[RESOLVED] Make polygon Array from database

[djalecc]

Hi Peeps...

I'm a little stuck on this one, I'm sure it can be done, but just can not get my head around it all.

Here is the problem...

I have Lat & Lng stored in a database like this... which should draw a polygon on a map.

PHP

$polyPoints="50.37349614430351, -2.0654296875000106,51.56341232867588, 2.4609375,53.514184520771124, -3.427734375000007,50.37349614430351, -2.0654296875000106";

OR

$polyPoints=$row[polyPoints];

I need to get $polyPoints in to a JavaScript Array so I can use it like this...

JavaScript

var polygon = new VEShape(VEShapeType.Polygon, polyPoints);
polygon.HideIcon();
map.AddShape(polygon);

Can anyone show me the light here please! 😕

:o

[bpat1434]

Assuming that it's a comma separated string, then I'd do something like this:

$polyPoints = $row['polyPoints'];
// $polyPoints now has this value:
// 50.37349614430351, -2.0654296875000106,51.56341232867588, 2.4609375,53.514184520771124, -3.427734375000007,50.37349614430351, -2.0654296875000106

$polyPoints = explode(',', $polyPoints);
// $polyPoints now has this value:
// Array (
//     [0] => 50.37349614430351
//     [1] => -2.0654296875000106
//     [2] => 51.56341232867588
//     [3] => 2.4609375
//     [4] => 53.514184520771124
//     [5] => -3.427734375000007
//     [6] => 50.37349614430351
//     [7] => -2.0654296875000106


$JSON = json_encode($polyPoints);
// $JSON now has this value:
// ["50.37349614430351"," -2.0654296875000106","51.56341232867588"," 2.4609375","53.514184520771124"," -3.427734375000007","50.37349614430351"," -2.0654296875000106"]

// Now just echo the value of $JSON into a new Javascript variable:
echo '<script language="Javascript"><!-- // --><![CDATA[
    var polyPoints = ' . $JSON . '

var polygon = new VEShape(VEShapeType.Polygon, polyPoints);
polygon.HideIcon();
map.AddShape(polygon);
// ]]></script>';

And there you have it. The javascript variable "polypoints" will be a javascript array which you can use to get the items like:
polyPoints[?] where ? will be a number between 0 and 7.

[djalecc]

Hi

Thanks for quick response...

I'm using PHP 4, can it still be done another way?

🙂

[djalecc]

Hi

In fact, to make things work [ I've just found out ]

The Var must be returned like this in Javascript.

var points = [
new VELatLong(50.37349614430351, -2.0654296875000106),
new VELatLong(51.56341232867588, 2.4609375),
new VELatLong(53.514184520771124, -3.427734375000007),
new VELatLong(50.37349614430351, -2.0654296875000106)
];

Things I notice are...

The first and last lines are always the same [ to close the polygon ]
The last 'new VELatLong() does not have a , to continue...

So I need to turn

$polyPoints="50.37349614430351, -2.0654296875000106,51.56341232867588, 2.4609375,53.514184520771124, -3.427734375000007,50.37349614430351, -2.0654296875000106";

in to...

var points = [
new VELatLong(50.37349614430351, -2.0654296875000106),
new VELatLong(51.56341232867588, 2.4609375),
new VELatLong(53.514184520771124, -3.427734375000007),
new VELatLong(50.37349614430351, -2.0654296875000106)
];

remembering there could be any number of points held in $row[polyPoints];

😕

[bpat1434]

for($i=0; $i<count($polyPoints); $i++)
{
    $js .= 'new VELatLong('.$polyPoints[$i].', '.$polyPoints[++$i].'),';
}

$js = substr($js, 0, -1); // remove the last ","

$output = 'var points = [' . $js . '];';

echo $output;

Something like that?