Develop Reference

How to assign text from object to marker with same index and show relevant text after click to relevant marker? (Openlayers map)

I use OpenLayers map and I would like to get some text from var informations after click to marker. I think thant I need to have "general" function about singleclick in cycle for, because I need do it for each index [i]. But If I click to some marker I don´t see any information.
I tried to move "general" function to down before console.table(window.phpdata.markers). When I run it, I can see last text from "informations" after click on each marker --> there isn´t any problem with getting data from databases.
(This isn´t required result because I don´t want to see last marker. I would like to see relevant text from informations for relevant marker. So with same index [i].
What to do for this result? Thank´s
Object.defineProperty(window.phpdata, "markers", {value: <?php echo !empty($list) ? json_encode($list) : 'null'; ?>, writable: false, configurable: false});
var base = new ol.layer.Tile({
source: new ol.source.OSM()
});
var map = new ol.Map({
target: 'map',
layers: [base],
view: new ol.View({
center: ol.proj.fromLonLat([-74.0061,40.712]), zoom: 2
})
});
var vectors = new ol.source.Vector({});
if(window.phpdata.markers && window.phpdata.markers.length > 0) {
var data = window.phpdata.markers;
for(var i = 0; i < data.length; i++) {
var informations = data[i].info;
var marker = new ol.Feature({
geometry: new ol.geom.Point(
ol.proj.fromLonLat([Number(data[i].lng), Number(data[i].lat)])
),
});
marker.setStyle(new ol.style.Style({
image: new ol.style.Icon(({
src: 'dot.png'
}))
}));
vectors.addFeature(marker);
marker.on('singleclick', function (event) { //general function to move..
if (map.hasFeatureAtPixel(event.pixel) === true) {
document.getElementById("www").innerHTML=informations;
} else {
overlay.setPosition(undefined);
closer.blur();
}
}); // //to there
}
var layer = new ol.layer.Vector({
source: vectors,
});
map.addLayer(layer);
}
document.getElementById('myposition').innerText = "click to map and get coordinates here";
map.on('singleclick', event => {
const coordinate = ol.proj.toLonLat(event.coordinate);
//const innerText = `Lon: ${coordinate[0].toFixed(4)}, Lat: ${coordinate[1].toFixed(4)}`;
const innerText = `${coordinate[0].toFixed(4)}, ${coordinate[1].toFixed(4)}`;
document.getElementById('myposition').innerText = innerText;
});
map.on('pointermove', function(evt) {
map.getTargetElement().style.cursor = map.hasFeatureAtPixel(evt.pixel) ? 'pointer' : '';
});
console.table(window.phpdata.markers)

Features do not have click events. You need to check if there are features where you click the map. You can add the info as a property to the feature and use get() to display it.
for(var i = 0; i < data.length; i++) {
var marker = new ol.Feature({
geometry: new ol.geom.Point(
ol.proj.fromLonLat([Number(data[i].lng), Number(data[i].lat)])
),
info: data[i].info
});
}
....
....
map.on('click', function(evt) {
var feature = map.forEachFeatureAtPixel(evt.pixel,
function(feature) {
return feature;
});
if (feature) {
document.getElementById("www").innerHTML = feature.get('info');
....
};
});

drawing and editing on simple image using leaflet.draw lib

I am using leaflet.draw lib. and trying to built drawing toolbar on the simple image, it displaying fine but its action doesn't works.
<div id='image-map'></div>
and my script is
<script>
url = 'images/leafletTest.png';
var bounds = [[-26.5,-25], [1021.5,1023]];
var image = L.imageOverlay(url, bounds);
map = new L.Map('image-map', {layers: [image], crs: L.CRS.Simple, minZoom : -5});
map.fitBounds(bounds);
var drawnItems = new L.FeatureGroup();
map.addLayer(drawnItems);
// Set the title to show on the polygon button
L.drawLocal.draw.toolbar.buttons.polygon = 'Draw a sexy polygon!';
var drawControl = new L.Control.Draw({
position: 'topright',
draw: {
polyline: false,
polygon: false,
circle: false,
marker: true
},
edit: {
featureGroup: drawnItems,
remove: true
}
});
map.addControl(drawControl);
map.on(L.Draw.Event.CREATED, function (e) {
var type = e.layerType,
layer = e.layer;
if (type === 'marker') {
layer.bindPopup('A popup!');
}
drawnItems.addLayer(layer);
});
map.on(L.Draw.Event.EDITED, function (e) {
var layers = e.layers;
var countOfEditedLayers = 0;
layers.eachLayer(function (layer) {
countOfEditedLayers++;
});
console.log("Edited " + countOfEditedLayers + " layers");
});
</script>
when ever i draw a rectangle or marker it doesn't display.

