The digitizing functions in the Viewer API provide us with the digitized coordinates on the client, but we usually need to pass them to a server side script. This can be done with the Viewer API, using the Submit() method of the formFrame.
function OnLineDigitized(line) {
// Send the Javascript variables to 'draw_line.php',
// via the form frame
var params = new Array("x0", line.Point(0).X,
"y0", line.Point(0).Y,
"x1", line.Point(1).X,
"y1", line.Point(1).Y,
"SESSION", "<?= $sessionId ?>",
"MAPNAME", "<?= $mapName ?>");
parent.parent.formFrame.Submit(
"/mapguide/samplesphp/digitizing_features/draw_line.php",
params, "scriptFrame");
}
This submits the coordinates to the server-side function to draw the line. It uses the hidden scriptFrame so the page output is not visible.