BWIPP Common Bindings API

Public API for the libpostscriptbarcode bindings that provide an object oriented interface to Barcode Writer in Pure PostScript.

Bindings are available for Java, Perl, Python and Ruby.

The methods of each binding relate to an equivalent C library function as follows:

Binding method	Related C library function
`BWIPP(...)` constructor	bwipp_load_from_file()
`BWIPP()` constructor	bwipp_load()
`~BWIPP()` destructor	bwipp_unload()
`get_version()`	bwipp_get_version()
`emit_required_resources(...)`	bwipp_emit_required_resources()
`emit_all_resources()`	bwipp_emit_all_resources()
`emit_exec(...)`	bwipp_emit_exec()
`list_families()`	bwipp_list_families_as_string()
`list_family_members(...)`	bwipp_list_family_members_as_string()
`list_properties(...)`	bwipp_list_properties_as_string()
`get_property(...)`	bwipp_get_property()

The basic workflow is to firstly initialise the library to load the PostScript resources by creating a new BWIPP object either with or without a filename. All subsequent methods are invoked on this object. You can then query the available barcode families with list_families() and list each family's members using list_family_members() to obtain the list of all supported barcode symbologies. The available properties of each barcode symbology can be enumerated using list_properties() and read with get_property(). To create a PostScript document concatenate together your own PostScript prolog with the output of either emit_required_resources() (minimal set of resources for a specific barcode symbology) or emit_all_resources() and you own PostScript code interspersed with calls to emit_exec() to render a barcode. The resources will be automatically released from the BWIPP object is garbage collected.

The bindings should be thread-safe provided that the calling code is limited to one thread per BWIPP object until the resources for the context have finished loading.

Examples

These example should make clear how the common API is manifest by each language.

Java

example.java:

import uk.co.terryburton.bwipp.*;

public class example {
  static {
    System.loadLibrary("postscriptbarcode");
  }

  public static void main(String args[]) {
        BWIPP bwipp = new BWIPP();
        if (bwipp.get_version() == null) {
                System.err.println("Failed to load resource");
                System.exit(1);
        }
        System.out.println("Packaged version: "+bwipp.get_version());
        String ps=bwipp.emit_all_resources();
        System.out.println("Packaged lines: "+ps.split("\r\n|\r|\n").length);
  }

}

Perl

example.pl:

#!/usr/bin/perl -w

use strict;
use postscriptbarcode;

my $bwipp=new postscriptbarcode::BWIPP() || die 'Failed to load resource\n';

my $ver=$bwipp->get_version() || die 'Failed to get version\n';
print "Packaged version: $ver\n";

my $ps=$bwipp->emit_all_resources();
my $lines=$ps=~tr/\n//;
print "Packaged lines: $lines\n";

Python

example.py:

#!/usr/bin/env python

import postscriptbarcode

bwipp=postscriptbarcode.BWIPP()
print("Packaged version: " + bwipp.get_version())

ps=bwipp.emit_all_resources()
print("Packaged lines: " + str(len(ps.split('\n'))))

Ruby

example.rb:

#!/usr/bin/env ruby

require 'postscriptbarcode'

bwipp=Postscriptbarcode::BWIPP.new()

puts "Packaged version: " + bwipp.get_version()
puts "Packaged lines: " + bwipp.emit_all_resources().lines.count.to_s