mailcheck
Version:
A standalone module that suggests a right domain when your users misspell it in an email address.
268 lines (228 loc) • 8.62 kB
JavaScript
/*
* Mailcheck https://github.com/mailcheck/mailcheck
* Author
* Derrick Ko (@derrickko)
*
* Released under the MIT License.
*
* v 1.1.1
*/
var Mailcheck = {
domainThreshold: 2,
secondLevelThreshold: 2,
topLevelThreshold: 2,
defaultDomains: ['msn.com', 'bellsouth.net',
'telus.net', 'comcast.net', 'optusnet.com.au',
'earthlink.net', 'qq.com', 'sky.com', 'icloud.com',
'mac.com', 'sympatico.ca', 'googlemail.com',
'att.net', 'xtra.co.nz', 'web.de',
'cox.net', 'gmail.com', 'ymail.com',
'aim.com', 'rogers.com', 'verizon.net',
'rocketmail.com', 'google.com', 'optonline.net',
'sbcglobal.net', 'aol.com', 'me.com', 'btinternet.com',
'charter.net', 'shaw.ca'],
defaultSecondLevelDomains: ["yahoo", "hotmail", "mail", "live", "outlook", "gmx"],
defaultTopLevelDomains: ["com", "com.au", "com.tw", "ca", "co.nz", "co.uk", "de",
"fr", "it", "ru", "net", "org", "edu", "gov", "jp", "nl", "kr", "se", "eu",
"ie", "co.il", "us", "at", "be", "dk", "hk", "es", "gr", "ch", "no", "cz",
"in", "net", "net.au", "info", "biz", "mil", "co.jp", "sg", "hu"],
run: function(opts) {
opts.domains = opts.domains || Mailcheck.defaultDomains;
opts.secondLevelDomains = opts.secondLevelDomains || Mailcheck.defaultSecondLevelDomains;
opts.topLevelDomains = opts.topLevelDomains || Mailcheck.defaultTopLevelDomains;
opts.distanceFunction = opts.distanceFunction || Mailcheck.sift3Distance;
var defaultCallback = function(result){ return result };
var suggestedCallback = opts.suggested || defaultCallback;
var emptyCallback = opts.empty || defaultCallback;
var result = Mailcheck.suggest(Mailcheck.encodeEmail(opts.email), opts.domains, opts.secondLevelDomains, opts.topLevelDomains, opts.distanceFunction);
return result ? suggestedCallback(result) : emptyCallback()
},
suggest: function(email, domains, secondLevelDomains, topLevelDomains, distanceFunction) {
email = email.toLowerCase();
var emailParts = this.splitEmail(email);
if (secondLevelDomains && topLevelDomains) {
// If the email is a valid 2nd-level + top-level, do not suggest anything.
if (secondLevelDomains.indexOf(emailParts.secondLevelDomain) !== -1 && topLevelDomains.indexOf(emailParts.topLevelDomain) !== -1) {
return false;
}
}
var closestDomain = this.findClosestDomain(emailParts.domain, domains, distanceFunction, this.domainThreshold);
if (closestDomain) {
if (closestDomain == emailParts.domain) {
// The email address exactly matches one of the supplied domains; do not return a suggestion.
return false;
} else {
// The email address closely matches one of the supplied domains; return a suggestion
return { address: emailParts.address, domain: closestDomain, full: emailParts.address + "@" + closestDomain };
}
}
// The email address does not closely match one of the supplied domains
var closestSecondLevelDomain = this.findClosestDomain(emailParts.secondLevelDomain, secondLevelDomains, distanceFunction, this.secondLevelThreshold);
var closestTopLevelDomain = this.findClosestDomain(emailParts.topLevelDomain, topLevelDomains, distanceFunction, this.topLevelThreshold);
if (emailParts.domain) {
var closestDomain = emailParts.domain;
var rtrn = false;
if(closestSecondLevelDomain && closestSecondLevelDomain != emailParts.secondLevelDomain) {
// The email address may have a mispelled second-level domain; return a suggestion
closestDomain = closestDomain.replace(emailParts.secondLevelDomain, closestSecondLevelDomain);
rtrn = true;
}
if(closestTopLevelDomain && closestTopLevelDomain != emailParts.topLevelDomain) {
// The email address may have a mispelled top-level domain; return a suggestion
closestDomain = closestDomain.replace(emailParts.topLevelDomain, closestTopLevelDomain);
rtrn = true;
}
if (rtrn == true) {
return { address: emailParts.address, domain: closestDomain, full: emailParts.address + "@" + closestDomain };
}
}
/* The email address exactly matches one of the supplied domains, does not closely
* match any domain and does not appear to simply have a mispelled top-level domain,
* or is an invalid email address; do not return a suggestion.
