NielsLeenheer / CodepageEncoder

Codepage conversion library for obscure codepages supported by thermal printers
MIT License
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CodepageEncoder

A library for converting Unicode to obscure single byte codepage for use with thermal printers. This library is internally used by esc-pos-encoder, star-prnt-encoder and receipt-printer-encoder and limited in functionality. We recommend that you use another library like iconv or iconv-lite for use with your project – unless you really, really need the codepages that are supported by this library.

Usage

First, install the package using npm:

npm install @point-of-sale/codepage-encoder --save

Then, require the package and use it like so:

let CodepageEncoder = require('@point-of-sale/codepage-encoder');
CodepageEncoder.encode('ξεσκεπάζω την ψυχοφθόρα βδελυγμία', 'cp869');

Or import it as an ES module:

import CodepageEncoder from '@point-of-sale/codepage-encoder';
CodepageEncoder.encode('ξεσκεπάζω την ψυχοφθόρα βδελυγμία', 'cp869');

Methods

The following static methods are available for you to use. You don't need to instantiate the object first.

CodepageEncoder.encode

Encode the string to the codepage you specified. The result will be a Uint8Array containing all the bytes of the string in your codepage.

CodepageEncoder.encode('ξεσκεπάζω την ψυχοφθόρα βδελυγμία', 'cp869');

Result:

Uint8Array(33) [
    232, 222, 236, 228, 222, 234, 155,
    224, 250,  32, 238, 225, 231,  32,
    246, 242, 244, 233, 243, 226, 162,
    235, 214,  32, 215, 221, 222, 229,
    242, 216, 230, 159, 214
]

See the method CodepageEncoder.getEncodings() for determining which codepages are currently supported by this library.

CodepageEncoder.autoEncode

Encode the string with the most optimal set of codepages from the candidates codepages that you specified. The result will be a array of text fragments with the name of the codepage and an Uint8Array containing all the bytes of the string in that codepage.

CodepageEncoder.autoEncode('Qwerty ψυχοφθόρα på Съешь łódź', [
    'cp437', 'cp858', 'cp860', 'cp861', 'cp863', 'cp865', 'cp852', 'cp857', 'cp855', 'cp866', 'cp869'
]);

Result:

[
    {
        codepage: 'cp437',
        bytes: Uint8Array(7) [
            81, 119, 101,
            114, 116, 121,
            32
        ]
    },
    {
        codepage: 'cp869',
        bytes: Uint8Array(11) [
            246, 242, 244, 233,
            243, 226, 162, 235,
            214,  32, 112
        ]
    },
    { 
        codepage: 'cp437', 
        bytes: Uint8Array(2) [ 
            134, 32 
        ] 
    },
    {
        codepage: 'cp855',
        bytes: Uint8Array(6) [ 
            228, 158, 168, 245, 237, 32 
        ]
    },
    { 
        codepage: 'cp852', 
        bytes: Uint8Array(4) [ 
            136, 162, 100, 171 
        ] 
    }
]

See the method CodepageEncoder.getEncodings() for determining which codepages are currently supported by this library.

CodepageEncoder.supports

Determine if the specified codepage is supported. Return a boolean.

CodepageEncoder.supports('cp1119')

Result:

true

CodepageEncoder.getEncodings

Get the currently supported encodings. Returns an array of codepage identifiers.

CodepageEncoder.getEncodings()

Result:

[
    'cp437',       'cp720',       'cp737',       'cp775',
    'cp850',       'cp851',       'cp852',       'cp853',
    'cp855',       'cp857',       'cp858',       'cp860',
    'cp861',       'cp862',       'cp863',       'cp864',
    'cp865',       'cp866',       'cp869',       'cp874',
    'cp1098',      'cp1118',      'cp1119',      'cp1125',
    'cp1162',      'cp2001',      'cp3001',      'cp3002',
    'cp3011',      'cp3012',      'cp3021',      'cp3041',
    'cp3840',      'cp3841',      'cp3843',      'cp3844',
    'cp3845',      'cp3846',      'cp3847',      'cp3848',
    'iso88591',    'iso88592',    'iso88597',    'iso885915',
    'rk1048',      'windows1250', 'windows1251', 'windows1252',
    'windows1253', 'windows1254', 'windows1255', 'windows1256',
    'windows1257', 'windows1258'
]

CodepageEncoder.getTestStrings

Get a number of example strings that can be used for the codepage you specified.

CodepageEncoder.getTestStrings('cp865')

Result:

[
    { language: 'sv', string: 'Flygande bäckasiner söka strax hwila på mjuka tuvor.' },
    { language: 'dk', string: 'Quizdeltagerne spiste jordbær med fløde' }
]

License

MIT