Changes between Version 1 and Version 2 of CodeSamples/PHP/InitialMapView

Timestamp:

09/02/08 05:04:42 (17 years ago)

Author:

gingerbbm

Comment:

Added the main bulk.

CodeSamples/PHP/InitialMapView

@@ -4 +4 @@
 
 == Dynamically setting initial map view and scale ==
-To do...
+The following script allows us to set the initial ''x'', ''y'' and ''scale'' attributes of a map using the MapGuide Ajax Viewer. It expects the values to be passed to the script as querystring parameters, e.g.
+
+  http://localhost/mapguide/set_intial_view.php?x=507700&y=186000&scale=400000
+
+It works by taking a copy of the ''WebLayout'' stored in the ''Library repository'' and changing the <CenterX/>, <CenterY/> and <Scale/> elements. The updated XML is written into the ''Session'' and is used as the target when the page is ultimately redirected.
+
+
+== Things to note ==
+ - A side-effect of the code is that it facilitates anonymous connections
+ - The parameter-checking could be made a little more robust *cough*
+ - The ''$wl'' variable should be changed to reflect the relevant ''WebLayout'' identifier
+
+
+== The code ==
+{{{
+#!php
+<?php
+
+//
+// Vital includes.
+//
+$viewerDir = "mapviewerphp\\";
+include $viewerDir . "constants.php";
+include $viewerDir . "common.php";
+
+//
+// Check and get the required parameters.
+//
+if (!isset($_REQUEST["x"]) || !isset($_REQUEST["y"]) || !isset($_REQUEST["scale"])) {
+        echo "<Error>One or more of the required arguments is missing.</Error>";
+        exit;
+}
+
+$x = $_REQUEST["x"];
+$y = $_REQUEST["y"];
+$scale = $_REQUEST["scale"];
+
+//
+// Usual initialisation step.
+//
+InitializeWebTier();
+
+//
+// Obtain a new session ID for this anonymous user, use it to set up
+// a new site connection and use that to create a resource service.
+//
+$site = new MgSite();
+$site->Open(new MgUserInformation("Anonymous", ""));
+
+$sessionId = $site->CreateSession();
+
+$siteConnection = new MgSiteConnection();
+$siteConnection->Open(new MgUserInformation($sessionId));
+
+$resourceService = $siteConnection->CreateService(MgServiceType::ResourceService);
+
+//
+// Read the web layout into an XML DOM document object.
+//
+$wl = "Library://WebPID/WebPID_SDF_Static.WebLayout"; // TODO Constant!
+$wlResourceId = new MgResourceIdentifier($wl);
+$wlReader = $resourceService->GetResourceContent($wlResourceId);
+$wlXml = $wlReader->ToString();
+$wlDomDoc = DOMDocument::loadXML($wlXml); 
+
+//
+// Now, update the initial x, y and scale values with the desired values.
+//
+$nodeCenterX = $wlDomDoc->getElementsByTagName("CenterX")->item(0);
+$nodeCenterX->nodeValue = "$x";
+
+$nodeCenterY = $wlDomDoc->getElementsByTagName("CenterY")->item(0);
+$nodeCenterY->nodeValue = "$y";
+
+$nodeScale = $wlDomDoc->getElementsByTagName("Scale")->item(0);
+$nodeScale->nodeValue = "$scale";
+
+//
+// Prepare the updated XML to be written out to the session.
+//
+$updatedXml = $wlDomDoc->saveXML();
+$byteSource = new MgByteSource($updatedXml, strlen($updatedXml));
+
+//
+// Create a web layout in the session to hold the updated version
+// from the library.
+//
+$sessionMapName = $wlResourceId->GetName();
+$sessionWebLayout = "Session:$sessionId//$sessionMapName.WebLayout";
+$sessionResourceId = new MgResourceIdentifier($sessionWebLayout);
+
+//
+// Write the updated web layout to the session.
+//
+$resourceService->SetResource($sessionResourceId, $byteSource->GetReader(), null);
+
+//
+// Redirect to the Ajax viewer pointing at the map at the desired coordinates.
+//
+$redirectTo = "mapguide/mapviewerajax/?SESSION=$sessionId&WEBLAYOUT=$sessionWebLayout";
+$host = $_SERVER["HTTP_HOST"];
+$url = "http://$host/$redirectTo";
+
+//
+// Redirect!
+//
+header("Location: $url");
+exit;
+
+?>
+}}}
+
+
+== See also ==
+To reposition a MapGuide map at a given ''x'', ''y'' and ''scale'' using JavaScript, take a look at the ZoomToView() API function.
+