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Author: | Jeff McKenna |
---|---|
Contact: | jmckenna at gatewaygeomatics.com |
Revision: | $Revision: 12506 $ |
Date: | $Date: 2011-08-29 14:26:49 +0200 (Mon, 29 Aug 2011) $ |
Table of Contents
The following functionality was added to MapServer 4.4.0 as a part of a project sponsored by the Information-technology Promotion Agency (IPA), in Japan. Project members included: Venkatesh Raghavan, Masumoto Shinji, Nonogaki Susumu, Nemoto Tatsuya, Hirai Naoki (Osaka City University, Japan), Mario Basa, Hagiwara Akira, Niwa Makoto, Mori Toru (Orkney Inc., Japan), and Hattori Norihiro (E-Solution Service, Inc., Japan).
The mapfile LABEL object’s parameter named ENCODING can be used to convert strings from its original encoding system into one that can be understood by the True Type Fonts. The ENCODING parameter accepts the encoding name as its parameter.
MapServer uses GNU’s libiconv library ( http://www.gnu.org/software/libiconv/ ) to deal with encodings. The libiconv web site has a list of supported encodings. One can also use the “iconv -l” command on a system with libiconv installed to get the complete list of supported encodings on that specific system.
So, theoretically, every string with an encoding system supported by libiconv can be displayed as labels in MapServer as long as it has a matching font-set.
Execute ‘’mapserv -v’ at the commandline, and verify that your MapServer version >= 4.4.0 and it includes ‘’SUPPORTS=ICONV’‘, such as:
> mapserv -v
MapServer version 5.6.5 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG
OUTPUT=WBMP OUTPUT=PDF OUTPUT=SWF OUTPUT=SVG SUPPORTS=PROJ
SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=ICONV SUPPORTS=FRIBIDI
SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER
SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER
SUPPORTS=FASTCGI SUPPORTS=THREADS SUPPORTS=GEOS SUPPORTS=RGBA_PNG
SUPPORTS=TILECACHE INPUT=JPEG INPUT=POSTGIS INPUT=OGR INPUT=GDAL
INPUT=SHAPEFILE
Since MapServer uses the libiconv library to handle encodings, you can check the list of supported encodings here: http://www.gnu.org/software/libiconv/
Unix users can also use the iconv -l command on a system with libiconv installed to get the complete list of supported encodings on that specific system.
Now you can simply add the ENCODING parameter to your mapfile LAYER object, such as:
MAP
...
LAYER
...
CLASS
...
LABEL
...
ENCODING "SHIFT_JIS"
END
END
END
END
One of the benefits of having an “ENCODING” parameter within the LABEL object is that different LAYERS with different encoding systems can be combined together and display labels within a single map. For example, labels from a Layer using Shapefile as it source which contains attributes in SHIFT-JIS can be combined with a Layer from a PostGIS database server with EUC-JP attributes. A sample Mapfile can look like this:
LAYER
NAME "chimei"
DATA chimei
STATUS DEFAULT
TYPE POINT
LABELITEM "NAMAE"
CLASS
NAME "CHIMEI"
STYLE
COLOR 10 100 100
END
LABEL
TYPE TRUETYPE
FONT kochi-gothic
COLOR 220 20 20
SIZE 10
POSITION CL
PARTIALS FALSE
BUFFER 0
ENCODING SHIFT_JIS
END
END
END
LAYER
NAME "chimeipg"
CONNECTION "user=username password=password dbname=gis host=localhost port=5432"
CONNECTIONTYPE postgis
DATA "the_geom from chimei"
STATUS DEFAULT
TYPE POINT
LABELITEM "NAMAE"
CLASS
NAME "CHIMEI PG"
STYLE
COLOR 10 100 100
END
LABEL
TYPE TRUETYPE
FONT kochi-mincho
COLOR 20 220 20
SIZE 10
POSITION CL
PARTIALS FALSE
BUFFER 0
ENCODING EUC-JP
END
END
END
For PHP Mapscript, the Encoding parameter is included in the LabelObj Class, so that the encoding parameter of a layer can be modified such as:
// Loading the php_mapscript library
dl("php_mapscript.so");
// Loading the map file
$map = ms_newMapObj("example.map");
// get the desired layer
$layer = $map->getLayerByName("chimei");
// get the layer's class object
$class = $layer->getClass(0);
// get the class object's label object
$clabel= $class->label;
// get encoding parameter
$encode_str = $clabel->encoding;
print "Encoding = ".$encode_str."\n";
// set encoding parameter
$clabel->set("encoding","UTF-8");
Note
During initial implementation, this functionality was tested using the different Japanese encoding systems: Shift-JIS, EUC-JP, UTF-8, as well as Thai’s TIS-620 encoding system.
Examples of encodings for the Latin alphabet supported by libiconv are: ISO-8859-1 (Latin alphabet No. 1 - also known as LATIN-1 - western European languages), ISO-8859-2 (Latin alphabet No. 2 - also known as LATIN-2 - eastern European languages), CP1252 (Microsoft Windows Latin alphabet encoding - English and some other Western languages).