Highlight multiple cities in google maps (Geo Chart)

This post covers information about how you can highlight regions (state,city) on Google Map using their Geo Chart API.

In this example, I will highlight the cities (metros) of USA. Lets start step by step.

First create one div in your HTML like below in which we will load the Google Map.

<div id="map_container"></div>

Then you need to reference the Google Map API library from here (we have loaded Geo chart specific module).

Now we will write some JavaScript to load the map and highlight the cities.

First I have created the object of Geo Chart by following code.

var geochart = new google.visualization.GeoChart(document.getElementById('map_container'));

Then I have defined data table which has the two column data, in first column I have specified the DMA Region code of the city and in second I have specified the index of the color (as defined in options).

(In Google Map, to highlight city we need to use their respective DMA Region Code, you can find/download the all list here )

In this example, I have used following cities and their respective DMA region codes.

• 619 - Springfield, MO
• 803 - Los Angeles, CA
• 545 - Greenville-New Bern-Washington, NC
• 630 - Birmingham, AL
• 800 - Bakersfield, CA
• 698 - Montgomery (Selma), AL
• 522 - Columbus, GA

Now I have created a set of options in which I have also specified the colors to highlight above cities.

  var options = {
            displayMode: 'regions',
            region: "US",
            legend: "none",
            width: 600,
            height: 500,
            resolution: 'metros',
            colors: ['red', 'blue', 'orange']
  };

(To know in detail about different configuration options you can visit this link, here you will find that "resolution=metros" is only available for US map so for the details like such you must refer this link.)

Now we have defined all the data and options so we can load the map by following code.

 geochart.draw(data, options);

That's it. Now if you run this HTML page you will find the USA map with above cities highlited in different colours.

Below is he live fiddle of the above code.

Hope you have liked this simple post. Do share your thoughts in comment section below. Thanks.