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Leaflet bindpop() using lazyload of images

I'm using leaflet to put some markers on a map. I have set that, clicking on a marker, a popup will be opened showing an image. Here's a brief example:
var map = L.map('map')
.addLayer(tile)
.setView([initLat, initLon], initZoom);
var m = L.marker([lat, lon])
.bindPopup('<img src="1.jpg"/>')
.addTo(map);
My objective is to load those images ("1.jpg" in the example above) using lazy load, so it's only loaded when I click on the marker.
Does anyone knows how to do this?
Thanks!

You could set the content of the popup when the popup is opened.
Let's create a custom popup with a lazyload option and without content :
var m = L.marker([0, 0])
.bindPopup(L.popup({
lazyload: '<img src="1.jpg"/>'
}))
.addTo(map);
You can then set a global handler to fill your popup when needed:
map.on('popupopen', function(e) {
var popen = e.popup;
if (popen.options.lazyload) {
popen.setContent(popen.options.lazyload);
}
});
And a demo:
var map = L.map('map', {
center: [0, 0],
zoom: 1
});
var m = L.marker([-30, 0])
.bindPopup(L.popup({
lazyload: '<img src="https://i.stack.imgur.com/shfxy.jpg?s=32&g=1" />'
}))
.addTo(map);
map.on('popupopen', function(e) {
var popen = e.popup;
if (popen.options.lazyload) {
popen.setContent(popen.options.lazyload);
}
});
html, body {
height: 100%;
margin: 0;
}
#map {
width: 100%;
height: 150px;
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.3.1/leaflet.css"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.3.1/leaflet.js"></script>
<div id='map'></div>

Actually in the case where you fill your popup with a String content (like you did with .bindPopup('<img src="1.jpg"/>'), Leaflet converts it (through innerHTML) to DOM nodes only when the Popup is first opened on a map. Therefore your image will be loaded only at that moment, which is exactly the lazy loading behaviour you are looking for.
So you do not need to do anything extra from what you already have done in your question code:
(make sure you refresh your page / clear your cache to see the image loading pass in the browser network requests)
var map = L.map('map', {
center: [0, 0],
zoom: 1
});
var m = L.marker([-30, 0])
.bindPopup('<img src="https://i.stack.imgur.com/shfxy.jpg?s=32&g=1" />')
.addTo(map);
html, body {
height: 100%;
margin: 0;
}
#map {
width: 100%;
height: 150px;
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.3.1/leaflet.css"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.3.1/leaflet.js"></script>
<div id='map'></div>

MapBox GL JS marker offset

I'm using MapBox GL JS to create a map with a custom marker:
var marker = new mapboxgl.Marker(container)
.setLngLat([
datacenters[country][city].coordinates.lng,
datacenters[country][city].coordinates.lat
])
.addTo(map);
However, I seem to have some kind of offset problem with the marker. The thing is: when zoomed out a bit, the bottom of the marker is not really pointing to the exact location:
When I'm zooming in a bit further it reaches its destination and it's pointing to the exact spot.
I really love MapBox GL, but this particular problem is bugging me and I'd love to know how to solve it. When this is fixed my implementation is far more superior to the original mapping software I was using.

From Mapbox GL JS 0.22.0 you're able to set an offset option to the marker. https://www.mapbox.com/mapbox-gl-js/api/#Marker
For example to offset the marker so that it's anchor is the middle bottom (for your pin marker) you would use:
var marker = new mapboxgl.Marker(container, {
offset: [-width / 2, -height]
})
.setLngLat([
datacenters[country][city].coordinates.lng,
datacenters[country][city].coordinates.lat
])
.addTo(map);

New solution for mapbox-gl.js v1.0.0 - Marker objects now have an anchor option to set the position to align to the marker's Lat/Lng: https://docs.mapbox.com/mapbox-gl-js/api/#marker
var marker = new mapboxgl.Marker(container, {anchor: 'bottom');
This should cover most cases and is more reliable than a pixel offset in my experience.

