DG object classes
A detailed understanding of DG objects is required especially when writing sophisticated scripts.
GROUP
This object is an invisible object which links other objects together. The GROUP object can then be used as a handle to manage this linked set as one entity.
SYMBOL
The DG SYMBOL is a combination of the graphics symbol (DW SYMBOL) and the NODE points.
CLINE
The connection line. This object is a graphics line with at least two NODE points. There are nodes at each end of the CLINE, and possibly additional points between the ends (branching points). Clines are visualized via polylines. Also polylines implemented as 2D symbols can be used.
LABELS
This visual object type is used for visualizing some attributes of groups, symbols and connection lines. Data is extracted from the database, formatted, and printed via a suitable 2D symbol.
A label is a kind of tag symbol for a PD object. We say that a DG LABEL has a link upwards in the hierarchy to the PD object. A typical example of a label is the position id label. The id text is not written by the user; the label extracts the id information from the database after the user has picked the object which is to be tagged.
There are two label types:
- Text – This type of label is used to plot some information related to the picked PD object. The argument list for these labels is as for symbolic text: STRING text_string, ref_x, ref_y, stringlen, char_height, char_width, char_spacing, text_origin, text_direction, text_slant, color, pen.
- Symbol – This type is used typically to add some decorations to connection lines, e.g. flow arrow markers, insulation markers, etc. There is no support for arguments of 2D symbols.
CPOINT
A connection point, which knows its geometric location and if any other objects are linked to the same connection point. NODE points of symbols and connection lines can be linked with a connection point.
NODE
A node knows its geometric location inside a SYMBOL and the link to a connection point if the node is connected. Node direction (direction vector) and type of flow (in/out/any) are also defined for nodes. Nodes are defined in most of the cases as 2D symbols but for CLINES the system generates the ends.
New nodes can also be added to symbols after they are placed. This is done while routing connection lines (pipe runs and instrument lines).