This sample shows how to make data features respond to mouse events.
Read the documentation .
TypeScript
const mapElement = document . querySelector ( 'gmp-map' ) as google . maps . MapElement ; let innerMap ; let lastInteractedFeatureIds : string [] = []; let lastClickedFeatureIds : string [] = []; let datasetLayer ; // Note, 'globalid' is an attribute in this Dataset. function handleClick ( /* MouseEvent */ e ) { if ( e . features ) { lastClickedFeatureIds = e . features . map ( ( f ) = > f . datasetAttributes [ 'globalid' ] ); } datasetLayer . style = applyStyle ; } function handleMouseMove ( /* MouseEvent */ e ) { if ( e . features ) { lastInteractedFeatureIds = e . features . map ( ( f ) = > f . datasetAttributes [ 'globalid' ] ); } datasetLayer . style = applyStyle ; } async function initMap () { // Request needed libraries. ( await google . maps . importLibrary ( 'maps' )) as google . maps . MapsLibrary ; // Get the inner map. innerMap = mapElement . innerMap ; // Dataset ID for NYC park data. const datasetId = 'a75dd002-ad20-4fe6-af60-27cd2ed636b4' ; datasetLayer = innerMap . getDatasetFeatureLayer ( datasetId ); datasetLayer . style = applyStyle ; datasetLayer . addListener ( 'click' , handleClick ); datasetLayer . addListener ( 'mousemove' , handleMouseMove ); // Map event listener. innerMap . addListener ( 'mousemove' , () = > { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if ( lastInteractedFeatureIds ? . length ) { lastInteractedFeatureIds = []; datasetLayer . style = applyStyle ; } }); } const styleDefault = { strokeColor : 'green' , strokeWeight : 2.0 , strokeOpacity : 1.0 , fillColor : 'green' , fillOpacity : 0.3 , }; const styleClicked = { ... styleDefault , strokeColor : 'blue' , fillColor : 'blue' , fillOpacity : 0.5 , }; const styleMouseMove = { ... styleDefault , strokeWeight : 4.0 , }; function applyStyle ( /* FeatureStyleFunctionOptions */ params ) { const datasetFeature = params . feature ; // Note, 'globalid' is an attribute in this dataset. if ( lastClickedFeatureIds . includes ( datasetFeature . datasetAttributes [ 'globalid' ] ) ) { return styleClicked ; } if ( lastInteractedFeatureIds . includes ( datasetFeature . datasetAttributes [ 'globalid' ] ) ) { return styleMouseMove ; } return styleDefault ; } initMap ();
JavaScript
const mapElement = document . querySelector ( 'gmp-map' ); let innerMap ; let lastInteractedFeatureIds = []; let lastClickedFeatureIds = []; let datasetLayer ; // Note, 'globalid' is an attribute in this Dataset. function handleClick ( /* MouseEvent */ e ) { if ( e . features ) { lastClickedFeatureIds = e . features . map (( f ) = > f . datasetAttributes [ 'globalid' ]); } datasetLayer . style = applyStyle ; } function handleMouseMove ( /* MouseEvent */ e ) { if ( e . features ) { lastInteractedFeatureIds = e . features . map (( f ) = > f . datasetAttributes [ 'globalid' ]); } datasetLayer . style = applyStyle ; } async function initMap () { // Request needed libraries. ( await google . maps . importLibrary ( 'maps' )); // Get the inner map. innerMap = mapElement . innerMap ; // Dataset ID for NYC park data. const datasetId = 'a75dd002-ad20-4fe6-af60-27cd2ed636b4' ; datasetLayer = innerMap . getDatasetFeatureLayer ( datasetId ); datasetLayer . style = applyStyle ; datasetLayer . addListener ( 'click' , handleClick ); datasetLayer . addListener ( 'mousemove' , handleMouseMove ); // Map event listener. innerMap . addListener ( 'mousemove' , () = > { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if ( lastInteractedFeatureIds ? . length ) { lastInteractedFeatureIds = []; datasetLayer . style = applyStyle ; } }); } const styleDefault = { strokeColor : 'green' , strokeWeight : 2.0 , strokeOpacity : 1.0 , fillColor : 'green' , fillOpacity : 0.3 , }; const styleClicked = { ... styleDefault , strokeColor : 'blue' , fillColor : 'blue' , fillOpacity : 0.5 , }; const styleMouseMove = { ... styleDefault , strokeWeight : 4.0 , }; function applyStyle ( /* FeatureStyleFunctionOptions */ params ) { const datasetFeature = params . feature ; // Note, 'globalid' is an attribute in this dataset. if ( lastClickedFeatureIds . includes ( datasetFeature . datasetAttributes [ 'globalid' ])) { return styleClicked ; } if ( lastInteractedFeatureIds . includes ( datasetFeature . datasetAttributes [ 'globalid' ])) { return styleMouseMove ; } return styleDefault ; } initMap ();
CSS
/* * Optional: Makes the sample page fill the window. */ html , body { height : 100 % ; margin : 0 ; padding : 0 ; } # attribution { background-color : rgba ( 255 , 255 , 255 , 0.7 ); font-family : 'Roboto' , 'Arial' , 'sans-serif' ; font-size : 10 px ; padding : 2 px ; margin : 2 px ; }
HTML
<html> <head> <title>Style a polygon data feature</title> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> <!-- prettier-ignore --> <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))}) ({key: "AIzaSyA6myHzS10YXdcazAFalmXvDkrYCp5cLc8", v: "weekly" });</script> </head> <body> <gmp-map center="40.780101, -73.967780" zoom="13" map-id="5cd2c9ca1cf05670" map-type-control="false"> <div id="attribution" slot="control-block-end-inline-start"> Data source: NYC Open Data </div> </gmp-map> </body> </html>
Try Sample
Clone Sample
Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application.
git clone https : //github.com/googlemaps-samples/js-api-samples.gitcd samples / dds - datasets - polygon - clicknpm inpm start
