How to add more than one django-leaflet map in a view?

Question

I was able to show a map on a single page using django-leaflet. In another page, I am trying to show two (or more) maps in page but I couldn't figure out how.

For showing map in a single page:

<div class="card">
   {% leaflet_map "main" callback="map_init" %}
</div>

<script type="text/javascript">
function map_init(map, options) {
    // get point lat and lon
    var lon = "{{ project.longitude }}";
    var lat = "{{ project.latitude }}";
    // zoom to point & add it to map
    map.setView([lat, lon], 12);
    L.marker([lat, lon]).addTo(map);

}</script>

Above works fine as long as one map needs to be shown. However I am not sure how I can modify above to support multiple maps.

I have started jsfiddle page here (which is kind of blank), not sure if it's going to helpful.

What I am trying is to fill the 'img-top' div in the html below:

var locations = [
 {"lat":27.988098,"lng":86.924925},
 {"lat":27.679535,"lng":83.507020}
]

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div class="card-columns m-5">
  <div class="card">
    <div class="card-header">Location A </div>
    <div class="img-top" id="map-1" style="height:200px"></div>
    <div class="card-body">
    Some information of A
    </div>
  </div>
  
   <div class="card">
    <div class="card-header">Location B </div>
    <div class="img-top" id="map-2" style="height:200px"></div>
    <div class="card-body">
    Some information of B
    </div>
  </div>
  
</div>

Bruno A. · Answer 1 · 2018-11-21T12:06:58.107

Not very dry, but does the below work?

<div class="card">
  {% leaflet_map "map_1" callback="map_init_1" %}
</div>
<div class="card">
  {% leaflet_map "map_2" callback="map_init_2" %}
</div>

<script type="text/javascript">
  function map_init(map, lat, lon) {
    // zoom to point & add it to map
    map.setView([lat, lon], 12);
    L.marker([lat, lon]).addTo(map);
  }

  function map_init_1(map) {
    map_init(map, "{{ project1.latitude }}", "{{ project1.longitude }}")
  }

  function map2_init_2(map) {
    map_init(map, "{{ project2.latitude }}", "{{ project2.longitude }}")
  }
</script>

It seems to me that django-leaflet addresses the most simple cases. You might need to write your logic in javascript using leaflet directly to achieve what you're trying to do.

You can see what django-leaflet does when you call {% leaflet_map ... %}:

https://github.com/makinacorpus/django-leaflet/blob/master/leaflet/templates/leaflet/_leaflet_map.html

Updated JS Fiddle: https://jsfiddle.net/cdfrn53L/

EDIT:

With for loops in Django template:

{% for location in locations %}
<div class="card">
  {% leaflet_map location.div_id callback=location.callback %}
</div>
{% endfor %}

<script type="text/javascript">
  function map_init(map, lat, lon) {
    // zoom to point & add it to map
    map.setView([lat, lon], 12);
    L.marker([lat, lon]).addTo(map);
  }

  {% for location in locations %}
  function {{ location.callback }}(map) {
    map_init(map, "{{ location.lat }}", "{{ location.lon }}")
  }
  {% endfor %}
</script>

Provided your view builds a list of locations:

locations = [
    {'lat': 27.988098, 'lng': 86.924925, 'div_id': 'map-1', 'callback': 'callback_1'},
    {'lat': 27.679535, 'lng': 83.507020, 'div_id': 'map-2', 'callback': 'callback_1'}
]

You can build div_id and callback values based on the location list index.

Thank you @bruno-1. This can be useful if we know the number of maps to be created before hand. In my case I am dealing with array of locations so need bit more help. — Musa Biralo, Nov 20 '18 at 20:30
You could do a loop in the django template. I've edited my answer to explain how. — Bruno A., Nov 21 '18 at 12:07

score 0 · Accepted Answer · answered Nov 21 '18 at 14:18

This is how I was able to display the two (or more) maps dynamically in a div.

<script type="text/javascript">

items_json.forEach(item => {
    let map = L.map(item.id + "-map").setView([item.fields.latitude, item.fields.longitude], 10);
    L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
        attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
    }).addTo(map);
});

</script>

In HTML this <div class="img-top" id="{{id}}-map" style="height:200px"></div> gets filled in with the map.

Here's JS Fiddle: https://jsfiddle.net/droidxn/w7d5nqps/10/

How to add more than one django-leaflet map in a view?

2 Answers2