Mapfile configuration¶
As mentioned on the index page (Administrator Guide) the application administrator manages the application through the database and via the application’s MapServer mapfile.
The application’s mapfile is where WMS and WFS layers are defined. WMS is used
for the map (WMS GetMap
), and for the point query
feature (WMS
GetFeatureInfo
). WFS is used for the box query
and query builder
features (WFS GetFeature
).
The application’s mapfile is located in the mapserver
directory, it is
commonly named mapserver.map.mako
.
Note
The application’s mapfile is a .mako
file because it contains variables.
These variables are substituted when the make
build command is
executed.
This section describes how to make layers printable and/or queryable and/or private (a.k.a restricted).
Warning
Please note that, because of c2cgeoportal’s caching system, each time you update the mapfile configuration, you have to reload apache.
(on debian system, you can do: sudo /usr/sbin/apache2ctl graceful
).
Print¶
MapFish Print performs single tile requests to the WMS server. For that reason we
need to use a relatively large value for the MAXSIZE
parameter (of the
MAP
section); 5000 for example.
MapFish Print also supports map rotations. This implies specific requirements:
The
MAP
and all theLAYER``s should have a ``PROJECTION
. For example:PROJECTION "init=epsg:21781" END
When rotating the map (with a non-zero value for
ANGLE
) there are important things to be aware of. Make sure to read the notes for theANGLE
parameter on http://mapserver.org/mapfile/map.html.
MapFish Print uses a resolution of 254 dpi (instead of 72 dpi as used for the
web application on the screen). Using LAYER
/SYMBOLSCALEDENOM
is
therefore not recommended. LABEL
/MINSIZE
and LABEL
/MAXSIZE
should be used when necessary only, as these parameters do not take the MAP
resolution into account.
WFS GetFeature¶
Layers involved in the box query
and query builder
features should
support WFS GetFeature. To support WFS GetFeature a LAYER
should define
a template:
TEMPLATE "fooOnlyForWFSGetFeature"
This is a fake template, but this is required by the querier and for the filter.
The LAYER
should also define metadata, with a METADATA
section. For
example:
"gml_include_items" "all"
"gml_types" "auto"
"gml_featureid" "id"
"wfs_enable_request" "*"
gml_include_items
This is a comma-delimited list of attribute names, it specifies the list of attributes that should be returned in GML responses.all
means that all the attributes of the layer should be returned.
gml_types
Set this toauto
. This means that the layer’s field type information is obtained from the input feature driver (OGC). If the type is not well interpreted (notably if you have a wrong operator within your filter), you can define manually your attribute type with"gml_<attribute>_type" "<type>"
where<type>
is one of these:Integer
,Long
,Real
,Character
,Date
orBoolean
.
gml_featureid
References the name of layer’s primary key column. Setting this is mandatory forGetFeature
request includingogc:FeatureId
filters. Always set it. (This is required for the JavaScript API.)
wfs_enable_request
Space separated list of requests to enable. Use*
.
Warning
The geometry columns of layers involved in box query
should have the
same name. By default the WFS GetFeature CGXP plugin
(cgxp_wfsgetfeature
) assumes the name is geom
, but the plugin
can be configured to use a different name.
In contrast to WMS GetFeatureInfo, WFS GetFeature supports point query
as
well as box query
(i.e. drawing a box and getting information about the
features with that box). However, it is to be noted that WFS GetFeature may
return features that are not visible at the current resolution of the map.
This is because a limitation in MapServer, where MINSCALE
/MAXSCALE
values defined in the layer’s classes (CLASS
) have no effect.
WMS GetFeatureInfo¶
Layers involved in the point query
feature should support WMS
GetFeatureInfo.
To support WMS GetFeatureInfo a LAYER
should define a template:
TEMPLATE fooOnlyForWMSGetFeatureInfo
As for WFS GetFeature, this is a fake template, but it is required.
The gml_include_items
, gml_<geometry name>_type
and gml_geometries
METADATA variables should also be defined in the LAYER
. For
example:
"gml_include_items" "all"
"gml_geometries" "geom"
"gml_geom_type" "polygon"
gml_include_items
See above.
gml_geometries
This is a string specifying the name used for geometry elements in GetFeatureInfo (GML) responses. This property, andgml_<name>_type
, should be set for the GetFeatureInfo responses to include the features’ geometries instead of bboxes.
gml_<geometry name>_type
This specifies the type of a geometry column. Specifying this property is necessary if geometries, instead of bboxes, should be returned in GetFeatureInfo (GML) responses.<geometry name>
should be replaced the string set with thegml_geometries
. For example, ifgeom_geometries
is set tothe_geom
thengml_the_geom_type
should be used. The possible values arepoint
,multipoint
,line
,multiline
,polygon
,multipolygon
, if you do not set the right type for multi geometries only the first will be visible on the map. See also gml_<geometry name>_type.
See the WMS Server MapFile Documentation for more detail.
Restricted layer¶
The restricted layers work only with PostgreSQL data. All layers defined as restricted in the mapfile should be defined as well in the admin interface and vice versa.
With a RestrictionArea area¶
A RestrictionArea is used to restrict the layer displaying to a given area.
This area is specified in the administration interface while defining the
RestrictionArea
element.
Warning
Using a restriction area on a big layer or defining a very complex area may slow down the application.
To define a restricted layer in the Mapfile, the DATA
property of the
LAYER
should look like this:
DATA "the_geom FROM
(SELECT
geo.*
FROM
<schema>.<table> AS geo
WHERE
ST_Contains(
(${mapfile_data_subselect} '<layername>'),
ST_SetSRID(geo.<the_geom>, 21781)
)
) as foo using unique id using srid=21781"
<schema>
, <table>
, <layername>
and <the_geom>
need to be
replaced as appropriate. <table>
is the name of the PostGIS table including
the geographic data for this layer. <the_geom>
is the name of the table’s
geometry column. <schema>
is the name of the schema including the table.
