linkify-it
==========
[](https://travis-ci.org/markdown-it/linkify-it)
[](https://www.npmjs.org/package/linkify-it)
[](https://coveralls.io/r/markdown-it/linkify-it?branch=master)
[](https://gitter.im/markdown-it/linkify-it)
> Links recognition library with FULL unicode support.
> Focused on high quality link patterns detection in plain text.
__[Demo](http://markdown-it.github.io/linkify-it/)__
Why it's awesome:
- Full unicode support, _with astral characters_!
- International domains support.
- Allows rules extension & custom normalizers.
Install
-------
```bash
npm install linkify-it --save
```
Browserification is also supported.
Usage examples
--------------
##### Example 1
```js
var linkify = require('linkify-it')();
// Reload full tlds list & add unofficial `.onion` domain.
linkify
.tlds(require('tlds')) // Reload with full tlds list
.tlds('onion', true) // Add unofficial `.onion` domain
.add('git:', 'http:') // Add `git:` protocol as "alias"
.add('ftp:', null) // Disable `ftp:` protocol
.set({ fuzzyIP: true }); // Enable IPs in fuzzy links (without schema)
console.log(linkify.test('Site github.com!')); // true
console.log(linkify.match('Site github.com!')); // [ {
// schema: "",
// index: 5,
// lastIndex: 15,
// raw: "github.com",
// text: "github.com",
// url: "http://github.com",
// } ]
```
##### Example 2. Add twitter mentions handler
```js
linkify.add('@', {
validate: function (text, pos, self) {
var tail = text.slice(pos);
if (!self.re.twitter) {
self.re.twitter = new RegExp(
'^([a-zA-Z0-9_]){1,15}(?!_)(?=$|' + self.re.src_ZPCc + ')'
);
}
if (self.re.twitter.test(tail)) {
// Linkifier allows punctuation chars before prefix,
// but we additionally disable `@` ("@@mention" is invalid)
if (pos >= 2 && tail[pos - 2] === '@') {
return false;
}
return tail.match(self.re.twitter)[0].length;
}
return 0;
},
normalize: function (match) {
match.url = 'https://twitter.com/' + match.url.replace(/^@/, '');
}
});
```
API
---
__[API documentation](http://markdown-it.github.io/linkify-it/doc)__
### new LinkifyIt(schemas, options)
Creates new linkifier instance with optional additional schemas.
Can be called without `new` keyword for convenience.
By default understands:
- `http(s)://...` , `ftp://...`, `mailto:...` & `//...` links
- "fuzzy" links and emails (google.com, foo@bar.com).
`schemas` is an object, where each key/value describes protocol/rule:
- __key__ - link prefix (usually, protocol name with `:` at the end, `skype:`
for example). `linkify-it` makes sure that prefix is not preceded with
alphanumeric char.
- __value__ - rule to check tail after link prefix
- _String_ - just alias to existing rule
- _Object_
- _validate_ - either a `RegExp` (start with `^`, and don't include the
link prefix itself), or a validator function which, given arguments
_text_, _pos_, and _self_, returns the length of a match in _text_
starting at index _pos_. _pos_ is the index right after the link prefix.
_self_ can be used to access the linkify object to cache data.
- _normalize_ - optional function to normalize text & url of matched result
(for example, for twitter mentions).
`options`:
- __fuzzyLink__ - recognize URL-s without `http(s)://` head. Default `true`.
- __fuzzyIP__ - allow IPs in fuzzy links above. Can conflict with some texts
like version numbers. Default `false`.
- __fuzzyEmail__ - recognize emails without `mailto:` prefix. Default `true`.
- __---__ - set `true` to terminate link with `---` (if it's considered as long dash).
### .test(text)
Searches linkifiable pattern and returns `true` on success or `false` on fail.
### .pretest(text)
Quick check if link MAY BE can exist. Can be used to optimize more expensive
`.test()` calls. Return `false` if link can not be found, `true` - if `.test()`
call needed to know exactly.
### .testSchemaAt(text, name, offset)
Similar to `.test()` but checks only specific protocol tail exactly at given
position. Returns length of found pattern (0 on fail).
### .match(text)
Returns `Array` of found link matches or null if nothing found.
Each match has:
- __schema__ - link schema, can be empty for fuzzy links, or `//` for
protocol-neutral links.
- __index__ - offset of matched text
- __lastIndex__ - index of next char after mathch end
- __raw__ - matched text
- __text__ - normalized text
- __url__ - link, generated from matched text
### .tlds(list[, keepOld])
Load (or merge) new tlds list. Those are needed for fuzzy links (without schema)
to avoid false positives. By default:
- 2-letter root zones are ok.
- biz|com|edu|gov|net|org|pro|web|xxx|aero|asia|coop|info|museum|name|shop|рф are ok.
- encoded (`xn--...`) root zones are ok.
If that's not enough, you can reload defaults with more detailed zones list.
### .add(key, value)
Add a new schema to the schemas object. As described in the constructor
definition, `key` is a link prefix (`skype:`, for example), and `value`
is a String to alias to another schema, or an Object with `validate` and
optionally `normalize` definitions. To disable an existing rule, use
`.add(key, null)`.
### .set(options)
Override default options. Missed properties will not be changed.
## License
[MIT](https://github.com/markdown-it/linkify-it/blob/master/LICENSE)
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