Conditional expression

A part of a script that is only executed if certain conditions are satisfied. For example, if a script that deletes all lines shorter than a specified size is required, use a conditional expression to make sure that only those short lines are deleted.

Loop

A part of a script that is repeated until some final condition occurs. Often a variable is used to count how many times the loop should be repeated. For example, to analyze all vertices in a line string, use a variable to keep track of how many times the loop has been executed and how many vertices have been handled.

Script

Analyzes or updates the graphical elements in a design file or the attributes stored in a database. A script is stored in a text file with the .GSF extension. A script consists of two parts: a SETUP filter defines which graphical elements the script will handle and the VALIDATE rules contains the rules that analyze or update the graphical elements.

SETUP filter

Defines which graphical elements should be handled by a script. The setup filter can filter out elements based on their symbology, element type, design file name, feature or database linkage.

Stroke

The curved element is transformed into a linear element. The stroke tolerance defined by the STROKE parameter in the settings box, defines the maximum allowed gap between the stroked linear element and the original element. Visualize trying to digitize a curve using only line strings. When using only a few vertices in the line string, the approximation to the original curve will be very crude because the gap is rather large.

Spatial analysis

Using several vertices, the gap will be much smaller and the approximation will be very close to the original curve. When doing spatial analyses, analyze the relationship between several graphical elements. For example, if one element is inside, outside or near another element.

SQL

Structured Query Language. A standard language used for querying a database.

GSF

Scripts are stored in files with the extension GSF. The script files are simple text files.

VALIDATE rules

The VALIDATE rules are the most important part of the script; this is where the actual analysis, updating takes place.

Variables

Used in a script to store information about a graphical element or the associated database attributes. Variables also can be used for changing the graphical appearance of an element. For example, the variable LV describes on which level the current graphical element is placed. By changing the content of this variable, it is possible to move the element to a different level.