);
}
}
map.fitBounds(fg.getBounds());

Make Google maps callback wait for rest of functions to finish

I am having difficulty with the way google calls its maps api. I have the following calling initMap
<script defer
src="https://maps.googleapis.com/maps/api/js?key=API_KEY_REMOVED&callback=initMap">
</script>
but inside initMap, the following condition if(getPosition() !== false) { never evaluates to true because init map is done before getPosition() has set its object values.
function initMap() {
// set new map, assign default properties
map = new google.maps.Map(document.getElementById('map'), {
center: { lat, lng }, zoom: 14
});
// check if the requested data is usable (lat, lng === numbers) before trying to use it
if(getPosition() !== false) {
map.setCenter( getPosition() ); // set latest position as the map center
addMarker();
console.log("InitMap ran here");
}
}
How can I make it so initMap waits until getPosition() has had a chance to wait for other functions to do their thing? Here is my complete script so it makes more sense.
<script>
console.log(formatTime(Date()));
// https://developers.google.com/maps/documentation/javascript/geolocation
var map; var marker;
var lat = 65.025984; var lng = 25.470794; // default map location in case no position response is available
var res_data; var res_longitude; var res_latitude; var res_speed; var res_time; // res = response (data from the ajax call)
var xhr = new XMLHttpRequest();
function getPosition() {
pos = {
lat: res_latitude,
lng: res_longitude,
};
return ( isNaN(pos.lat) || isNaN(pos.lng) ) ? false : pos; // return pos only if lat and lng values are numbers
}
function initMap() {
// set new map, assign default properties
map = new google.maps.Map(document.getElementById('map'), {
center: { lat, lng }, zoom: 14
});
// check if the requested data is usable (lat, lng === numbers) before trying to use it
if(getPosition() !== false) {
map.setCenter( getPosition() ); // set latest position as the map center
addMarker();
console.log("InitMap ran here");
}
}
// place marker on the map
function addMarker() {
//console.log("Add Marker ran");
//https://developers.google.com/maps/documentation/javascript/markers
if(marker){ marker.setMap(null); } // remove visibility of current marker
marker = new google.maps.Marker({
position: getPosition(),
map: map,
title: formatTime(res_time),
});
marker.setMap(map); // set the marker
}
function getData() {
xhr.addEventListener("load", reqListener);
xhr.open("GET", "http://example.com/data.txt");
xhr.send();
}
function reqListener() {
// res_data = long, lat, accuracy, speed, time
//console.log("reqListener: " + xhr.responseText);
res_data = '[' + xhr.responseText + ']';
res_data = JSON.parse(res_data);
res_latitude = res_data[0]; res_longitude = res_data[1]; res_accuracy = res_data[2]; res_speed = res_data[3]; res_time = res_data[4];
var formatted_time = formatTime(res_time);
document.getElementById('info').innerHTML = '<span class="info">Lat: ' + res_latitude + '</span><span class="info">Long: ' + res_longitude + '</span><span class="info">Accuracy: ' + res_accuracy + '</span><span class="info">Speed: ' + res_speed + '</span><span class="info">' + formatted_time + '</span>';
addMarker();
}
function formatTime(time) {
var t = new Date(time);
var hours, mins, secs;
if(t.getHours() < 10) { hours = "0" + t.getHours(); } else { hours = t.getHours(); }
if(t.getMinutes() < 10) { mins = "0" + t.getMinutes(); } else { mins = t.getMinutes(); }
if(t.getSeconds() < 10) { secs = "0" + t.getSeconds(); } else { secs = t.getSeconds(); }
var hms = hours +':'+ mins +':'+ secs;
return 'Updated: ' + hms;
}
function init() {
getData();
setInterval(getData, 5000);
}
init();
</script>
<script defer
src="https://maps.googleapis.com/maps/api/js?key=API_KEY_REMOVED&callback=initMap">
</script>
Get rid of the callback=initMap from where you load in the Maps API.
Instead make a call to initMap only from where you are then certain everything is loaded. e.g. at the end of reqListener.
function reqListener() {
res_data = '[' + xhr.responseText + ']';
res_data = JSON.parse(res_data);
res_latitude = res_data[0]; res_longitude = res_data[1]; res_accuracy = res_data[2]; res_speed = res_data[3]; res_time = res_data[4];
var formatted_time = formatTime(res_time);
document.getElementById('info').innerHTML = '<span class="info">Lat: ' + res_latitude + '</span><span class="info">Long: ' + res_longitude + '</span><span class="info">Accuracy: ' + res_accuracy + '</span><span class="info">Speed: ' + res_speed + '</span><span class="info">' + formatted_time + '</span>';
initMap();
addMarker();
}
If you're calling reqListener at repeated intervals and don't want to recreate your map, add some logic to the top of initMap like:
if (map !== null) {
return;
}

