I know this is a common question, and I'm a JS newbie, but I'm completely stumped even after searching StackOverflow for hours.
I'm using the Google Maps API, and want to keep track of my markers by association with an ID. So I have var pinArray = new Object() as a global variable, and add markers like this:
function CreateMarkers (data){
data.forEach(function(store) {
<!-- CREATE MAP MARKER -->
var mapLat = store.latitude;
var mapLong = store.longitude;
var mapLatLng = { lat: parseFloat(mapLat), lng: parseFloat(mapLong) };
var marker = new google.maps.Marker({
position: mapLatLng,
title: store.name,
icon: {
path: google.maps.SymbolPath.CIRCLE,
scale: 8.5,
fillColor: 'Green',
fillOpacity: 0.8,
strokeWeight: 0.6,
},
zIndex: 0
});
cluster.addMarker(marker);
var key = store.Id;
pinArray['${key}'] = marker;
})
}
Where cluster is var cluster = new MarkerClusterer(map);.
When I try to do console.log(pinArray); back outside of the function, I get an empty object: Object {}. I've tried not using string interpolation as well, like pinArray[store.Id] = marker;, but get the same problem.
I need to keep this global associate between pins and IDs because I need to reference and update markers by their ID in other functions. Or at least, I think I do, I'm open to other ways of doing this. Help is very much appreciated; thank you in advance.
Typically when I've done something like this in the past I'll use a standard javascript array instead of an ID'd object:
var pinArray = [];
Then use push to add the markers to it as you go:
pinArray.push(Marker);
When you create the pin you can include your key in its property definition:
var marker = new google.maps.Marker({
position: mapLatLng,
title: store.name,
icon: {
path: google.maps.SymbolPath.CIRCLE,
scale: 8.5,
fillColor: 'Green',
fillOpacity: 0.8,
strokeWeight: 0.6,
},
zIndex: 0,
key: store.Id
});
and you can write a simple looping lookup function to find the individual map marker if you need to pull them by ID. Something like:
function GetMarkerByKey(key) {
var i = 0;
while (pinArray[i].key != key) {i++}
return pinArray[i];
}
Also, if you're using it in a dynamic event handler for click or hover you can use the this property to identify which marker they are activating it with.
~~~Edited to fix a syntax error~~~
var pinArray assigns the variable within the scope of function it's defined. The safest way to ensure you're defining a variable as global, regardless of where you are inside a function, is to assign it to window.
window.pinArray = new Object();
Related
So here is one of my layers:
TurksAndCaicosLayer = L.geoJson(TurksAndCaicos, {
style: {
weight: 0.5,
color: 'white',
fillOpacity: 1,
fillColor: 'brown',
}})
I have 8 of these polygon layers for my Leaflet map. I am trying to construct a loop which will go through the array of my layers and add them to the map, but it doesn't seem to be working. Can anyone spot why?
let layers = [AnguillaLayer, BermudaLayer, BritishVirginIslandsLayer, GibraltarLayer, GuernseyLayer, IsleOfManLayer, JerseyLayer, TurksAndCaicosLayer]
for (let layer of layers) {
map.addLayer(layer)}
try
layers.forEach(addLayer);
function addLayer(item, index) {
map.addLayer(item);
}
An alternative approach would be to add your layers to a layerGroup and add the layerGroup to the map - saves writing an explicit loop.
let layers = [AnguillaLayer, BermudaLayer, BritishVirginIslandsLayer, GibraltarLayer, GuernseyLayer, IsleOfManLayer, JerseyLayer, TurksAndCaicosLayer];
let myLayerGroup = L.layerGroup(layers).addTo(map);
I'm building an application using MEAN Stack and Google Maps Api and I'm having a little problem when it comes to draw Polygons and LineStrings.
I have a collection of geometries (Points, Polygons and LineStrings) and each time I find one of them I need to add it properly to the map.