*/
return false;
},
findClosestDomain: function(domain, domains, distanceFunction, threshold) {
threshold = threshold || this.topLevelThreshold;
var dist;
var minDist = 99;
var closestDomain = null;
if (!domain || !domains) {
return false;
}
if(!distanceFunction) {
distanceFunction = this.sift3Distance;
}
for (var i = 0; i < domains.length; i++) {
if (domain === domains[i]) {
return domain;
}
dist = distanceFunction(domain, domains[i]);
if (dist < minDist) {
minDist = dist;
closestDomain = domains[i];
}
}
if (minDist <= threshold && closestDomain !== null) {
return closestDomain;
} else {
return false;
}
},
sift3Distance: function(s1, s2) {
// sift3: http://siderite.blogspot.com/2007/04/super-fast-and-accurate-string-distance.html
if (s1 == null || s1.length === 0) {
if (s2 == null || s2.length === 0) {
return 0;
} else {
return s2.length;
}
}
if (s2 == null || s2.length === 0) {
return s1.length;
}
var c = 0;
var offset1 = 0;
var offset2 = 0;
var lcs = 0;
var maxOffset = 5;
while ((c + offset1 < s1.length) && (c + offset2 < s2.length)) {
if (s1.charAt(c + offset1) == s2.charAt(c + offset2)) {
lcs++;
} else {
offset1 = 0;
offset2 = 0;
for (var i = 0; i < maxOffset; i++) {
if ((c + i < s1.length) && (s1.charAt(c + i) == s2.charAt(c))) {
offset1 = i;
break;
}
if ((c + i < s2.length) && (s1.charAt(c) == s2.charAt(c + i))) {
offset2 = i;
break;
}
}
}
c++;
}
return (s1.length + s2.length) /2 - lcs;
},
splitEmail: function(email) {
var parts = email.trim().split('@');
if (parts.length < 2) {
return false;
}
for (var i = 0; i < parts.length; i++) {
if (parts[i] === '') {
return false;
}
}
var domain = parts.pop();
var domainParts = domain.split('.');
var sld = '';
var tld = '';
if (domainParts.length == 0) {
// The address does not have a top-level domain
return false;
} else if (domainParts.length == 1) {
// The address has only a top-level domain (valid under RFC)
tld = domainParts[0];
} else {
// The address has a domain and a top-level domain
sld = domainParts[0];
for (var i = 1; i < domainParts.length; i++) {
tld += domainParts[i] + '.';
}
tld = tld.substring(0, tld.length - 1);
}
return {
topLevelDomain: tld,
secondLevelDomain: sld,
domain: domain,
address: parts.join('@')
}
},
// Encode the email address to prevent XSS but leave in valid
// characters, following this official spec:
// http://en.wikipedia.org/wiki/Email_address#Syntax
encodeEmail: function(email) {
var result = encodeURI(email);
result = result.replace('%20', ' ').replace('%25', '%').replace('%5E', '^')
.replace('%60', '`').replace('%7B', '{').replace('%7C', '|')
.replace('%7D', '}');
return result;
}
};
// Export the mailcheck object if we're in a CommonJS env (e.g. Node).
// Modeled off of Underscore.js.
if (typeof module !== 'undefined' && module.exports) {
module.exports = Mailcheck;
}
// Support AMD style definitions
// Based on jQuery (see http://stackoverflow.com/a/17954882/1322410)
if (typeof define === "function" && define.amd) {
define("mailcheck", [], function() {
return Mailcheck;
});
}
if (typeof window !== 'undefined' && window.jQuery) {
(function($){
$.fn.mailcheck = function(opts) {
var self = this;
if (opts.suggested) {
var oldSuggested = opts.suggested;
opts.suggested = function(result) {
oldSuggested(self, result);
};
}
if (opts.empty) {
var oldEmpty = opts.empty;
opts.empty = function() {
oldEmpty.call(null, self);
};
}
opts.email = this.val();
Mailcheck.run(opts);
}
})(jQuery);
}