Browse Prior Art Database

Using Line Data as Control Variables

IP.com Disclosure Number: IPCOM000118162D
Original Publication Date: 1996-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 134K

Publishing Venue

IBM

Related People

DeBry, RK: AUTHOR [+2]

Abstract

Data formatted for line printers (or "line data") is very common among corporate computer applications. The Advanced Function Printing (AFP) Page Definitions of IBM* can extract fields from line data to format on today's more sophisticated pages. The line data supplies the data and the page definition describes what to do with that data. Currently, line data is used to: o supply text data on a page, and o supply test arguments for conditional processing

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 37% of the total text.

Using Line Data as Control Variables

      Data formatted for line printers (or "line data") is very
common among corporate computer applications.  The Advanced Function
Printing (AFP) Page Definitions of IBM* can extract fields from line
data to format on today's more sophisticated pages.  The line data
supplies the data and the page definition describes what to do with
that data.  Currently, line data is used to:
  o  supply text data on a page, and
  o  supply test arguments for conditional processing

This article describes a third use for line data, to:
  o  supply control variables that modify AFP objects -- vary
      their position, orientation, scale and data content.

      There are many practical needs for this ability.  As an
example, a utilities company would be able to show customers their
monthly usage statistics in a bar chart instead of with lists of
numbers.  The height of the bars is derived from the customer's
record in the line data.

      Line data control variables can be passed to AFP PostScript
Container objects.  They then become parameters to sophisticated
PostScript routines with even more elaborate printed results, such as
custom pie charts where line data controls such things as:
  o  the diameter of the chart
  o  the angle of each wedge
  o  each wedge's color
  o  each wedge's fill pattern

      Customer's line data can be married with the general
programmability of PostScript to produce complex results.

      Line data control variables can be passed to other AFP objects,
as well.  For example, the content of a bar code object might come
from line data, allowing customers to print a customized bar code on
their document.  Variables can also scale and position images and
graphics objects.

      There are two steps to the using of line data in this way:
identifying line data control variables and using the variables to
modify an object.  For clarity, these steps are described using a
proposed syntax extension to Page Printer Formatting Aid (PPFA), a
product that creates AFP page definitions.

      Identifying Line Data Control Variables
  There are three steps to identifying a line data control variable:
  1.  identify which line in the line data file
  2.  identify which field in the line
  3.  apply an arithmetic expression to the field contents
       to convert them into the desired control variable

      In PPFA, the "PRINTLINE"  command identifies which line in the
file.  Line Data Control Variables are identified with a new
subcommand for "PRINTLINE"  that defines the field and arithmetic
expression:
  VARIABLE varname
    START n
    LENGTH n
    ( EXPR expression )
  where
  VARIABLE    identifies the name of the control variable
  START       identifies the start position of the data within
               the print line
  LENGTH      identifies how many line data characters are
...