I have no problem when it comes to render Markers but I have issues when it comes to Polygons and LineStrings.
Here's my code which contains the logic of initializing the map.
// Initializes the map
function initialize(latitude, longitude, filter) {
// If map has not been created...
if (!map) {
// Create a new map and place in the index.html page
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: new google.maps.LatLng(vm.selectedLat, vm.selectedLong)
});
}
// Loop through each location in the array and place a geometry
locations.forEach(function (n) {
if(n.type === 'LineString'){
console.log('LineString '+JSON.stringify(n.coords));
var linestring = new google.maps.Polyline({
position: n.coords,
map: map,
geodesic: true,
strokeColor: '#0404B4',
strokeOpacity: 1.0,
strokeWeight: 2
});
// For each linestring created, add a listener
google.maps.event.addListener(linestring, 'click', function () {
// When clicked, open the selected linestring's message
n.message.open(map, linestring);
});
linestring.setMap(map);
}
if(n.type === 'Polygon'){
console.log('Polygon '+JSON.stringify(n.coords));
var polygon = new google.maps.Polygon({
path: n.coords,
geodesic: true,
strokeColor: '#0404B4',
strokeOpacity: 0.8,
strokeWeight: 3,
fillColor: '#0404B4',
fillOpacity: 0.35
});
// For each polygon created, add a listener
google.maps.event.addListener(polygon, 'click', function () {
// When clicked, open the selected polygon's message
n.message.open(map, polygon);
});
polygon.setMap(map);
}
});
};
Here are the screenshots of the two console.log() of the coordinates
As you can see from the screenshot I also get
InvalidValueError: at index 0: not a LatLng or LatLngLiteral: in property lat: not a number
I tried, unsuccessfully, to find a solution to that.
Why can't I draw these geometries? How can I solve the InvalidValueError?
Thanks in advance.
Issues:
A google.maps.Polyline doesn't have a position property, it has a path property which takes an array of google.maps.LatLngLiterals (which looks like what you are passing in to the position property).
A google.maps.Polygon has a paths property which takes an array of google.maps.LatLngLiterals, but your data is not formatted correctly (and you are using path not paths). It is an array of {lat: [46.774, -48.19], lng: [46.466, -29.119]}, neither lat nor lng are Numbers, they are arrays.
I want to create a hole in my Javascript Google API V3, so i follow Beginning Google Map API V3. But the code is rendering the whole area. Here is my Javascript code.
(function() {
window.onload = function() {
// Creating a map
var options = {
zoom: 6,
center: new google.maps.LatLng(36.5, -79.8),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById('map'), options);
// Creating an array with the points for the outer polygon
var polyOuter = [
new google.maps.LatLng(37.303, -81.256),
new google.maps.LatLng(37.303, -78.333),
new google.maps.LatLng(35.392, -78.333),
new google.maps.LatLng(35.392, -81.256)
];
// Creating an array with the points for the inner polygon
var polyInner = [
new google.maps.LatLng(36.705, -80.459),
new google.maps.LatLng(36.705, -79),
new google.maps.LatLng(35.9, -79),
new google.maps.LatLng(35.9, -80.459)
];
var points = [polyOuter, polyInner];
// Creating the polygon
var polygon = new google.maps.Polygon
({
paths: points,
map: map,
strokeColor: '#ff0000',
strokeOpacity: 0.6,
strokeWeight: 3,
fillColor: '#FF0000',
fillOpacity: 0.35
});
};
})();
One of the paths has to be reverted so polygons are drawn in different directions, for example:
var polyInner = [
new google.maps.LatLng(35.9, -80.459),
new google.maps.LatLng(35.9, -79),
new google.maps.LatLng(36.705, -79),
new google.maps.LatLng(36.705, -80.459)
];
My assumption is that the reason is how SVG or canvas render closed loops. If I am not wrong explanation lies in nonzero winding rule. See explanation at wikipedia.
Outer path is drawn clockwise, inner path is drawn counter-clockwise.