Change the position of infoWindow appears in Google map API v3

I' m using google map api version 3 for this program. What I m trying to do is change the position of infoWindow which appears on mouseover. Currently it shows on the marker. I want to change the position to show it on top of the marker icon. When I replace
speedTest.infoWindow.setPosition(latlng);
speedTest.infoWindow.open(speedTest.map);
These two lines with following line,
speedTest.infoWindow.open(speedTest.map, this);
It shows correctly on top of the marker. but then infoWindow will not able popup when I trigger mouse event from side items.
speedTest.showMarkers = function() {
speedTest.markers = [];
var type = 1;
if ($('usegmm').checked) {
type = 0;
}
if (speedTest.markerClusterer) {
speedTest.markerClusterer.clearMarkers();
}
var panel = $('markerlist');
panel.innerHTML = '';
var numMarkers = $('nummarkers').value;
for (var i = 0; i < numMarkers; i++) {
var titleText = speedTest.pics[i].photo_title;
if (titleText == '') {
titleText = 'No title';
}
var item = document.createElement('DIV');
var title = document.createElement('A');
title.href = '#';
title.className = 'title';
title.innerHTML = titleText;
item.appendChild(title);
panel.appendChild(item);
var latLng = new google.maps.LatLng(speedTest.pics[i].latitude,
speedTest.pics[i].longitude);
var imageUrl = 'http://chart.apis.google.com/chart?cht=mm&chs=24x32&chco=' +
'FFFFFF,008CFF,000000&ext=.png';
var markerImage = new google.maps.MarkerImage(imageUrl,
new google.maps.Size(24, 32));
var marker = new google.maps.Marker({
'position': latLng,
'icon': markerImage
});
var fn = speedTest.markerClickFunction(speedTest.pics[i], latLng);
google.maps.event.addListener(marker, 'click', fn);
google.maps.event.addDomListener(title, 'click', fn);
speedTest.markers.push(marker);
}
window.setTimeout(speedTest.time, 0);
};
speedTest.markerClickFunction = function(pic, latlng) {
return function(e) {
e.cancelBubble = true;
e.returnValue = false;
if (e.stopPropagation) {
e.stopPropagation();
e.preventDefault();
}
var title = pic.photo_title;
var url = pic.photo_url;
var fileurl = pic.photo_file_url;
var infoHtml = '<div class="info"><h3>' + title +
'</h3><div class="info-body">' +
'<a href="' + url + '" target="_blank"><img src="' +
fileurl + '" class="info-img"/></a></div>' +
'<a href="http://www.panoramio.com/" target="_blank">' +
'<img src="http://maps.google.com/intl/en_ALL/mapfiles/' +
'iw_panoramio.png"/></a><br/>' +
'<a href="' + pic.owner_url + '" target="_blank">' + pic.owner_name +
'</a></div></div>';
speedTest.infoWindow.setContent(infoHtml);
speedTest.infoWindow.setPosition(latlng);
speedTest.infoWindow.open(speedTest.map);
};
};
Here is the full code I m currently using:
speed_test_example.html
speed_test.js
When you create your marker, you can specify where the InfoWindow should be anchored, like:
var marker = new google.maps.Marker({
'position': latLng,
'icon': markerImage,
'anchorPoint': new google.maps.Point(x, y)
});
where x and y are the x and y offset from the marker's position.
Note: google.maps.MarkerImage is no longer used. Use Icon instead.

