Develop Reference

How to add markers to leaflet map with tabletop.js?

I'm using this quite nice guide to add markers from a Google sheet to a basic leaflet.js map:
https://rdrn.me/leaflet-maps-google-sheets/
The problem is, using these code snippets here i get all the data logged and returned in the console, but none of the points appear on the map itself.
This is probably some really basic JavaScript issue that i'm not able to see. Sorry, still learning.
Here's a jfiddle, linking to a demo sheets with one marker point
https://jsfiddle.net/xfs19cz7/1/
with the map part:
function init() {
Tabletop.init({
key: '*url to gsheets here*',
callback: myFunction,
simpleSheet: true
})
}
window.addEventListener('DOMContentLoaded', init)
function myFunction(data, tabletop) {
console.log(data);
}
var map = L.map('map-div').setView([64.6220498,25.5689638], 5);
var basemap = L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attribution: 'Basemap (c) OpenStreetMap',
minZoom: 5,
maxZoom: 18
});
basemap.addTo(map);
function addPoints(data, tabletop) {
for (var row in data) {
var marker = L.marker([
data[row].Latitude,
data[row].Longitude
]).addTo(map);
marker.bindPopup('<strong>' + data[row].Info + '</strong>');
}
}
This should add one point to a basic map. Now actually the map is not at all rendered, and no marker shows up. I can't find any issues in the code making the map show up blank, but there probably are some.
The marker from gsheets is however logged in the console, i suspect there is something missing in my code relating to really basic javascript functions / looping / sloppy syntax.
Also tried the init() and addPoints(data, tabletop) parts to a map i had where the map with the same basemap link, which rendereded OK. Adding this still left the map rendering, but no markers showed up. Again, the gsheets was loaded as an array of objects.
Could anyone point me to this, probably very basic, issue in the code?
edit:
callback: myFunction,
line above needs to be changed to
callback: addPoints,
also, init function needs to be called and position set to absolute. Thanks for the working fiddle in answer marked as correct below.

Fixes
Try setting map position absolute
calling the init() function
Working fiddle

What would make a Google map Ag object returned without mapDataProvider?

I'm working on an SPA project (ionic, so it's angular with ui-router) where I need to display two different maps on two different pages/controllers.
The first map is a general map (let's call it the main map)where a few locations are marked and the second one (let's call it the edit map)is a focus on a specific location where the user can edit the location by dragging the marker.
The general implementation scheme I'm using is that I'm calling a initMap method from mappingService that instanciates a google map from each controller.
$rootScope.markers = [];
this.initMap = function initMap(mapTarget, mapCenter) {
// the initMap function initialize the map it takes two arguments:
// + mapTaget which defines the html element the map is bound to.
// + mapCenter that defines the center of the map and whether to display the center
var markup = "<div id='" + mapTarget.mapId + "'></div>";
document.getElementById(mapTarget.containerId).innerHTML = markup;
var centerPos = new google.maps.LatLng(mapCenter.lat, mapCenter.lng);
$rootScope.map = new google.maps.Map(document.getElementById(mapTarget.mapId), {
center: centerPos,
zoom: 18,
disableDefaultUI: true
});
// eventually place a person marker for the user's position
if (mapCenter.display) {
console.log('placing the position marker');
$rootScope.markers[0] = new google.maps.Marker({
position: {lat: mapCenter.lat, lng: mapCenter.lng},
map: $rootScope.map,
title: 'userLocation',
icon: './img/person_icon.png'
});
}
};
The only difference is that on the main map I'm first calling a geolocate service the return a promise and I'm using the returned location coordinates to then call the mapping service:
geolocateService.getLocalPosition()
.then(function(coords) {
mappingService.initMap(
{containerId: $scope.mapContainer, mapId: $scope.mapId},
{lat: coords.lat, lng: coords.lng, display: true}
);
While on the edit map I'm calling directly the mapping service.
mappingService.initMap(
{containerId: $scope.mapContainer, mapId: $scope.mapId},
{lat: $scope.location.lat, lng: $scope.location.lng, display: false}
);
I am able to render both maps without problem and even to add markers and some event listeners.
However, I run into the problem that after some sequence of actions, for example going from the main map to the edit map two times, one of the map would suddenly become blank (white to be exactly, so it doesn't seems to be something that I could solve by resizing the map). I'm receiving the Ag object and the only difference is that I don't get the mapDataProviders property on the broken map.
When it works, I get:
Ag object when it works
While when it doesn't, I get:
Ag object when it doesn't work
The code snippet above is my last implementation attempt. I've been trying to implement those maps from a lot of different ways to no avail. Among those attempts, I tried:
totally separates both instanciation, dividing the initMap methods into an initMainMap and an initEditMap.
using one instance for both maps and replacing the DOM element> This is what you see above with the following additional method that is called when leaving the view:
this.removeMap = function removeMap(containerId) {
var container = document.getElementById(containerId);
$rootScope.markers = [];
container.innerHTML = '';
// important part:
var old_element = container;
var new_element = old_element.cloneNode(true);
old_element.parentNode.replaceChild(new_element, old_element);
delete $rootScope.map;
}
knowing that on both views I have either:
or
<div id="edit-map-container"></div>
I'm trying to understand what would make the google map API return a map without mapDataProvider (which I believe means that the map works and even starts to render except that it lacks the tiles to display).
P.S. it looks like there is a memory leak, which is apparently a well known issue.
If anyone has the answer to this, I'm a bit lost right here!

