CODEWITHSUNDEEP
javascriptmapboxmapbox-gl-js
n00b
n00b

Reputation: 336

How to implement mapbox expression inside Marker?

How can I add Mapbox expressions inside mapboxgl.Marker() like this one:

"icon-size": ['interpolate', ['linear'], ['zoom'], 10, 1, 15, 0.5]

(I copied this expression from here: https://stackoverflow.com/a/61036364/5220885)

Upvotes: 3

Views: 3805

Answers (3)

Ricardo Weiss
Ricardo Weiss

Reputation: 51

Adding up on @afruzan answer, if you have a list of mapboxgl.Markers, you can get the HTMLElement like this:

      for (const el of markers.current) {
    if (zoom <= 10) { el.getElement().classList.remove('zoom-10'); } else { el.getElement().classList.add('zoom-10'); }
    if (zoom <= 11) { el.getElement().classList.remove('zoom-11'); } else { el.getElement().classList.add('zoom-11'); }
    if (zoom <= 12) { el.getElement().classList.remove('zoom-12'); } else { el.getElement().classList.add('zoom-12'); }
    if (zoom <= 13) { el.getElement().classList.remove('zoom-13'); } else { el.getElement().classList.add('zoom-13'); }
    if (zoom <= 14) { el.getElement().classList.remove('zoom-14'); } else { el.getElement().classList.add('zoom-14'); }
    if (zoom <= 15) { el.getElement().classList.remove('zoom-15'); } else { el.getElement().classList.add('zoom-15'); }
    if (zoom <= 16) { el.getElement().classList.remove('zoom-16'); } else { el.getElement().classList.add('zoom-16'); }
  }
});

As you dont have the html element in the el variable, you have to user getElemet() to get the respective element

Upvotes: 1

afruzan
afruzan

Reputation: 1698

As @SteveBennett sayed:

Markers don't support expressions. They are HTML elements, and behave completely differently.

assuming you are using html native elements as markers, to have some classes and using them in styling markers, you can use this code after adding markers to map:

      for (const el of yourMarkerElements) {
        let lat = ...;
        let long = ...;

        new Marker({ element: el, anchor: 'bottom-right' })
          .setLngLat(new LngLat(long, lat))
          .addTo(map);
      }

      // use following:
      const that = this;
      map.on('zoom', () => {
        const zoom = map.getZoom();
        for (const el of yourMarkerElements) {
          if (zoom <= 10) { el.classList.remove('zoom-10'); } else { el.classList.add('zoom-10'); }
          if (zoom <= 11) { el.classList.remove('zoom-11'); } else { el.classList.add('zoom-11'); }
          if (zoom <= 12) { el.classList.remove('zoom-12'); } else { el.classList.add('zoom-12'); }
          if (zoom <= 13) { el.classList.remove('zoom-13'); } else { el.classList.add('zoom-13'); }
          if (zoom <= 14) { el.classList.remove('zoom-14'); } else { el.classList.add('zoom-14'); }
          if (zoom <= 15) { el.classList.remove('zoom-15'); } else { el.classList.add('zoom-15'); }
          if (zoom <= 16) { el.classList.remove('zoom-16'); } else { el.classList.add('zoom-16'); }
        }
      });

Upvotes: 1

Steve Bennett
Steve Bennett

Reputation: 126757

Markers don't support expressions. They are HTML elements, and behave completely differently.

You would have to fake it, along these lines:

  1. Add a handler to the map's zoom event so you can update as the map zooms in and out.
  2. Calculate a size, using regular old JavaScript.
  3. Apply that size using CSS.

Something like this:

map.on('zoom', () => {
    const scalePercent = 1 + (map.getZoom() - 8)  * 0.4;
    const svgElement = marker.getElement().children[0];
    svgElement.style.transform = `scale(${scalePercent})`;
    svgElement.style.transformOrigin = 'bottom';
});

Codepen here: https://codepen.io/stevebennett/pen/MWyXjmR?editors=1001

Upvotes: 8

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