linkify-it
Links recognition library with FULL unicode support.
Focused on high quality link patterns detection in plain text.
Demo
Why it's awesome:
- Full unicode support, with astral characters!
- International domains support.
- Allows rules extension & custom normalizers.
Install
npm install linkify-it --save
Browserification is also supported.
Usage examples
Example 1
import linkifyit from 'linkify-it';
const linkify = linkifyit();
// 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
linkify.add('@', {
validate: function (text, pos, self) {
const 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
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
.matchAtStart(text)
Checks if a match exists at the start of the string. Returns Match
(see docs for match(text)) or null if no URL is at the start.
Doesn't work with fuzzy links.
.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