if statement inside for loop in javascript

I'm trying to learn javascript and getting hung up on this. Basically trying to run the loop and only select the values if profile[i] equals another variable named pro.
Here is the code that selects everything.
downloadUrl("phpsqlajax_genxml.php", function(data) {
var xml = data.responseXML;
var markers = xml.documentElement.getElementsByTagName("marker");
var pro="<?php echo $inform['profile']; ?>";
for (var i = 0; i < markers.length; i++) {
var profile = markers[i].getAttribute("profile");
var date = markers[i].getAttribute("date");
var catch1 = markers[i].getAttribute("catch1");
var catch2 = markers[i].getAttribute("catch2");
var catch3 = markers[i].getAttribute("catch3");
var point = new google.maps.LatLng(
parseFloat(markers[i].getAttribute("latit")),
parseFloat(markers[i].getAttribute("longit")));
var html = "<b>" + date + "</b> <br/>" + catch1 + "<br/>" + catch2 + "<br/>" + catch3;
var marker = new google.maps.Marker({
map: map,
position: point,
});
bindInfoWindow(marker, map, infoWindow, html);
I tried adding
if (profile['i'] = pro)
{
after
var profile = markers[i].getAttribute("profile");
but it still loops through the whole thing.
Any suggestions?
You are assigning instead of comparing. Use == instead.
var profile = markers[i].getAttribute("profile");
if (profile['i'] == pro)
{
var date = markers[i].getAttribute("date");
var catch1 = markers[i].getAttribute("catch1");
}