returning object from a javascript function with database query inside

I am trying to return the markers as the object but when i run the function it just returns [ ], but printing it inside i can see the object data, can anyone explain how to return the object batch2 please?
google.maps.event.addListener(mgr, 'loaded', function(){
mgr.addMarkers(getMarkers(),6); //add all the markers! documentation for viewports with totals for city count, look at viewport
mgr.addMarkers(getMarkers2(),14); //get markers for zoomed out place, add click function to zoom in
//mgr.addMarkers(getMarkers(1000), 8);
console.log("added");
mgr.refresh();
});
function getMarkers2() {
var batch2 = [];
var clusters = new Parse.Query("cityfreqcoords");
var clusterresults = new Parse.Object("cityfreqcoords");
clusters.find({
success: function (results) {
for (i = 1; i < results.length; i++) {
var city = (results[i]["attributes"]["city"]);
var count = (results[i]["attributes"]["count"]);
var lat = (results[i]["attributes"]["lat"]);
var lng = (results[i]["attributes"]["lng"]);
var markerLatlong = new google.maps.LatLng(lat, lng);
//icon =
//adding the marker
var marker2 = new google.maps.Marker({
position: markerLatlong,
title: city,
clickable: true,
animation: google.maps.Animation.DROP
//icon:icon
});
//adding the click event and info window
google.maps.event.addListener(marker2, 'click', function () {
map.setZoom(6);
map.setCenter(marker2.getPosition());
});
batch2.push(marker2);
}
}
})
return batch2;
}

It would appear that clusters.find is asynchronous. You return batch2 before cluster.find succeeds. There are a handful of patterns for working with asynchronous code in JavaScript -- one common one is to use a callback. You would need to rewrite your code like so:
function getMarkers2(callback) {
var batch2 = [];
var clusters = new Parse.Query("cityfreqcoords");
var clusterresults = new Parse.Object("cityfreqcoords");
clusters.find({
success: function (results) {
for (i = 1; i < results.length; i++) {
var city = (results[i]["attributes"]["city"]);
var count = (results[i]["attributes"]["count"]);
var lat = (results[i]["attributes"]["lat"]);
var lng = (results[i]["attributes"]["lng"]);
var markerLatlong = new google.maps.LatLng(lat, lng);
//icon =
//adding the marker
var marker2 = new google.maps.Marker({
position: markerLatlong,
title: city,
clickable: true,
animation: google.maps.Animation.DROP
//icon:icon
});
//adding the click event and info window
google.maps.event.addListener(marker2, 'click', function () {
map.setZoom(6);
map.setCenter(marker2.getPosition());
});
batch2.push(marker2);
}
}
callback(batch2);
})
}
Then call it like so:
getMarkers2(function(markers) {
mgr.addMarkers(markers, 14);
});
If you're interested, take a look at how promises work as you might prefer that approach over using callbacks.

With callbacks in javascript, you generally don't return data. You pass in another function reference into the handler as a callback.
EG:
function getMarkers2(f) {
// do stuff
//when done
f(batch2)
}

Ended up just passing making the marker manager global and passing mgr into the query which worked, probably not the most efficient way to do it
function getMarkers2(mgr) {
Parse.initialize("X", "Y");
var batch2 = [];
var clusters = new Parse.Query("cityfrequency2");
var clusterresults = new Parse.Object("cityfrequency2");
clusters.find({
success: function (results) {
for (i = 0; i < (results.length); i++) {
var city = (results[i]["attributes"]["city"]);
var lat = (results[i]["attributes"]["lat"]);
var lng = (results[i]["attributes"]["lng"]);
var markerLatlong = new google.maps.LatLng(lat, lng);
var image = {
url: 'warning.png',
size: new google.maps.Size(50, 46),
// The origin
origin: new google.maps.Point(0, 0),
// The anchor
anchor: new google.maps.Point(25, 0)
};
//adding the marker
var marker2 = new google.maps.Marker({
position: markerLatlong,
title: city,
clickable: true,
animation: google.maps.Animation.DROP,
icon:image
});
//adding the click event and info window
google.maps.event.addListener(marker2, 'click', function () {
map.setZoom(6);
map.setCenter();
});
batch2.push(marker2);
mgr.addMarkers(batch2,0,6);
mgr.refresh();
}
}
})
}
function setupMarkers() {
var mgrOptions = { borderPadding: 50, maxZoom: 15, trackMarkers: true };
mgr = new MarkerManager(map,mgrOptions);
google.maps.event.addListener(mgr, 'loaded', function(){
getMarkers2(mgr);
getMarkers(mgr);
console.log("added");
});
}

OL3: GetFeature from Layers by Coordinate

I want to get the Feature of a Layer by coordinate.
Furthermore I want to open this feature in a popup, which I have solved so far by an onclick event. But I want to realize by giving the coordinates of a feature and opening the popup of the featue.
I have a layer with the map and a layer with the features:
if (trackMap != null) {
for (var i = 0; i < trackMap.length; i++) {
var trackInfo = trackMap[i];
lat = parseFloat(trackInfo.lat);
lon = parseFloat(trackInfo.lon);
var layergpx = new ol.layer.Vector({
source: new ol.source.Vector({
parser: new ol.parser.GPX(),
url: '${contextRoot}/gps/gpx2' + trackInfo.url
})
});
layers.push(layergpx);
}
}
I want to get the feature of this layer in another Javascript function.
How I open a pop up by clicking on the map:
/**
* The Click Event to show the data
*/
var element = document.getElementById('popup');
var popup = new ol.Overlay({
element: element,
positioning: ol.OverlayPositioning.BOTTOM_CENTER,
stopEvent: false
});
map.addOverlay(popup);
map.on('singleclick', function(evt) {
map.getFeatures({
pixel: evt.getPixel(),
layers: vectorLayers,
success: function(layerFeatures) {
var feature = layerFeatures[0][0];
if (feature) {
var geometry = feature.getGeometry();
var coord = geometry.getCoordinates();
popup.setPosition(coord);
$(element).popover({
'placement': 'top',
'html': true,
'content': feature.get('desc')
});
$(element).popover('show');
} else {
$(element).popover('destroy');
}
}
});
});
But I want this feature not to be opened by clicking on it on the map, but by entering a coordinate in a textfield and the map opens this pop up, like in the onclick event.

