content-type

What is content-type?

The content-type npm package is used to create and parse HTTP Content-Type header according to RFC 7231. It allows you to parse content-type strings to objects and format content-type objects to strings.

What are content-type's main functionalities?

Parsing Content-Type

This feature allows you to parse a Content-Type string, returning an object with the media type and parameters like charset.

const contentType = require('content-type');
const parsed = contentType.parse('text/html; charset=utf-8');

Formatting Content-Type

This feature enables you to format an object representing a Content-Type into a string that can be used in HTTP headers.

const contentType = require('content-type');
const format = contentType.format({ type: 'text/html', parameters: { charset: 'utf-8' } });

Other packages similar to content-type

mime-types

The mime-types package is similar to content-type as it provides the ability to look up the content-type based on a file extension and vice versa. It is more focused on the association between file extensions and mime types rather than parsing and formatting Content-Type headers.

mime

The mime package is another alternative that allows you to map between MIME types and file extensions. It provides functionality to define custom mime type mappings and is more comprehensive in terms of the number of file types it supports compared to content-type.

negotiator

Negotiator is an HTTP content negotiation library that goes beyond just handling Content-Type headers. It can be used to negotiate language, charset, encoding, etc., based on the Accept-* headers from the client. It is more complex and offers broader functionality for handling HTTP negotiations.

README

Content-Type parsing

note: forked from here

new MediaType(type, [parameters])

The MediaType represents a parsed Media Type. For use in HTTP, the first (but only the first) q parameter will be parsed as a float. Other parameters are available through the params object. The first argument is the full media type, the second argument, if provided, is strictly a list of parameters.

The toString method converts the object back into a Media type.

var p = new MediaType('text/html;level=1;q=0.5');
p.q === 0.5;
p.params.level === "1"

var q = new MediaType('application/json', {profile: 'http://example.com/schema.json'});
q.type === "application/json";
q.params.profile === "http://example.com/schema.json";

q.q = 1;
q.toString() === 'application/json;q=1;profile="http://example.com/schema.json"';

parseMedia(type)

Returns a new instance of MediaType.

splitQuotedString(str, delimiter, quote)

Splits a string by a delimiter character (default: semicolon), ignoring quoted sections (default: double quote).

splitContentTypes(str)

Splits an Accept (or similar) header into an Array of strings of content-types.

splitContentType('application/json, text/html').map(parseMedia)

select(reps, accept)

Pick an ideal representation to send, given an Array of representations to choose from, and the client-preferred list as an Array.

See example.js for an example.

mediaCmp(a, b)

Accepts two MediaType instances and tests them for being a subset/superset.

If a is a superset of b (b is smaller than a), return 1. If b is a superset of a, return -1. If they are the exact same, return 0. If they are disjoint, return null.

The q-value, if any, is ignored.

mediaCmp(parseMedia('text/html'), parseMedia('text/html')) === 0
mediaCmp(parseMedia('*/*'), parseMedia('text/html')) === 1
mediaCmp(parseMedia('text/html;level=1'), parseMedia('text/html')) === -1
mediaCmp(parseMedia('application/json;profile="v1.json"'), parseMedia('application/json;profile="v2.json"')) === null