<layer_name>
can be either the layer NAME or the layer GROUP, depending on
what is configured in the admin interface for the layer.
Note
The DATA example above is developed on several lines to make it easily readable in this documentation. However please note that MapServer requires that this directive is contained on a single line.
Warning
In some cases you can have geometries that overlap the restriction area. Theses features will not be displayed as they are not in the area (ie not contained). st_intersects or other operator could be used instead of the st_contains operator.
The ${mapfile_data_subselect}
variable is defined in the CONST_vars.yaml
configuration file. Its goal is to simplify the writing of the mapfile.
It is defined as follows:
SELECT
ST_Collect(ra.area)
FROM
main.restrictionarea AS ra,
main.role_restrictionarea AS rra,
main.layer_restrictionarea AS lra,
main.treeitem AS la
WHERE
rra.role_id = %role_id%
AND
rra.restrictionarea_id = ra.id
AND
lra.restrictionarea_id = ra.id
AND
lra.layer_id = la.id
AND
la.name =
Without restriction on the RestrictionArea area¶
If we do not need to restrict on an area, we can use the following
DATA
property of the LAYER
:
DATA "the_geom FROM (
SELECT
geo.*
FROM
<schema>.<table> AS geo
WHERE (
%role_id% IN (
${mapfile_data_noarea_subselect} '<layername>'
)
)
) AS foo USING UNIQUE id USING srid=21781"
Then you do not need to define an area in the admin interface.
The ${mapfile_data_noarea_subselect}
is defined as follows:
SELECT
rra.role_id
FROM
main.restrictionarea AS ra,
main.role_restrictionarea AS rra,
main.layer_restrictionarea AS lra,
main.treeitem AS la
WHERE
rra.restrictionarea_id = ra.id
AND
lra.restrictionarea_id = ra.id
AND
lra.layer_id = la.id
AND
la.name =
Metadata and filename¶
It is required to have the following in the VALIDATION
section of
the LAYER
:
${mapserver_layer_validation}
This variable is defined in the CONST_vars.yaml
configuration file
as follows:
mapserver_layer_validation =
"default_role_id" "-1"
"role_id" "^-?[0-9]*$$"
The mapfile should be a .map.mako
file, for the variable to be
substituted at make execution time.
Variable Substitution¶
It is possible to adapt some values in the mapfile according to the user’s role by using variable substitution, for instance to hide some layer objects attributes. The list of parameters that support variable substitution is available here.
To define variables, edit the matching MAP
/LAYER
/VALIDATION
section in the MapFile and add:
"default_s_<variable>" "<default_value>"
"s_<variable>" "<validation_pattern>"
The validation_pattern
is a regular expression used to validate the
argument. For example, if you only want lowercase characters and commas,
use ^[a-z,]*$
.
Now in LAYER
place %s_<variable>%
where you want to
insert the variable value, but not at the start of a line (to avoid escape issues).
Then in the administration interface, create a functionality
named
mapserver_substitution
with the value: <variable>=<value>
.
Please note that we cannot use substitution in the METADATA
values.
As a result, if you would like to adapt the list of attributes returned in a
WFS GetFeature or WMS GetFeatureInfo request, you have to adapt the columns
listed in the DATA
section. For instance:
LAYER
...
DATA "geom FROM (SELECT t.geom, t.type, t.gid, %s_columns% FROM geodata.table as t) AS foo using unique gid using SRID=21781"
METADATA
...
"gml_exclude_items" "type,gid"
"gml_include_items" "all"
END
VALIDATION
"default_s_columns" "t.name"
"s_columns" "^[a-z,._]*$$"
END
CLASS
EXPRESSION ([type]=1)
...
END
...
END
Then add a mapserver_substitution
functionality in the administration
interface with for instance the following value for the given role:
columns=t.private
.
Note
You can also use variable substitution for the role_id
and user_id
,
but beware that these attributes are not available for cached queries like:
GetCapabilities
, GetLegendGraphic
, DescribeFeatureType
.
Legend¶
Legend text configuration¶
MapServer allows different forms of legends.
Legend with legend text (normal configuration, f.e.
[ o ] Placemark
):CLASS NAME "Placemark" STYLE ... END END
Legend without legend text (f.e.
[ o ]
, often used if there is one single class in the layer ):CLASS NAME " " STYLE ... END END
You can set the
legend rule
in the admin interface to%20
, if you want to show the legend icon in the layer treeNo legend (do not set any
NAME
in theCLASS
):CLASS STYLE ... END END
Performance improvement¶
Adding an EXTENT
parameter to the LAYER
section may significantly improve the performances
because it saves MapServer from computing the extent of all layer features.
Prepare raster files¶
To achieve good performance, you should have tiled files with overview, and ideally a tileindex, you can achieve this with these steps:
Convert your rasters in tiled GeoTIFF:
gdal_translate -of GTiff -co "TILED=YES" -co "TFW=YES" <filename_in.tif> <filename_out.tif>
Then build overviews for your rasters:
gdaladdo -r average filename.tif 2 4 8 16
You can generate a shapefile indexing all your rasters:
gdaltindex filename_index.shp raster/*.tif
Note about ECW¶
In general using ECW is not recommended, as MapServer often generates broken images and has memory leaks with ECW. See this MapServer ticket for example.
If you still want to use it, then replace SetHandler fcgid-script
by SetHandler cgi-script
in the apache/mapserver.conf.mako
file. But note that this affects performance.