Return a data frame with specifications for descriptor and graphical property fields required for certain object classes used within the package. This is an internal function, not intended to be called by package users.
dfSpecs(objClass)
A data frame with one row per descriptor or graphical property field.
Columns are name
(the name of the field); mode
(mode/type of
values taken by the field); and NA_ok
(logical, TRUE if NA is a
valid value for the field).
Field names are used as the row names of the data frame.
One of tblEntries
, prEntries
, tblBlocks
,
prBlocks
, or prHvrules
.
Descriptor and graphical property fields are documented in
?elements
.
df_from_spec
, which uses the output from this function to
create a template data frame containing the required fields;
grSpecs
, which returns specifications for the graphical
properties for each element type.