I've found an solution to my problem. It might be somewhat hacky, but it solves the positioning problem of the marker: I'm using a Popup fill it with a font awesome map marker icon and remove it's "tooltip styled" borders:
Javascript:
map.on('load', function() {
var container = document.createElement('div');
var icon = document.createElement('i');
icon.dataset.city = city;
icon.addEventListener('click', function(e) {
var city = e.target.dataset.city;
var country = e.target.dataset.country
flyTo(datacenters[country][city].coordinates);
});
icon.classList.add('fa', 'fa-map-marker', 'fa-2x');
container.appendChild(icon);
var popup = new mapboxgl.Popup({
closeButton: false,
closeOnClick: false
})
.setLngLat([
datacenters[country][city].coordinates.lng,
datacenters[country][city].coordinates.lat
])
.setDOMContent(container)
.addTo(map);
});
CSS:
.map div.mapboxgl-popup-content {
background: none;
padding: 0;
}
.map .mapboxgl-popup-tip {
display: none;
}
I just hope someone comes up with a real solution, because this feels kinda dirty to me. But hey: it does the job just fine!

Mapbox Marker now has an element option see this link Mapbox Marker. So instead of appending the icon HTML to the Div element you can simply add into the options when creating a marker. I found this also gets rid of the offset problem. So using the code above you can do this....
var icon = document.createElement('i');
icon.classList.add('fas', 'fa-map-marker-alt');
icon.style.color = 'blue';
new mapboxgl.Marker(container, {anchor: 'center', offset: [0, 0], element: icon})
Also the CSS for the marker can be updated to allow a pointer
.mapboxgl-marker {
border: none;
cursor: pointer;
}

Pins disappearing on bing maps when map is panned

I'm trying to produce a mapping application with Bing Maps with a button that will retrieve a JSON string and places pins on the map based on the center of the map.
That is working fine, but I'm running into two issues that I'm having trouble diagnosing.
The first is that when I move the map after placing the pins, the majority of them disappear from the map except for 1-3. I've figured out that the pins are still being held in map.entities, but just aren't all displaying.
The second issue is that I have a click event on the pins, and sometimes when I click on a pin it will disappear (and sometimes reappear elsewhere on the map).
Here is my code:
function addPin() {
map.entities.clear();
var pinImg = "images/MapPin.jpg";
var latLong = {};
var name;
for (var i = 0; i < factualJson.response.data.length; ++i) {
latLong['latitude'] = factualJson.response.data[i].latitude;
latLong['longitude'] = factualJson.response.data[i].longitude;
name = factualJson.response.data[i].name;
var pin = new Microsoft.Maps.Pushpin(latLong, {
icon: pinImg,
anchor: new Microsoft.Maps.Point(latLong['latitude'], latLong['longitude']),
draggable: true,
width: 48,
height: 48
});
Microsoft.Maps.Events.addHandler(pin, 'click', displayName);
pin.title = name;
pin.id = 'pin' + i;
map.entities.push(pin);
}
document.getElementById("arrayLength").innerHTML = "Number of locations: " + map.entities.getLength();
}
function displayName(e) {
document.getElementById("name").innerHTML = "";
if (this.target.id != -1) {
document.getElementById("name").innerHTML = this.target.title;
}
}
function boot() {
Microsoft.Maps.loadModule('Microsoft.Maps.Overlays.Style', { callback: getMap });
}
function getMap() {
map = new Microsoft.Maps.Map($gel("bingMap"), {
credentials: getKey(),
customizeOverlays: true,
enableClickableLogo: true,
enableSearchLogo: true,
showDashboard: true,
showBreadcrumb: true,
showCopyright: true,
zoom: 10,
labelOverlay: Microsoft.Maps.LabelOverlay.hidden
});
setGeoLocation();
//setTimeout(optimizeMap, 100);
window.onresize = resizeWin;
resizeWin();
}
Currently I make an ajax call from the button, and the callback function calls 'AddPin' which adds the pins to the map. I thought I'd add in the map initialization code in case it was relevant. Currently boot() is called on body load.

For me the solution was similar to yours #canadian coder
Microsoft.Maps.Location() only accepts float values, no strings and Int.
I use MVC architecture and passed a string using a model. Later i converted that string to float and passed to Location.
Problem solved.
var pushpin = new Microsoft.Maps.Pushpin(
center, { icon: '/Content/BingPushpin.png', width: 50, height: 50, draggable: false });
pushpin.setLocation(new Microsoft.Maps.Location
(parseFloat(#Model.Latitude) , parseFloat(#Model.Longitude)));
dataLayer.push(pushpin);
locations.push(new Microsoft.Maps.Location
(parseFloat(#Model.Latitude) , parseFloat(#Model.Longitude)));
EDIT :
Later found out that problem still exist. Another reason can be that you are calling that Map to load twice. So check for any other instance of the map which is being loaded. In my case see below.
$(document).ready(function () {
loadSearchModule(); //calling Map to Load at a div without pushpins
//code to do something
getMapOnLocation();
}
function getMapOnLocation()
{//code to display map with pushpin
}
In the Above example I was telling the control to load my map with PushPins and when the page is fully Loaded load the map without pushpins.
Hope this helps :)

