multiformats
⛔️ DEPRECATED: This module has been superseded by the multiformats module
js-cid
CID implementation in JavaScript.
Lead Maintainer
Table of Contents
- Install
- Usage
- API
- Contribute
- License
Install
In Node.js through npm
$ npm install --save cidsBrowser: Browserify, Webpack, other bundlers
The code published to npm that gets loaded on require is in fact an ES5 transpiled version with the right shims added. This means that you can require it and use with your favourite bundler without having to adjust asset management process.
const CID = require('cids')In the Browser through <script> tag
Loading this module through a script tag will make the Cids obj available in the global namespace.
<script src="https://unpkg.com/cids/dist/index.min.js"></script>
<!-- OR -->
<script src="https://unpkg.com/cids/dist/index.js"></script>Usage
You can create an instance from a CID string or CID Uint8Array
const CID = require('cids')
const cid = new CID('bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsu')
cid.version // 1
cid.codec // 'dag-pb'
cid.code // 112
cid.multibaseName // 'base32'
cid.toString()
// 'bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsu'or by specifying the cid version, multicodec name and multihash:
const CID = require('cids')
const multihashing = require('multihashing-async')
const bytes = new TextEncoder('utf8').encode('OMG!')
const hash = await multihashing(bytes, 'sha2-256')
const cid = new CID(1, 'dag-pb', hash)
console.log(cid.toString())
// bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsuThe multicodec integer code can also be used to create a new CID:
const cid = new CID(1, 112, hash)
console.log(cid.toString())
// bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsuThe string form of v1 CIDs defaults to base32 encoding (v0 CIDs are always base58btc encoded). When creating a new instance you can optionally specify the default multibase to use when calling toBaseEncodedString() or toString()
const cid = new CID(1, 'raw', hash, 'base64')
console.log(cid.toString())
// mAXASIN69ets85WVE0ipva5M5b2mAqAZ8LME08PeAG2MxCSuVIf you construct an instance from a valid CID string, the base you provided will be preserved as the default.
// e.g. a base64url encoded CID
const cid = new CID('uAXASIHJSUj5lkfuP5VPWf_VahvhARLRqPkF24QxY-lKaSqvV')
cid.toString()
// uAXASIHJSUj5lkfuP5VPWf_VahvhARLRqPkF24QxY-lKaSqvVAPI
CID.isCID(cid)
Returns true if object is a valid CID instance, false if not valid.
It's important to use this method rather than instanceof checks in
order to handle CID objects from different versions of this module.
CID.validateCID(cid)
Validates the different components (version, codec, multihash, multibaseName) of the CID
instance. Throws an Error if not valid.
new CID(version, codec, multihash, [multibaseName])
version must be either 0 or 1.
codec must be a string of a valid registered codec.
multihash must be a Uint8Array instance of a valid multihash.
multibaseName optional string. Must be a valid multibase name. Default is base58btc for v0 CIDs or base32 for v1 CIDs.
new CID(baseEncodedString)
Additionally, you can instantiate an instance from a base encoded string.
new CID(Uint8Array)
Additionally, you can instantiate an instance from a Uint8Array.
cid.codec
Property containing the string identifier of the codec.
cid.code
Property containing the integer identifier of the codec.
cid.version
Property containing the CID version integer.
cid.multihash
Property containing the multihash Uint8Array.
cid.multibaseName
Property containing the default base to use when calling .toString
cid.bytes
Property containing the full CID encoded as a Uint8Array.
cid.prefix
Proprety containing a Uint8Array of the CID version, codec, and the prefix
section of the multihash.
cid.toV0()
Returns the CID encoded in version 0. Only works for dag-pb codecs.
Throws if codec is not dag-pb.
cid.toV1()
Returns the CID encoded in version 1.
cid.toBaseEncodedString(base=this.multibaseName)
Returns a base encoded string of the CID. Defaults to the base encoding in this.multibaseName.
The value of this.multibaseName depends on how the instance was constructed:
- If the CID was constructed from an object that already had a multibase (a string or an existing CID) then it retains that base.
- If the CID was constructed from an object that did not have a multibase (a
Uint8Array, or by passing only version + codec + multihash to the constructor), thenmultibaseNamewill bebase58btcfor a v0 CID orbase32for a v1 CID.
cid.toString(base=this.multibaseName)
Shorthand for cid.toBaseEncodedString described above.
cid.equals(cid)
Compare cid instance. Returns true if CID's are identical, false if otherwise.
Contribute
Contributions welcome. Please check out the issues.
Check out our contributing document for more information on how we work, and about contributing in general. Please be aware that all interactions related to multiformats are subject to the IPFS Code of Conduct.
Small note: If editing the Readme, please conform to the standard-readme specification.
License
MIT