How do I highlight the marker on the map when click on matching carousel corresponding to the marker to the map?

Say the first carousel slide is Los Angeles California and when click on it, the red dot marker on the map will change its color to like blue on Los Angeles, CA coordinate. When click on the 2nd slide the 1st highlighted marker will back to default red and the new marker will be highlighted to blue.

I am not sure how to go about connecting these two using Vanilla JS. If logic connects, I can easily change the red dot color using CSS.

I am using DataMaps to render the USA map with coordinates of certain cities from a JSON file and slick-carousel for the bottom carousel.

JSON

[
    {
        "city": "Madison",
        "state": "WI",
        "latitude": 43.07199845990384,
        "longitude": -89.40813691528471
    },
    {
        "city": "Columbus",
        "state": "OH",
        "latitude": 40.00178899021552,
        "longitude": -83.01964928313465
    }
]

Here I fetch the json file, initialization of DataMaps and logic for populate json objects into carousel HTMLs.

// Get JSON data
fetch('assets/json/cities.json')
  .then(function (response) {
      return response.json();
  })
  .then(function (data) {
      appendData(data);
  })
  .catch(function (err) {
      console.log('error: ' + err);
  });

var map = new Datamap({
  element: document.getElementById("map"),
  responsive: true,
  height: null,
  width: null,
  scope: 'usa',
  geographyConfig: { // USA map color
    popupOnHover: false,
    highlightOnHover: false,
    borderWidth: 1,
    borderOpacity: 0.6,
    borderColor: '#ffffff'
  },
  bubblesConfig: { // USA city popup color
    borderWidth: 1,
    borderOpacity: 1,
    borderColor: '#c5002e',
    popupOnHover: true,
    radius: null,
    fillOpacity: 1,
    animate: true,
    highlightOnHover: true,
    highlightFillColor: '#c5002e', //  hover dot color
    highlightBorderColor: '#c5002e',
    highlightBorderWidth: 1,
    highlightBorderOpacity: 1,
    highlightFillOpacity: 0.75,
    exitDelay: 100,
    key: JSON.stringify,
    popupTemplate: function(geography, data) {
      return '<div class="hoverinfo">' + data.name + '</div>';
    },
  },
    fills: {
      defaultFill: '#3a3a3a', // map color
      city: '#c5002e' //  dot color
  }
});

// Responsive map
window.addEventListener('resize', function() {
  map.resize();
});

// Loop to grab all json objects and render them in the page
function appendData(data) {
  for (var i = 0; i < data.length; i++) {
    var city = (data[i].city),
        state = (data[i].state),

    const locations = document.createElement("div");

    // Add html
    locations.innerHTML = `
      <div class="city__locations-slide">
        <div class="city__locations-slide-inner">
          <p class="">${city} ${state}</p>
        </div>
      </div>
    `;

    document.querySelector(".city__locations").append(locations)

  }

Slick-carousel code

//initilize city locations slick carousel
$(document).ready(function() {
  $(".city__locations").slick({
    dots: true,
    prevArrow: '<button type="button" class="city__locations-prev-button"/>',
    nextArrow: '<button type="button" class="city__locations-next-button"/>',
    infinite: true,
    slidesToShow: 4,
    slidesToScroll: 1,
    responsive: [
      {
        breakpoint: 1024,
        settings: {
          slidesToShow: 3,
          slidesToScroll: 1
        }
      },
      {
        breakpoint: 640,
        settings: {
          slidesToShow: 2,
          slidesToScroll: 1
        }
      },
      {
        breakpoint: 480,
        settings: {
          slidesToShow: 1,
          slidesToScroll: 1
        }
      }
    ]
  });
});

HTML

<div class="row">
    <div class="columns small-24">
      <div id="map-location" class="push--40 city__locations"></div>
  </div>
</div>

Here is initial example in jsbin.

If this all work out, there is another date feature I would like to implement it. When the current date is bigger/equal to the date in the json date object, the red dot marker will also be highlighted it.

Any help is appreciated.

Thanks!

if you can add some data attributes to the

return '<div data-unique-identifier class="hoverinfo">' + data.name + '</div>';

then with the carousel divs wire up a mouse over event and then you can use the data attributes to match the div to the corresponding icon. With the date you can again add a custom CSS class in the above line to create a highlight a bit like so:

return '<div data-unique-identifier class="' + new Date(data.someDate) === new Date('Jul 12 2011') ? highlight : hoverinfo + '">' + data.name + '</div>';

It's hard to help without a minimal reproducible example

I hope this helps