As always I need to ask the question before I figure it out myself.
The issue was that I needed to push a Microsoft location object into the pin and not an object. Like so:
var loc = new Microsoft.Maps.Location(47.592, -122.332);
And NOT my latLong object.
This also seemed to fix the issue of disappearing pins on click event.

Basemap Reference Layers (text) ignore Opacity on Selection-Change?

I am trying to keep my basemap layer opacity at a constant between different selections (and can be controlled by the user with a slider). Any basemap layers that don't have a related 'reference' layer behave as expected (i.e. if topo is at 25% before changing to imagery, it will update to 25% on change). If a user selects a basemap that also has a reference layer (imagery with labels; light gray canvas, etc), the reference layer ignores the opacity setting when loaded and will only change AFTER the user tries to move the slider. Thoughts?
Fun tidbit... Basemap layer 'Terrain with Labels' ignores this completely on both the imagery and the text when swapping. It almost looks like it refreshes after it loads.
Here is the working example in JSFiddle (http://jsfiddle.net/disuse/ez6mN/) and the dojo code that I am using to replicate my issue. Using the latest Esri ArcGIS Javascript 3.7.
Codeblock
var baseMap_Opacity;
var baseOpacity = 0.25;
require([
"esri/map",
"esri/dijit/BasemapGallery",
"dijit/form/HorizontalSlider",
"dijit/form/HorizontalRule",
"dijit/form/HorizontalRuleLabels",
"dojo/parser",
"dojo/dom",
"dojo/on",
"dojo/ready",
"dojo/domReady!"
], function(
Map,
BasemapGallery,
HorizontalSlider,
HorizontalRule,
HorizontalRuleLabels,
parser,
dom,
on,
ready
) {
ready(function() {
map = new Map("map", {
center: [-121.569, 39.00],
zoom: 7,
optimizePanAnimation: true,
basemap: "topo"
});
var basemapGallery = new BasemapGallery({
showArcGISBasemaps: true,
map: map
}, "basemaps");
basemapGallery.startup();
basemap = map.getLayer("layer0");
basemap.setOpacity(baseOpacity);
on(basemapGallery, "selection-change", function() {
changeBasemapOpacity(baseOpacity);
});
createHorzSlider();
});
function createHorzSlider() {
baseMap_Opacity = dom.byId("baseMap_Opacity");
baseMap_Opacity.innerHTML = Math.round(baseOpacity*100) + "%";
var horzSlider = new HorizontalSlider({
minimum: 0,
maximum: 1,
value: baseOpacity,
intermediateChanges: true,
showButtons: true,
discreteValues: 101,
style: "width: 300px; margin-left: 25px;",
onChange: function(value) {
changeBasemapOpacity(value);
}
}, "horzSlider");
horzSlider.startup();
var horzSliderRule = new HorizontalRule({
container: "bottomDecoration",
count: 2 ,
style: "height: 5px; width: 288px; margin-top: 5px; margin-left: 32px;"
}, "horzSliderRule");
horzSliderRule.startup();
var horzSliderLabels = new HorizontalRuleLabels({
container: "bottomDecoration",
labels: ["0", "100"],
style: "width: 288px; margin-left: 32px;",
labelStyle: "font-style: normal; font-weight: bold; font-size: 14px;"
}, "horzSliderLabels");
horzSliderLabels.startup();
}
function changeBasemapOpacity(value) {
baseOpacity = value;
baseMap_Opacity.innerHTML = Math.round(baseOpacity*100) + "%";
var esriURL = "http://services.arcgisonline.com";
var layers = map.getLayersVisibleAtScale();
for (var i = 0; i < layers.length; i++) {
var lyr = map.getLayer(layers[i].id);
if ((lyr._basemapGalleryLayerType) || (lyr.id == "layer0") || ((lyr.url) && (lyr.url.indexOf(esriURL) == 0))) {
lyr.setOpacity(baseOpacity);
}
}
}
});