Take a look at this example to see if it helps you:
http://openlayers.org/en/latest/examples/kml.html
var displayFeatureInfo = function(pixel) {
map.getFeatures({
pixel: pixel,
layers: [vector],
success: function(featuresByLayer) {
var features = featuresByLayer[0];
var info = [];
for (var i = 0, ii = features.length; i < ii; ++i) {
info.push(features[i].get('name'));
}
document.getElementById('info').innerHTML = info.join(', ') || '&nbsp';
}
});
map.getFeatures() has this success callback where it delivers the features of the layers specified in layers: [vector]. Customize it at will to get what you need.
=== Update ===
In the OpenLayers 3's Map object you have a function: getPixelFromCoordinate
/**
* #param {ol.Coordinate} coordinate Coordinate.
* #return {ol.Pixel} Pixel.
*/
ol.Map.prototype.getPixelFromCoordinate = function(coordinate) {
var frameState = this.frameState_;
if (goog.isNull(frameState)) {
return null;
} else {
var vec2 = coordinate.slice(0, 2);
return ol.vec.Mat4.multVec2(frameState.coordinateToPixelMatrix, vec2, vec2);
}
};

why map.setCenter is not working?

I have the below code in openlayers
<script defer="defer" type="text/javascript">
var map = new OpenLayers.Map('map');
var wms = new OpenLayers.Layer.WMS("OpenLayers WMS",
"http://vmap0.tiles.osgeo.org/wms/vmap0", { layers: 'basic' });
var dm_wms = new OpenLayers.Layer.WMS(
"Canadian Data",
"http://www2.dmsolutions.ca/cgi-bin/mswms_gmap",
{
layers: "bathymetry,land_fn,park,drain_fn,drainage," +
"prov_bound,fedlimit,rail,road,popplace",
transparent: "true",
format: "image/png"
}, { isBaseLayer: true }
);
var vectorLayer = new OpenLayers.Layer.Vector("Overlay");
map.setBaseLayer(vectorLayer);
OpenLayers.Geometry.Point(77.391026, 28.535516), { some: 'data' }, { externalGraphic: 'Image/map-icons/Banquet_and_Marriage_halls.png', graphicHeight: 21, graphicWidth: 21 });
var center = new OpenLayers.Geometry.Point(77.391026, 28.535516);
center.transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());
map.setCenter(new OpenLayers.LonLat(77, 28), 4);
var markers = new OpenLayers.Layer.Markers("Markers");
var ll = new OpenLayers.LonLat(77.391026, 28.535516);
var popupClass = OpenLayers.Popup.Anchored;
var popupContentHTML = '<div style="height:40px;">Hello Noida</div>';
addMarker(ll, popupClass, popupContentHTML, true);
ll = new OpenLayers.LonLat(74.613647, 30.914007);
popupClass = OpenLayers.Popup.Anchored;
popupContentHTML = '<div style="height:40px;">Hello Punjab</div>';
addMarker(ll, popupClass, popupContentHTML, true);
map.addLayers([wms, dm_wms, markers]);
var feature;
var popup = null;
function addMarker(ll, popupClass, popupContentHTML, closeBox, overflow) {
feature = new OpenLayers.Feature(markers, ll);
feature.closeBox = closeBox;
feature.popupClass = popupClass;
feature.data.popupContentHTML = popupContentHTML;
feature.data.overflow = (overflow) ? "auto" : "hidden";
var marker = feature.createMarker();
var markerClick = function (evt) {
//alert(popup);
if (popup != null)
popup.hide();
popup = this.createPopup(this.closeBox);
popup.contentSize = new OpenLayers.Size(10, 20);
map.addPopup(popup);
popup.show();
};
marker.events.register("mousedown", feature, markerClick);
markers.addMarker(marker);
}
</script>
And every thing works fine if I remove the map.setCenter(). BUt when I try to use it in my code, my map sudddenly disappears.
I also get the follwoing error in my console window:
Cannot call method 'containsLonLat' of null
I've tried every possible method on this website, but did not reach any where.. What can be the problem?

I think you put an extra Bracket in you code, try map.setCenter(new OpenLayers.LonLat(77, 28), 4); to see if it works or not.

Use leaflet https://leafletjs.com/
var map = L.map('mapid').setView([77.391026, 28.535516], 16);
L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attributionControl: true
}).addTo(map);
reference: https://leafletjs.com/examples/quick-start/