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--- doc:appunti:linux:sa:debian_11_12_mapserver_upgrade [2023/11/23 16:52] – [CONFIG:MAPS aliases] niccolo
+++ doc:appunti:linux:sa:debian_11_12_mapserver_upgrade [2023/11/23 17:11] (current) – [MAP:TRANSPARENT not longer valid] niccolo
@@ Line 43: / Line 43: @@
 </code>
-==== MAP:TRANSPARENT not longer valid ====
+===== MAP:TRANSPARENT not longer valid =====
-In MapServer 8 mapfiles it is not longer accepted the TRANSPARENT identifier inside the MAP object, you have to move it into the OUTPUTFORMAT object.
+In MapServer 8 mapfiles the **TRANSPARENT** identifier is not longer accepted inside the MAP object, you have to move it into the **OUTPUTFORMAT** object; something like this:
+<file>
+  OUTPUTFORMAT
+    NAME agg_png
+    DRIVER "AGG/PNG"
+    MIMETYPE "image/png"
+    IMAGEMODE RGBA
+    EXTENSION "png"
+    TRANSPARENT ON
+  END
+</file>
+===== Name change of CGI parameters =====
+One of the biggest problem of the upgrade is the change of the name of some CGI parameters; notably the **map_size** option is not longer supported.
+I had web application based on OpenLayers 2.11, which included a MapServer bitmap layer. The JavaScript code automatically generates the request URL, something like this (parameters are split on different lines for readability):
+<code>
+/cgi-bin/mapserv?map=/usr/local/lib/mapserver/mie_strade.map
+    &format=image%2Fpng
+    &mode=map
+    &map_imagetype=png
+    &mapext=1235758.1079621+5432310.5814201+1242666.1043925+5443174.1940635
+    &imgext=1235758.1079621+5432310.5814201+1242666.1043925+5443174.1940635
+    &map_size=1446+2274
+    &imgx=723
+    &imgy=1137
+    &imgxy=1446+2274
+</code>
+Unfortunately the **map_size** option is not longer accepted and the resulting PNG image has the default size declared into the MAP:SIZE object of the mapfile, instead of the requested 1446x2274 pixels. This causes a **totally distorted map** image into the web application!
+This problem cannot be easily fixed, because the URL options are hard-coded into the OpenLayers code. So I had to replace all the OpenLayers 2.x code with the current **OpenLayers 8.x**, which required a total refactory of the code.