Set a counter to zero. Pick a point in object area and draw a line in direction out of object space. If the line cross clockwise path, add one. If the line cross counter-clockwise path segment, subtract one. If the final result for selected point is non-zero, the browser fills the area. If the final result is zero, the browser does not fill it.
So, if you pick up point in the 'hole', the result will be zero and area will not be filled.
the following code is used to draw a polyline on Google Maps using V3 API, but sometimes is draws the polyline and most of times doesn't despite there are point (as I can show the points on the map as markers) but no polyline appears
update 2 : I am using openstreetmap layer over Google maps. does that cause the problem when drawing the polyilne ?
w variable contains data as string , for example :
w= 35.1212,55.2333\n36.32366,56.3333
Real data sample for w : [this code can draw markers for the following points but can't draw a polyline ]
34.440501,31.515222
34.441933,31.514346
34.44247,31.514013
34.442603,31.51394
34.443607,31.513423
34.4445,31.512926
34.444762,31.512772
34.445186,31.512523
34.445257,31.512481
34.445311,31.512449
34.445614,31.512264
34.446244,31.511867
34.446939,31.511429
34.447351,31.511193
34.448081,31.512174
34.448241,31.512357
34.448576,31.512741
34.449147,31.513185
34.4499,31.513723
34.450894,31.514401
34.451925,31.515362
34.452905,31.516176
34.454194,31.517266
34.455337,31.518236
34.456215,31.51898
34.456987,31.519646
34.457583,31.520166
34.458298,31.520772
34.458989,31.52139
34.459659,31.521959
34.460476,31.522653
34.461192,31.523228
34.461869,31.523788
34.46256,31.524376
34.463302,31.525015
34.464062,31.525668
34.464433,31.525986
34.464737,31.526246
34.465247,31.526683
34.465498,31.526907
34.466666,31.52792
34.46722,31.528404
34.467327,31.528495
34.468014,31.529081
34.468379,31.52939
34.469296,31.530177
34.469771,31.530583
34.470152,31.53091
34.470951,31.531597
34.471617,31.532172
34.472388,31.532838
34.472664,31.533076
34.47295,31.533397
34.473422,31.533653
34.474028,31.534065
34.474844,31.534629
34.475725,31.535253
34.476083,31.535517
34.476697,31.535947
34.477105,31.536209
34.477627,31.536477
34.478,31.536742
34.478398,31.536989
34.478935,31.537325
34.480044,31.537975
34.480985,31.538529
34.481362,31.53878
34.481416,31.538819
34.482407,31.539419
34.482682,31.539109
34.483132,31.538603
34.483341,31.538368
34.483917,31.537753
34.484202,31.537449
34.484288,31.537357
34.484944,31.536587
34.485118,31.536383
34.485205,31.536304
34.485648,31.535903
34.485984,31.535598
34.486246,31.535381
34.486445,31.535291
34.486533,31.535254
34.486607,31.535282
34.486706,31.535354
34.486869,31.535526
34.487012,31.535692
34.487212,31.535923
34.487273,31.536006
34.487767,31.53571
34.488336,31.535395
34.48883,31.535148
34.489078,31.535032
34.489354,31.534901
34.48955,31.534788
34.489756,31.535011
34.489831,31.535097
34.490268,31.534748
34.49065,31.534473
34.490857,31.53436
34.491044,31.534319
34.491352,31.534248
34.491458,31.534237
34.491548,31.534304
34.491879,31.534209
34.492227,31.534203
34.492457,31.534214
34.492042,31.533636
34.492162,31.533542
note : I have reversed lng and lat when creating a point for some purpose
where a is array that has the points to represent as a polyine
code
var mypolyline = new google.maps.Polyline({
strokeColor: "#FF0000",
strokeOpacity: .6,
strokeWeight: 3,
clickable: true
});
// var bounds2 = new google.maps.LatLngBounds();
var a=w.split("\n");
for(var i=0;i<a.length;i++)
{
var zz=a[i].split(",");
var lat=zz[0];
var lng=zz[1];
var path = [];
var path = mypolyline.getPath();
var point = new google.maps.LatLng(parseFloat(lng),parseFloat(lat));
createMarker(i,name,point,icon[1],2);
// alert(path.length);
path.push(point);
mypolyline.setPath(path);
mypolyline.setMap(map);
}
CreateMarker() function
function createMarker(id,name,point,icon,type) {
// var marker = new google.maps.Marker(point, customIcons[type]);
var marker = new google.maps.Marker({
map: map,
position: point,
icon: icon
});
markersArray.push(marker);
google.maps.event.addListener(marker, 'click', function() {
infowindow = new google.maps.InfoWindow({ content: name });
infowindow.open(map, marker);
map.panTo(point);
});
return marker;
}
So you create an array, then you ignore that and recreate it as an MVCArray using the getPath() function. Get rid of the first line (this isn't the cause of the problems though).
