Google Maps V3: Draw German State Polygons? - google-maps

Question

I need to draw colored polygons over certain German states. What's the best way (or easiest, fastest, any really...) to do this? Do I need to somehow get all the outlines as lat/lon points and draw a polygon based on those? Or is there a better way?

Answer 1

You want to do something like this?
http://www.geocodezip.com/geoxml3_test/v3_FusionTables_query_sidebarF_local.html?country=Germany
It uses publicly available data in FusionTables, the Natural Earth Data set.
encrypted ID:
https://www.google.com/fusiontables/DataSource?docid=19lLpgsKdJRHL2O4fNmJ406ri9JtpIIk8a-AchA
numeric ID:
https://www.google.com/fusiontables/DataSource?dsrcid=420419
You can style them (color them) as you like.
code snippet:
// globals
var map = null;
var infoWindow = null;
var geoXml = null;
var geoXmlDoc = null;
var myLatLng = null;
var myOptions = null;
var mapCenter = null;
var geocodeTheCountry = true;
var gpolygons = [];
// Fusion Table data ID
var FT_TableID = "19lLpgsKdJRHL2O4fNmJ406ri9JtpIIk8a-AchA"; // 420419;
var CountryName = "Germany";
google.load('visualization', '1', {
'packages': ['corechart', 'table', 'geomap']
});
function createSidebar() {
// set the query using the parameters
var FT_Query2 = "SELECT 'name_0', 'name_1', 'kml_4326' FROM " + FT_TableID + " WHERE name_0 = '" + CountryName + "' ORDER by 'name_1'";
var queryText = encodeURIComponent(FT_Query2);
// alert("createSidebar query="+FT_Query2);
var query = new google.visualization.Query('http://www.google.com/fusiontables/gvizdata?tq=' + queryText);
//set the callback function
query.send(getData);
}
// Set a callback to run when the Google Visualization API is loaded.
google.setOnLoadCallback(createSidebar);
var FTresponse = null;
myLatLng = new google.maps.LatLng(37.422104808, -122.0838851);
// these set the initial center, zoom and maptype for the map
// if it is not specified in the query string
var lat = 37.422104808;
var lng = -122.0838851;
var zoom = 18;
var maptype = google.maps.MapTypeId.ROADMAP;
if (!isNaN(lat) && !isNaN(lng)) {
myLatLng = new google.maps.LatLng(lat, lng);
}
infoWindow = new google.maps.InfoWindow();
//define callback function, this is called when the results are returned
function getData(response) {
if (!response) {
alert('no response');
return;
}
if (response.isError()) {
alert('Error in query: ' + response.getMessage() + ' ' + response.getDetailedMessage());
return;
}
FTresponse = response;
//for more information on the response object, see the documentation
//http://code.google.com/apis/visualization/documentation/reference.html#QueryResponse
numRows = response.getDataTable().getNumberOfRows();
numCols = response.getDataTable().getNumberOfColumns();
fusiontabledata = "<table><tr>";
fusiontabledata += "<th>" + response.getDataTable().getColumnLabel(1) + "</th>";
// }
fusiontabledata += "</tr><tr>";
for (i = 0; i < numRows; i++) {
fusiontabledata += "<td><a href='javascript:myFTclick(" + i + ")'>" + response.getDataTable().getValue(i, 1) + "</a></td>";
// }
fusiontabledata += "</tr><tr>";
}
fusiontabledata += "</table>";
//display the results on the page
document.getElementById('sidebar').innerHTML = fusiontabledata;
}
function infoWindowContent(name, description) {
content = '<div class="FT_infowindow"><h3>' + name +
'</h3><div>' + description + '</div></div>';
return content;
}
function myFTclick(row) {
var description = FTresponse.getDataTable().getValue(row, 0);
var name = FTresponse.getDataTable().getValue(row, 1);
if (!gpolygons[row]) {
var kml = FTresponse.getDataTable().getValue(row, 2);
// create a geoXml3 parser for the click handlers
var geoXml = new geoXML3.parser({
map: map,
zoom: false,
infoWindow: infoWindow,
singleInfoWindow: true
});
geoXml.parseKmlString("<Placemark>" + kml + "</Placemark>");
geoXml.docs[0].gpolygons[0].setMap(null);
gpolygons[row] = geoXml.docs[0].gpolygons[0].bounds.getCenter();
}
var position = gpolygons[row];
if (!infoWindow) infoWindow = new google.maps.InfoWindow({});
infoWindow.setOptions({
content: infoWindowContent(name, description),
pixelOffset: new google.maps.Size(0, 2),
position: position
});
infoWindow.open(map);
}
function initialize() {
myOptions = {
zoom: zoom,
center: myLatLng,
mapTypeId: maptype
};
map = new google.maps.Map(document.getElementById("map_canvas"),
myOptions);
var geocoder = new google.maps.Geocoder();
if (geocoder && geocodeTheCountry) {
geocoder.geocode({
'address': CountryName + " Country"
}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
if (status != google.maps.GeocoderStatus.ZERO_RESULTS) {
map.setCenter(results[0].geometry.location);
map.fitBounds(results[0].geometry.viewport);
} else {
alert("No results found");
}
} else {
alert("Geocode was not successful for the following reason: " + status);
}
});
}
var FT_Query = "SELECT 'kml_4326' FROM " + FT_TableID + " WHERE 'name_0' = '" + CountryName + "';";
var FT_Options = {
suppressInfoWindows: true,
query: {
from: FT_TableID,
select: 'kml_4326',
where: "'name_0' = '" + CountryName + "';"
},
styles: [{
polygonOptions: {
fillColor: "#FF0000",
fillOpacity: 0.35
}
}]
};
layer = new google.maps.FusionTablesLayer(FT_Options);
layer.setMap(map);
google.maps.event.addListener(layer, "click", function(event) {
infoWindow.close();
infoWindow.setContent(infoWindowContent(event.row.name_1.value, event.row.name_0.value));
infoWindow.setPosition(event.latLng);
infoWindow.open(map);
});
}
google.maps.event.addDomListener(window, 'load', initialize);
html,
body {
width: 100%;
height: 100%;
margin: 0;
padding: 0;
}
#map_canvas {
width: 300px;
height: 100%
}
.infowindow * {
font-size: 90%;
margin: 0
}
<script src="https://geoxml3.googlecode.com/svn/branches/polys/geoxml3.js"></script>
<script src="http://www.google.com/jsapi"></script>
<script src="https://maps.googleapis.com/maps/api/js"></script>
<table style="width:100%; height:100%;">
<tr style="width:100%; height:90%;">
<td style="width:60%; height:100%;">
<div id="map_canvas"></div>
</td>
<td>
<div id="sidebar" style="width:300px;height:400px; overflow:auto"></div>
</td>
</tr>
</table>

Answer 2

Also, you could take a look at the Google GeoChart API, which is not that feature-rich but pretty easy to use. Try the following code in the API playground:
function drawVisualization() {
var data = google.visualization.arrayToDataTable([
['Province', 'Popularity'],
['Bremen', 100],
['Niedersachsen', 900],
['Saksen', 700],
['Saarland', 300],
['Bayern', 400]
]);
var options = {
region: 'DE',
displayMode: 'regions',
colorAxis: {colors: ['green', 'blue']},
resolution:'provinces'
};
var geochart = new google.visualization.GeoChart(
document.getElementById('visualization'));
geochart.draw(data, options, {width: 556, height: 347});
}
​