CLASS

BACKGROUNDCOLOR [r] [g] [b] - deprecated

Deprecated since version 6.0: Use CLASS STYLEs.

COLOR [r] [g] [b]

Deprecated since version 6.0: Use CLASS STYLEs.

DEBUG [on|off]

Enables debugging of the class object. Verbose output is generated and sent to the standard error output (STDERR) or the MapServer logfile if one is set using the LOG parameter in the WEB object.

See also

MS RFC 28: Redesign of LOG/DEBUG output mechanisms

EXPRESSION [string]

Four types of expressions are now supported to define which class a feature belongs to: String comparisons, regular expressions, logical expressions, and string functions (see Expressions). If no expression is given, then all features are said to belong to this class.

• String comparisons are case sensitive and are the fastest to evaluate. No special delimiters are necessary although strings must be quoted if they contain special characters. (As a matter of good habit, it is recommended that you quote all strings). The attribute to use for comparison is defined in the LAYER CLASSITEM parameter.

• Regular expression are limited using slashes (/regex/). The attribute to use for comparison is defined in the LAYER CLASSITEM parameter.

• Logical expressions allow the building of fairly complex tests based on one or more attributes and therefore are only available with shapefiles. Logical expressions are delimited by parentheses “(expression)”. Attribute names are delimited by square brackets “[ATTRIBUTE]”. Attribute names are case sensitive and must match the items in the shapefile. For example:

  EXPRESSION ([POPULATION] > 50000 AND '[LANGUAGE]' eq 'FRENCH')
  

  The following logical operators are supported: =, >, <, <=, >=, =, or, and, lt, gt, ge, le, eq, ne, in, ~, ~*. As one might expect, this level of complexity is slower to process.

  • One string function exists: length(). It computes the length of a string:

    EXPRESSION (length('[NAME_E]') < 8)
    

String comparisons and regular expressions work from the classitem defined at the layer level. You may mix expression types within the different classes of a layer.

GROUP [string]

Allows for grouping of classes. It is only used when a CLASSGROUP at the LAYER level is set. If the CLASSGROUP parameter is set, only classes that have the same group name would be considered at rendering time. An example of a layer with grouped classes might contain:

LAYER
  ...
  CLASSGROUP "group1"
  ...
  CLASS
    NAME "name1"
    GROUP "group1"
    ...
  END
  CLASS
    NAME "name2"
    GROUP "group2"
    ...
  END
  CLASS
    NAME "name3"
    GROUP "group1"
    ...
  END
  ...
END # layer

KEYIMAGE [filename]

Full filename of the legend image for the CLASS. This image is used when building a legend (or requesting a legend icon via MapScript or the CGI application).

LABEL

Signals the start of a LABEL object. A class can contain multiple labels (since MapServer 6.2).

LEADER

Signals the start of a LEADER object. Use this along with a LABEL object to create label leader lines.

New in version 6.2.

MAXSCALEDENOM [double]

Minimum scale at which this CLASS is drawn. Scale is given as the denominator of the actual scale fraction, for example for a map at a scale of 1:24,000 use 24000. Implemented in MapServer 5.0, to replace the deprecated MAXSCALE parameter.

See also

Map Scale

MAXSIZE [integer]

Deprecated since version 6.0: Use CLASS STYLEs.

MINSCALEDENOM [double]

Maximum scale at which this CLASS is drawn. Scale is given as the denominator of the actual scale fraction, for example for a map at a scale of 1:24,000 use 24000. Implemented in MapServer 5.0, to replace the deprecated MINSCALE parameter.

See also

Map Scale

MINSIZE [integer]

Deprecated since version 6.0: Use CLASS STYLEs.

NAME [string]

Name to use in legends for this class. If not set class won’t show up in legend.

OUTLINECOLOR [r] [g] [b]

Deprecated since version 6.0: Use CLASS STYLEs.

SIZE [integer]

Deprecated since version 6.0: Use CLASS STYLEs.

STATUS [on|off]

Sets the current display status of the class. Default turns the class on.

STYLE

Signals the start of a STYLE object. A class can contain multiple styles. Multiple styles can be used create complex symbols (by overlay/stacking). See Cartographical Symbol Construction with MapServer for more information on advanced symbol construction.

SYMBOL [integer|string|filename]

Deprecated since version 6.0: Use CLASS STYLEs.

TEMPLATE [filename]

Template file or URL to use in presenting query results to the user. See Templating for more info.

TEXT [string|expression]

Text to label features in this class with. This overrides values obtained from the LAYER LABELITEM. The string can contain references to feature attributes. This allows you to concatenate multiple attributes into a single label. You can for example concatenate the attributes FIRSTNAME and LASTNAME like this:

TEXT '[FIRSTNAME] [LASTNAME]'

More advanced Expressions can be used to specify the labels. Since version 6.0, there are functions available for formatting numbers:

TEXT ("Area is: " + tostring([area],"%.2f"))

VALIDATION

Signals the start of a VALIDATION block.

As of MapServer 5.4.0, VALIDATION blocks are the preferred mechanism for specifying validation patterns for CGI param runtime substitutions. See Run-time Substitution.