Javascript – Convert Well-known text (WKT) from MySQL to Google Maps polygons with PHP

google-mapsjavascriptphp

I have searched all over the net and i havent found any solution for this…Any solution I found doesnt work for me… I have a row with VARCHARS and an other with these GEOMETRY types, eg:

POLYGON((23.953261 37.733372,23.953623 37.733202,23.953572 37.733132,23.954075 37.732896,23.954126 37.732966,23.954550 37.732767,23.954566 37.732698,23.954467 37.732603,23.954258 37.732476,23.953007 37.733041,23.953207 37.733303,23.953261 37.733372),(23.953695 37.732771,23.954243 37.732524,23.954427 37.732635,23.954496 37.732702,23.954484 37.732757,23.954133 37.732921,23.954087 37.732859,23.953525 37.733122,23.953577 37.733192,23.953292 37.733326,23.953080 37.733050,23.953695 37.732771))

and

MULTIPOLYGON(((23.949134 37.734540,23.948811 37.734215,23.948775 37.734238,23.949077 37.734541,23.948689 37.734820,23.948809 37.734747,23.949134 37.734540)),((23.948536 37.734531,23.948449 37.734447,23.948414 37.734470,23.948472 37.734526,23.948420 37.734560,23.948449 37.734588,23.948536 37.734531)))

and simple polygons without outer rings….

I want to:
query mysql
parse data,
pass them to js
and draw them to Google Maps.
Any help with that?

Best Solution

Sounds to me like this really comes down to a regular expression question as you simply don't know how to correctly pull all the coordinate sets out of those strings, correct? Regular expressions are your friend here, do some googling about them to understand as I shall only demonstrate here.

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>Some Title</title>
</head>
<body>
<div id="map_canvas" style="width:800px; height:600px;">
</div>
<?php

$polyString1 = 'POLYGON((23.953261 37.733372,23.953623 37.733202,23.953572 37.733132,23.954075 37.732896,23.954126 37.732966,23.954550 37.732767,23.954566 37.732698,23.954467 37.732603,23.954258 37.732476,23.953007 37.733041,23.953207 37.733303,23.953261 37.733372),(23.953695 37.732771,23.954243 37.732524,23.954427 37.732635,23.954496 37.732702,23.954484 37.732757,23.954133 37.732921,23.954087 37.732859,23.953525 37.733122,23.953577 37.733192,23.953292 37.733326,23.953080 37.733050,23.953695 37.732771))';

$polyString2 = 'MULTIPOLYGON(((23.949134 37.734540,23.948811 37.734215,23.948775 37.734238,23.949077 37.734541,23.948689 37.734820,23.948809 37.734747,23.949134 37.734540)),((23.948536 37.734531,23.948449 37.734447,23.948414 37.734470,23.948472 37.734526,23.948420 37.734560,23.948449 37.734588,23.948536 37.734531)))';

echo '<script type="text/javascript">';
//note the quote styles below, Important!
echo "var polys=['$polyString1','$polyString2'];";
echo '</script>';

?>
<script src="https://maps.googleapis.com/maps/api/js?v=3&sensor=false"></script>
<script type="text/javascript">

function parsePolyStrings(ps) {
    var i, j, lat, lng, tmp, tmpArr,
        arr = [],
        //match '(' and ')' plus contents between them which contain anything other than '(' or ')'
        m = ps.match(/\([^\(\)]+\)/g);
    if (m !== null) {
        for (i = 0; i < m.length; i++) {
            //match all numeric strings
            tmp = m[i].match(/-?\d+\.?\d*/g);
            if (tmp !== null) {
                //convert all the coordinate sets in tmp from strings to Numbers and convert to LatLng objects
                for (j = 0, tmpArr = []; j < tmp.length; j+=2) {
                    lat = Number(tmp[j]);
                    lng = Number(tmp[j + 1]);
                    tmpArr.push(new google.maps.LatLng(lat, lng));
                }
                arr.push(tmpArr);
            }
        }
    }
    //array of arrays of LatLng objects, or empty array
    return arr;
}

function init() {
    var i, tmp,
        myOptions = {
            zoom: 16,
            center: new google.maps.LatLng(23.9511, 37.7337),
            mapTypeId: google.maps.MapTypeId.ROADMAP
        },
        map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
    for (i = 0; i < polys.length; i++) {
        tmp = parsePolyStrings(polys[i]);
        if (tmp.length) {
            polys[i] = new google.maps.Polygon({
                paths : tmp,
                strokeColor : '#FF0000',
                strokeOpacity : 0.8,
                strokeWeight : 2,
                fillColor : '#FF0000',
                fillOpacity : 0.35
            });
            polys[i].setMap(map);
        }
    }
}

init();

</script>
</body>
</html>
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