Reader Directives

The following directives are processed by the MGE reader. The suffixes shown will be prefixed by the current <ReaderKeyword> in the mapping file. By default, the <ReaderKeyword> for the MGE reader is MGE.

Note: Please see the Bentley MicroStation Design Reader/Writer for other applicable directives.

DATASET

Required/Optional: Required

Contains the folder name of the input MGE files.

SERVER_TYPE

Required/Optional: Required

Contains the server type for the input data.

SERVER_NAME

Required/Optional: Required

Contains the server name for the input data.

USER_NAME

Required/Optional: Optional

Contains the user name for the database. May be required by the database being used.

Workbench Parameter: Database Username

PASSWORD

Required/Optional: Optional

Contains the password for the database. May be required by the database being used.

Workbench Parameter: Database Password

DATABASE_NAME

Required/Optional: Optional

Contains the database name. May be required by the database being used.

DEF

Workbench Parameter

Required

This directive must be used to define a feature before elements of that feature may be read. It allows complete specification of a MGE feature. The definition of a feature consists of:

  • A name for the feature.
  • A set of database attributes associated with each element attached to the feature. All database attributes of a given feature are stored in a single table; elements attached to that feature contain linkages into this attribute table.
  • A set of properties which apply to all map objects belonging to that feature. (These properties, described in greater detail below, define the graphic specifications applied to elements attached to the feature, as well as specifying the feature’s feature code, category, and other feature-specific attributes.)

The syntax for the definition line is:

<ReaderKeyword>_DEF “<featureName>” \
[<attrName> <attrType>]* \
[<featPropertyName> “<featPropertyValue>”]*

The feature name must follow the conventions for MGE feature names. The letter case of alphabetic characters in the names is insignificant, as all names are converted to lowercase for internal use by the MGE Reader.

There may be zero or more attributes associated with a feature. Like feature names, the case of attribute names is insignificant. (Attribute names are conventionally specified in lowercase to more easily distinguish them from the type properties.) The following table shows the supported attribute types:

Field Type

Description

char(<width>)

Character fields store fixed length strings. The width parameter controls the maximum of characters that can be stored by the field. No padding is required for strings which are shorter than this width.

date

Date fields store dates as character strings with the format YYYYMMDD.

number(<width>,<decimals>)

Number fields store single and double precision floating point values. The width parameter is the total number of characters allocated to the field, including the decimal point. The decimals parameter controls the precision of the data, and is the number of digits to the right of the decimal.

logical

Logical fields store TRUE/FALSE data. Data read or written from/to such fields must always have a value of either true or false.

The MGE reader only requires the specification of those attributes which are of interest to the translation process; there is no need to mention any attributes which are not used. Further, every attribute which is specified in the mapping file is verified against those associated with the feature being defined, to ensure that it exists and that its type is compatible.

There are a number of properties that may be specified to define the feature of interest. Every specified property must agree with the existing MGE feature, or an error will result. No property specifications are required when reading from a MGE project; however, in order for feature attributes not belonging to the design file to be written, a GG_ATTR_TABLE needs to be defined (the default table name is the feature name).

UNITS

Required/Optional

Optional

This directive controls the conversion between UORs in the design file and FME coordinates. There are three possibilities, outlined in the table below. If no UNITS directive is specified, then GG_MASTER_UNITS is the default.

GG_UNITS Value Description

GG_MASTER_UNITS

The UORs read from the design file will be converted into master units, according to the conversion factor defined in MicroStation’s terminal control block (TCB), before being stored in an FME feature. This is the default.

GG_SUB_UNITS

The UORs read from the design file will be converted into subunits, according to the conversion factor defined in MicroStation’s TCB, before being stored in an FME feature.

GG_UORS

The UORs read from the design file will be stored directly in an FME feature, with no conversion.

FEATURE_TABLE_NAME

This directive identifies the name of the feature table. Use this directive only if you have a feature table with the name other than feature.

Workbench Parameter

Feature table name

CATEGORY_TABLE_NAME

This directive identifies the name of the feature table. Use this directive only if you have a category table with the name other than category.

Workbench Parameter

Category table name