Changes between Initial Version and Version 1 of PerlMapScriptExamples35ex16

Timestamp:

Jan 29, 2009, 7:08:52 AM (15 years ago)

Author:

jmckenna

Comment:

--

PerlMapScriptExamples35ex16

@@ +1 @@
+= Fetchmap.pl =
+
+Fetchmap.pl is CGI backend wrapper interface that uses mapscript. This example will accept the following inputs: LAT/LON, mapfile, mapext (extents), mapsize input arguments via URL and generates map images. Demonstrates mapserv error handling, establishing and overriding parameter defaults, URL/CGI inputs and showing a few old methods for different version of mapserv. This example shows some simplistic functionality of perl mapscript in a CGI setting. These wese designed to emulate a few inputs of the Tiger Map Server.
+
+Here are a couple of URL examples:
+
+Miami, FL - http://www.siliconmapping.com/mapper/cgi-bin/fetchmap.pl?lat=25.561&lon=-80.462&mapsize=300+210&mapext=1642750+2865665+1816633+2987024 with URL specifying lat/lon, size and extents
+
+Default US Map - http://www.siliconmapping.com/mapper/cgi-bin/fetchmap.pl with default lat/lon, size and extents
+----
+{{{
+#!perl
+#!/usr/bin/perl
+
+use CGI;   # prerequisite package/module
+use mapscript;
+
+$ENV{MS_ERRORFILE}="/var/log/mapserver";
+$mapfile = $query->param('map') or $mapfile = "/home/httpd/html/mapper/tiger35.map";
+
+# create new CGI object
+$query = new CGI;
+
+@extent = split(' ', $query->param('mapext')) or
+        @extent = split('\,',"-3300000,2200000,3400000,7200000"); # the default
+
+die $mapscript::ms_error->{code}.": ".$mapscript::ms_error->{message} unless $map = new mapObj($mapfile);
+
+if (defined($query->param(mapsize))) {
+   ($map->{width},$map->{height}) = split(' ', $query->param('mapsize'));
+} else {
+   $map->{width} = 640; $map->{height} = 480;  # default size
+}
+
+
+$map->{extent}->{minx} = $extent[0];
+$map->{extent}->{miny} = $extent[1];
+$map->{extent}->{maxx} = $extent[2];
+$map->{extent}->{maxy} = $extent[3];
+
+
+$img = $map->draw() or LogDie "Unable to render map.", $mapscript::ms_error->{message};
+
+
+print $query->header('image/gif');
+
+# mapserv 3.2 method
+# mapscript::msSaveImage($img, undef, 0,0);
+
+# mapserv 3.5 method
+mapscript::msSaveImage($img,undef,$mapscript::MS_GIF,$map->{transparent},$map->{interlace},undef);
+
+
+#  LogDie is a routine that appends a user define "MyErrorMessage"
+#  to the tail end of the mapserver log
+#
+sub LogDie {
+   $msg = shift(@_);
+   open(LOG,$ENV{MS_ERRORLOG});
+   print LOG $msg;
+   close(LOG);
+   exit;
+
+}
+}}}
+----
+back to PerlMapScript