<style>
#map { position:absolute; top:0; bottom:0; width:100%; }
#currency {
z-index:9999;
position:absolute;
bottom:10px;
left:10px;
font-size:36px;
font-weight:bold;
}
</style>
<div id='currency'></div>
<div id='map'></div>
<script>
// This is example 'external data'. It's obviously very much an example,
// and in practice you'll want to use jQuery's .ajax to pull in data or
// you already have it in some other form. The important part is that
// this data has a key, like 'Canada', which exactly matches part of the
// data in the tileset - here it's that the key is the same as o.data.admin
var currencies = {
'United States of America': 'USD',
'Canada': 'CAD',
'Mexico': 'MXN'
};
var currency = document.getElementById('currency');
// This tileset, Geography Class, has interactivity defined in TileMill
// and displayed in its tooltips. If you're creating a new tileset to use
// with this technique, see the documentation on defining tooltips:
// > http://mapbox.com/tilemill/docs/crashcourse/tooltips/
// and you'll need to use fields for them to be available here -
// to hide them in tooltips but use them here, you can use something like
//
// <span style='display:none'>}</span>
//
// in the tooltip content to get TileMill to detect that the field }
// should be available in interaction.
mapbox.load('mapbox.geography-class', function(o) {
var map = mapbox.map('map');
wax.u.sanitize = function(x) { return x; };
map.addLayer(o.layer).zoom(3).center({ lat: 48, lon: -100 });
map.interaction.auto();
// This is the interactivity API. It is documented in full
// over at Wax: http://mapbox.com/wax/tooltips.html
// But basically we need to pay attention to the object coming in,
// which has `o.data` - the non-formatted data of the hovered-over feature
// and `o.e`, the event object
map.interaction.on({
on: function(o) {
// This will only listen to mousemoves. You can also look
// for clicks or any other event or combination of events.
if (o.e.type === 'mousemove') {
// If the external datasource matches the interacted-with
// feature, use it.
if (currencies[o.data.admin]) {
currency.innerHTML = currencies[o.data.admin];
} else {
currency.innerHTML = '?';
}
}
},
// When the mouse leaves the feature, clear this bit of
// interactivity
off: function() {
currency.innerHTML = '';
}
});
});
</script>