structured-headers

Structured Headers parser for Javascript

This library is a parser for the structured headers specification. Currently it's still a draft, so this package is also in alpha until the specification stabilizes as a RFC.

Installation

Using npm:

npm install structured-headers

API

Parsing an item

The following are examples of item headers:

Parsed as string

# Parsed into string
Header: "foo"
Header: bar

# Parsed into number
Header: 5
Header: -10
Header: 5.01415

# Parsed into boolean
Header: ?T
Header: ?F

To parse these header values, use parseItem:

const sh = require('structured-headers');
console.log(sh.parseItem(header));

Parsing a list

Lists contain items separated by comma Here's an example

Header: 5, "foo", bar, ?T

To parse these:

const sh = require('structured-headers');
console.log(sh.parseList(header));

This will result in [5, "foo", "bar", true].

Parsing a dictionary

A dictionary is a key->value object. Examples:

Example: foo: "Bar"; baz: 5

Dictionary keys can be any item. This is parsed with:

const sh = require('structured-headers');
console.log(sh.parseDictionary(header));

The output for this is an object: { foo: 'bar', baz: 5}.

Parsing a list of lists

A list of list is a 2-dimensional array. The top level is separated by commas, and the second level is separated by semi-colons.

Every member in this list can be any item (string, boolean, number).

Example: "foo";"bar", "baz", "bat"; "one"

Parsing:

const sh = require('structured-headers');
console.log(sh.parseListList(header));

This will result in [['foo', 'bar'], ['baz'], ['bat', 'one']].

Parsing a parameterized list

A parameterized list is a list for which every member can have one or more parameters, specified as a dictionary.

ExampleParamList: foo; param1: "value1", bar; "param2": "value2"

Parsing:

const sh = require('structured-headers');
console.log(sh.parseParamList(header));

This will result in [['foo', { param1: "value1" }], ['bar', { param2: "value2" }].

Browser support

There is a minified version of this library in the browser/ directory. This minified file will expose a global variable called 'structuredHeader' which contains the rest of the api.