node-ldif

Nodejs LDIF (LDAP Data Interchange Format) parser based on RFC2849

Unless you are an LDAP aficionado you may not know about the LDIF format. I was surprised to learn that no LDIF parsing library existed for node. So I wrote one, with peg.js.

Now I'll never have to use that cursed perl script again!

Design Goals

• 100% RFC-compliance; should comprehend any valid LDIF file
• Parsed records stored internally intact
• Methods are provided to extract record data in various formats
• Outputs exactly compatible LDIF for any parsed record or file
• Automatic decoding and outputting of base64 data
• No external library dependencies; pure Node Javascript
• Includes complete test suite
• The library can parse special language characters

Usage

Installation

Install easily with npm!

npm install ldif

Parsing

Parsing strings

var ldif = require('ldif'),
    file = './rfc/example1.ldif',
    input = require('fs').readFileSync(file,'utf8');

console.log(ldif.parse(input));

After reading the file, it's parsed as a string.
There's also a shorthand to read in a file (synchronously, as above):

File parsing shorthand

var ldif = require('ldif');
console.log(ldif.parseFile('./rfc/example1.ldif'));

Parsing an LDIF file returns an object format for an entire LDIF file.
In this case, example1.ldif specifies contents of two LDAP records.

Shifting records from parsed file

var ldif = require('ldif');
    file = ldif.parseFile('./rfc/example1.ldif');

var record = file.shift();

Records are stored in an internal format, using classic Javascript objects. The type or value specified in a type property for all objects, but they can also be tested for specific constructor types:

var ldif = require('ldif');
    file = ldif.parseFile('./rfc/example1.ldif');

(file instanceof ldif.Container)        === true
(file.shift() instanceof ldif.Record)   === true

Converting

Record to plain object

var ldif = require('ldif');
    file = ldif.parseFile('./rfc/example1.ldif'),
    output_options = {};

var record = file.shift();
console.log(record.toObject(output_options));

Output of the above code is this:

{ dn: 'cn=Barbara Jensen, ou=Product Development, dc=airius, dc=com',
  attributes: 
   { objectclass: [ 'top', 'person', 'organizationalPerson' ],
     cn: [ 'Barbara Jensen', 'Barbara J Jensen', 'Babs Jensen' ],
     sn: 'Jensen',
     uid: 'bjensen',
     telephonenumber: '+1 408 555 1212',
     description: 'A big sailing fan.' } }

Notice the default behavior outputs attribute key/value pairs that have values of either an array or single string. Since an attribute can be single- or multi-valued, this format makes sense in most cases.

toObject(options)

The behavior of toObject() can be altered with options below.

Option | Type | Description | Deafult ------ | ---- | ----------- | ---------- flatten | boolean | Flatten single values into strings | true single | boolean | Overrides flatten, only returns single values | false decode | boolean | Decode values (not yet well-defined, leave true) | true preserveOptions | boolean | Outputs any attribute options | true preferOptions | array | Prefer these options when preserveOptions is false | [ ]

Outputting LDIF for parsed files

All parsed data can be written back to LDIF format using a toLDIF() method (on files or entries).

var ldif = require('ldif');
    file = ldif.parseFile('./rfc/example1.ldif');

// the whole file
console.log(file.toLDIF());

// or just a single record
console.log(file.shift().toLDIF());

Note: toLDIF() method folds lines by default at 78 characters. If you want to change this value call toLDIF(width) where width is an integer.

Tests

To run the test suite, use npm test (you'll need the dev dependencies of mocha and chai installed).

Rebuild parser

To modify the parser, edit lib/ldif.pegjs and run npm run make (this requires the pegjs dev dependency to be installed).

TODO

• Streaming read interface (coming soon--probably as a seperate package)
• Construct and alter objects through code (document this)
• More complete documentation