Javascript insists it's not defined, it totally is

I'm not used to writing JS, honestly, and to make matters worse I'm working with the Google Maps API which, while well-documented, is a bear. So, I've written a function that allows a users to zoom onto the map from a link. But the interpreter insists my function isn't defined when I call it. The function is "zoomTo" and it appears in the following monster script.
function load() {
if (GBrowserIsCompatible()) {
var gmarkers = [];
var htmls = [];
var i = 0;
// Read the data
//++++++++++++++++
GDownloadUrl("/assets/data/nolag.xml", function(data) {
var xml = GXml.parse(data);
var markers =
xml.documentElement.getElementsByTagName("marker");
// Draw icons
for (var i = 0; i < markers.length; i++) {
var locoName = markers[i].getAttribute("locoName");
var speed = markers[i].getAttribute("speed");
var ip = markers[i].getAttribute("ip");
var date = markers[i].getAttribute("captureTime");
var lat = markers[i].getAttribute("lat");
var lng = markers[i].getAttribute("lng");
var location = markers[i].getAttribute("location");
var heading = markers[i].getAttribute("heading");
var type = markers[i].getAttribute("type");
var point = new GLatLng(parseFloat(markers[i].getAttribute("lat")),
parseFloat(markers[i].getAttribute("lng")));
var marker = createMarker(point, locoName, speed, ip, date, lat, lng, location, heading, type);
map.addOverlay(marker);
}
});
// create the map
var map = new GMap2(document.getElementById("map"));
map.addControl(new GLargeMapControl3D());
map.addControl(new GMapTypeControl());
map.setCenter(new GLatLng(40.5500, -72.1700), 7);
map.enableScrollWheelZoom();
NEC = new GPolyline(NECRoute, "#0d004c", 3, 0.7);
map.addOverlay(NEC);
// A function to create the marker and set up the event window
//+++++++++++++++++
function createMarker(point, locoName, speed, ip, date, lat, lng, location, heading, type) {
var marker = new GMarker(point, customIcons[type]);
marker.tooltip = '<div class="tooltip"><h1>' + locoName + '</h1><h2>' + speed + '<br/>' + location + '</h2></div>';
marker.contextmenu = '<div class="contextmenu">Hello world</div>';
var satellite = "<img src=\"./images/icons/satellite.gif\">";
var gps = "<img src=\"./images/icons/gps.gif\">";
var cmu = "<img src=\"./images/icons/cmu.gif\">";
var ftp = "<img src=\"./images/icons/ftp.gif\">";
var me1k = "<img src=\"./images/icons/me1k.gif\">";
var html = "<div class=\"bubble\">";
html += "<h3>" + locoName + "<span class=\"small-data\"> Route 2150</span></h3>";;
html += "<div class=\"toolbar\">" + gps + satellite + cmu + ftp + me1k + "</div>";
html += "<h4>Heading " + heading + " # " + speed + " MPH</h4>"
html += "<h4>Lat: " + lat + "</h4><h4> Lng: " + lng + "</h4>";
html += "<h4>IP: " + ip + "</h4>";
html += "<h4><div class=\"sm-button\"><a style='color: #FFFFFF; decoration:none;' href='map_detail.php'>Details</a></div><div class=\"sm-button\">Zoom To</div></h4>";
html += "</div>";
GEvent.addListener(marker, "click", function() {
marker.openInfoWindowHtml(html);
});
gmarkers[i] = marker;
htmls[i] = html;
i++;
// ====== The new marker "mouseover" and "mouseout" listeners ======
GEvent.addListener(marker,"mouseover", function() {
showTooltip(marker);
});
GEvent.addListener(marker,"mouseout", function() {
tooltip.style.visibility="hidden"
});
return marker;
}
// ====== This function displays the tooltip ======
//+++++++++++++++++++++++++++++++++++++++++++++++++++
function showTooltip(marker) {
tooltip.innerHTML = marker.tooltip;
var point=map.getCurrentMapType().getProjection().fromLatLngToPixel(map.getBounds().getSouthWest(),map.getZoom());
var offset=map.getCurrentMapType().getProjection().fromLatLngToPixel(marker.getPoint(),map.getZoom());
var anchor=marker.getIcon().iconAnchor;
var width=marker.getIcon().iconSize.width;
var pos = new GControlPosition(G_ANCHOR_BOTTOM_LEFT, new GSize(offset.x - point.x - anchor.x + width,- offset.y + point.y +anchor.y));
pos.apply(tooltip);
tooltip.style.visibility="visible";
}
// ===== This function is invoked when the mouse goes over an entry in the side_bar =====
function mymouseover(i) {
showTooltip(gmarkers[i])
}
// ===== This function is invoked when the mouse leaves an entry in the side_bar =====
function mymouseout() {
tooltip.style.visibility="hidden";
}
// This function picks up the side_bar click and opens the corresponding info window
function myclick(i) {
gmarkers[i].openInfoWindowHtml(htmls[i]);
}
// ====== set up marker mouseover tooltip div ======
var tooltip = document.createElement("div");
document.getElementById("map").appendChild(tooltip);
tooltip.style.visibility="hidden";
// === create the context menu div ===
var contextmenu = document.createElement("div");
contextmenu.style.visibility="hidden";
// === functions that perform the context menu options ===
function zoomTo( lat, lng, level) {
// perform the requested operation
map.setCenter( new GLatLng(lat,lng), level);
// hide the context menu now that it has been used
contextmenu.style.visibility="hidden";
}
contextmenu.innerHTML = '<div class="context"><ul>'
+ '<li class="sectionheading">Zoom Out</li>'
+ '<li class="sectionheading">Boston Area</li>'
+ '<li>South Station, Boston</li>'
+ '<li>South Hampton</li>'
+ '<li>New Haven</li>'
+ '<li class="sectionheading">New York Area</li>'
+ '<li>Sunny Side</li>'
+ '<li>NY, Penn Station</li>'
+ '<li>30th Street, Philadelphia</li>'
+ '<li>Wilmington Shops</li>'
+ '<li>Baltimore, Penn Station</li>'
+ '<li class="sectionheading">DC Area</li>'
+ '<li>DC, Ivy City</li>'
+ '<li>DC, Union Station</li>'
+ '</ul</div>';
map.getContainer().appendChild(contextmenu);
// === listen for singlerightclick ===
GEvent.addListener(map,"singlerightclick",function(pixel,tile) {
clickedPixel = pixel;
var x=pixel.x;
var y=pixel.y;
if (x > map.getSize().width - 120) { x = map.getSize().width - 120 }
if (y > map.getSize().height - 100) { y = map.getSize().height - 100 }
var pos = new GControlPosition(G_ANCHOR_TOP_LEFT, new GSize(x,y));
pos.apply(contextmenu);
contextmenu.style.visibility = "visible";
});
// === If the user clicks on the map, close the context menu ===
GEvent.addListener(map, "click", function() {
contextmenu.style.visibility="hidden";
});
} else {
alert("Sorry, the Google Maps API is not compatible with this browser");
}
}
It appears that zoomTo is an annonymous function inside of the top-level function load() - therefore, it's not available to top-level calls.
Instead of
// === functions that perform the context menu options ===
function zoomTo( lat, lng, level) {
// perform the requested operation
map.setCenter( new GLatLng(lat,lng), level);
// hide the context menu now that it has been used
contextmenu.style.visibility="hidden";
}
put the function in the top level, and pass in the map and contextmenu variables:
// === functions that perform the context menu options ===
function zoomTo( lat, lng, level) {
// perform the requested operation
map.setCenter( new GLatLng(lat,lng), level);
// hide the context menu now that it has been used
contextmenu.style.visibility="hidden";
}
As it dont looks well in comment. posting the comment above here again
<html>
<head>
<script type="text/javascript">
function zoomTo(x,y,z) {
....
}
</script>
.....
</head>
......
</html>

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