leaflet maps - remove marker layer group and add another marker layer group

My objective here is to remove all the markers added to leaflet using layer group for a paginated listing page.When navigated to other page i am able to remove layer group of previous page, but on adding new layer group of markers(markers of next page) i am getting this error in browser and markers are not added to the map
error is - Uncaught TypeError: layer.onAdd is not a function;
code is
var leaflet_factory = {
//initializing map container
initialize: function() {
var map = L.map('mapresults');
var googleLayer = new L.Google('ROADMAP');
map.addLayer(googleLayer);
},
//set view of mao
setview: function(lat, long, zoom) {
map.setView([lat, long], zoom);
},
//add list of markers to maps
addMarkersList: function(marker_array) {
var markerArray = [];
$.each(marker_array, function(key, data) {
var marker_pointer = L.marker([data.lat, data.long]).bindPopup('<strong>' + $(this).attr('data-vendor').capitalize() + '</strong><br>' + $(this).attr('data-location').capitalize());
markerArray.push(marker_pointer);
});
window.page_makers_layer = L.layerGroup(markerArray);
window.page_makers_layer.addTo(map);
},
//remove the current marker layer group
removeMarkerLayer: function() {
map.removeLayer(window.page_makers_layer);
}
}
The problem with the above code is when calling addMarkersList for first time after initializing the map container it works.
But when i call addMarkerList with new list of markers(lat long pair) after calling removeMarkerLayer to remove existing marker layer it gives me following error which i am trying to debug.
Uncaught TypeError: layer.onAdd is not a function
Please point where i am doing wrong.

You're doing a few things wrong. Not catastrophically wrong, just antipattern wrong, e.g.:
map.removeLayer(window.page_makers_layer);
Do NOT use window globals to store references to your data (unless you're really, really, really sure of what you're doing). If you're wrapping map creation in a factory or a module, store your data in that scope.
var leaflet_factory = {
Do not name something a factory if it doesn't follow the factory pattern. It's very confusing. Just name it differently, make it a CJS module instead, or skip it entirely.
Research into common programming patterns. Do you have something that appears only once in the webpage? Consider singletons.
gives me following error which I am trying to debug.
How are you trying to debug it? Learn to use your browser debugging capabilities, and provide a complete stack trace.
You should be able to easily keep track of the value of the problematic variable, and see if it is an instance of L.LayerGroup when the call is made.

How can I list Mapbox gridLayer elements that are in the user view?

I'd like to list all of the elements from a Mapbox gridLayer that are visible to a user in the viewport.
There is an excellent example on the Mapbox site called 'Listing markers in view'. It shows all the markers on the featureLayer that are in the view of the browser.
I'd like to create something similar, but using using a gridLayer instead. (the gridLayer was created in TileMill)
Here is an example fiddle of the data with a version of non-working 'in-bounds' code:
http://jsfiddle.net/bfab/uSLVw/1/
For reference, the gridLayer has a variable in it (passed from TileMill in the UTFGrid) called '{{{Magnitude}}}' I'd like to list each of the instances of earthquakes that appear to the user, and add it to a list on the bottom left of the example. The function I'm trying to use is gridLayer.getData(latlng,callback).
Here is the snippet of code that is not working:
map.on('move', function() {
// Construct an empty list to fill with gridLayer elements.
var inBounds = [],
// Get the map bounds - the top-left and bottom-right locations.
bounds = map.getBounds();
// For each part of the grid, consider whether
// it is currently visible by comparing with the current map bounds.
// This is what fails....
myGridLayer.getData(bounds,function(earthquake){
inBounds.push(earthquake.Magnitude);
});
// Display a list of markers.
document.getElementById('coordinates').innerHTML = inBounds.join('\n');
});
Apologies if I am making a simple error...

Actually you can't (not easily at least)
1/ You misunderstand the getData function on the gridlayer
first parm is not a boundary but a location latlng
when you use this in a callback (onclick for example) you will get data only if you click on one of your circles, if not you get undefined). The data is not a list of markers but the information of your earthquake (e.g. {DateTime: "2014-04-26T16:59:15.710+00:00", Magnitude: 3.9})
myGridLayer.getData(event.latlng, function(data) {
console.log(data);
// if clicked on a marker: data is defined
// e.g. Object {DateTime: "2014-04-26T16:59:15.710+00:00", Magnitude: 3.9}
});
http://jsfiddle.net/FranceImage/uSLVw/11/
2/ It is not easy to think in terms of markers when using gridlayer as the markers are already part of the image when you load tiles:
http://a.tiles.mapbox.com/v3/bfab.i4nm0adm/3/0/2.png
The interaction is described in some javascript loaded at the same time
http://a.tiles.mapbox.com/v3/bfab.i4nm0adm/3/0/2.grid.json

How to access generated Javascript (ScriptObject) from Javascript?

I have a Silverlight application that generates a lot of Google Maps objects on the Silverlight site. For example a Map is created like this:
var map = HtmlPage.Window.CreateInstance(#"google.maps.Map", container, mapOptions);
var center = (ScriptObject)_map.Invoke("getCenter");
Everything works fine. But now I need to access the map object from Javascript directly. I think it could be done by exposing a map property as ScriptableMember and use it from Javascript. But that"s a bit odd because the map object lives already in the browser. But how do I access it?
Update
Just to make clearer what I'm talking about
Let's say I have created my map as shown above. Now I have a loaded Javasript file with this function:
function ReadMapCenter()
{
//Need the map object in Javascript
map.getCenter();
}
How can I access the existing map Object from Javascript?

If you just expose it as type ScriptObject I think the bridge will simply unpack the scripted object rather than create yet another layer of wrapping for it.
Alternative
Don't use CreateInstance
In your javascript at the global leve use:-
var map;
function createMap(container, mapOptions)
{
if (!map)
{
map = new google.maps.Map(container, mapOptions);
}
return map;
}
now your javascript has a map global it can use.
In silverlight use:-
var map = HtmlPage.Window.Invoke("createMap", container, mapOptions);