The basemap gallery's selection-change event fires after the newly selected basemap is in the map. This fires before reference layers are added and is the intended design, the idea being that you wouldn't want to manipulate reference layers. In your case, that's not what you want so using selection-change is out.
To accomplish what you want, use the map's layer-add-result event and check if layer._basemapGalleryLayerType is truthy. If it is, you know a layer used by the basemap gallery was added to the map and you should update its opacity. Here's a code snippet:
map.on("layer-add-result", function(e) {
if ( e.layer._basemapGalleryLayerType ) {
e.layer.setOpacity(baseOpacity);
}
});
Regarding the issue with the Terrain with Labels basemap, things are working as expected. Because that basemap's reference layer includes labels as well as political boundaries and major roads, it looks like opacity isn't being applied when in fact it is. Using the code above will set opacity on both the layer that represents the terrain basemap as well as the reference layer.
Here's a modified version of your page that I think accomplishes what you want: http://jsbin.com/IyixAPa/1/edit

Openlayers / Openstreetmap background is vertically striped and squished

So the background of my openlayers implementation appears to be squished into vertical stripes. The weird thing is that it wasn't always like this but even when I stash all my changes back to a point where I know it was working, it still is broken. It makes me wonder if perhaps something has changed about the way the tile assets are being delivered. I have tried switching between using osm and wms layers with no change, any help would be appreciated.
Here is the pertinent code:
initMap: function() {
var view = this;
var map = this.map = new OpenLayers.Map();
map.render(this.$map[0]);
var wmsLayer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
"http://vmap0.tiles.osgeo.org/wms/vmap0?", {layers: 'basic'});
var osmLayer = new OpenLayers.Layer.OSM();
this.layers = {
point: new OpenLayers.Layer.Vector("Point Layer"),
line: new OpenLayers.Layer.Vector("Line Layer"),
polygon: new OpenLayers.Layer.Vector("Polygon Layer")
};
this.setValue(this.value);
map.addLayers([this.layers.point, this.layers.line, this.layers.polygon, osmLayer]);
drawControls = {
point: new OpenLayers.Control.DrawFeature(this.layers.point,
OpenLayers.Handler.Point),
line: new OpenLayers.Control.DrawFeature(this.layers.line,
OpenLayers.Handler.Path),
polygon: new OpenLayers.Control.DrawFeature(this.layers.polygon,
OpenLayers.Handler.Polygon)
};
this.layers[this.layerType].events.on({'sketchcomplete': function(feature) {
if (!view.multiple) {
// deactivate polygon layer once a polygon has been added
drawControls[view.layerType].deactivate();
}
}});
for(var key in drawControls) {
map.addControl(drawControls[key]);
}
if (this.layers[this.layerType].features.length) {
var bounds = this.layers[this.layerType].getDataExtent();
var zoom = this.layers[this.layerType].getZoomForExtent(bounds);
var lon = (bounds.top - bounds.bottom) / 2;
var lat = (bounds.right - bounds.left) / 2;
map.setCenter(new OpenLayers.LonLat(lon,lat), 3);
map.zoomToExtent(bounds);
if (view.multiple) {
drawControls[view.layerType].activate();
}
} else {
map.setCenter(new OpenLayers.LonLat(-11174482.03751,4861394.9982606), 4);
drawControls[view.layerType].activate();
}
this.$('.clear').click(function(e) {
e.preventDefault();
view.layers[view.layerType].destroyFeatures();
drawControls[view.layerType].activate();
});
},
Here is the output:

So I found the problem. Twitter bootstrap has a line in its reset file that sets:
img { max-width: 100% }
This was squishing the images. You can fix it by doing:
img { max-width: none; }

I was having the same problem, are you using bootstrap of twitter?
I found out there was a selector for img elements that was affecting the map. I had the next selector into the bootstrap.css"
img {
max-width: 100%;
vertical-align: middle;
border: 0;
-ms-interpolation-mode: bicubic;
}
I don't know whay the parameter max-width: 100%; makes the vertical stripes in my case. I remove the propertie max-width: 100% and now is working.

Setting img { max-width: 100% } to img { max-width:none; } does resolve the problem.
However this will have an unintended effect on images throughout your website. I am also using Bootstrap Twitter's carousel component for images and when I made the above changed the images did not fit in the carousel. Therefore I changed it so that it only targets the images in the OpenLayers / OpenStreetMap div.
div#outlet_map img { max-width:none; }