var path = [];
var path = mypolyline.getPath();
Just a thought - is the path a required attribute when you first create the polyline?
It seems to me that you initially create the mypolyline without any path. So when you then do this on the first iteration, it's not going to work, because all you're passing to .setPath() is one point, but I assume a path can only work when there's at least 2 points.
path.push(point);
mypolyline.setPath(path);
Update: I think the thing to do would be to just start out with an empty array, loop over your coordinates adding them into the array. Then after the loop, create the polyline, rather than trying to update it each time you iterate over the loop. For instance:
var a=w.split("\n");
var path = [];
for(var i=0;i<a.length;i++)
{
var zz=a[i].split(",");
var lat=zz[0];
var lng=zz[1];
var point = new google.maps.LatLng(parseFloat(lng),parseFloat(lat));
createMarker(i,name,point,icon[1],2);
path.push(point);
}
var mypolyline = new google.maps.Polyline({
path: path,
map: map,
strokeColor: "#FF0000",
strokeOpacity: .6,
strokeWeight: 3,
clickable: true
});
I'm trying to show and remove polygons onto a Google Map, using v3 of the API. In my JavaScript, I've already got an MVCArray of some custom Lat-Longs.
I'm trying to figure out how to add these polygons and then, based upon some other JavaScript event or user action, such as a click on a polygon (that has been rendered), that polygon will be removed.
Are any code examples available? I'm struggling to find some; most of them usually go to some v2 code.
In the API docs, there are a couple of simple examples of adding a polygon to a map. Here's the initialize() function from the simple Bermuda Triangle example with the addition of adding an event listener to remove the polygon when clicked.
function initialize() {
var myLatLng = new google.maps.LatLng(24.886436490787712, -70.2685546875);
var myOptions = {
zoom: 5,
center: myLatLng,
mapTypeId: google.maps.MapTypeId.TERRAIN
};
var bermudaTriangle;
var map = new google.maps.Map(document.getElementById("map_canvas"),
myOptions);
var triangleCoords = [
new google.maps.LatLng(25.774252, -80.190262),
new google.maps.LatLng(18.466465, -66.118292),
new google.maps.LatLng(32.321384, -64.75737),
new google.maps.LatLng(25.774252, -80.190262)
];
// Construct the polygon
bermudaTriangle = new google.maps.Polygon({
paths: triangleCoords,
strokeColor: "#FF0000",
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: "#FF0000",
fillOpacity: 0.35
});
bermudaTriangle.setMap(map);
// add an event listener
google.maps.event.addListener(bermudaTriangle, 'click', function() {
this.setMap(null);
});
}
I'm not sure if this answer applies to javascript, but definitely applies to java.
If you have a reference to the polygon object you want to remove, then simply call the remove() method of that polygon. Refer to the documentation linked below.
https://developers.google.com/android/reference/com/google/android/gms/maps/model/Polygon.html#remove()