jpotts18 jpotts18 - 1 year ago 47
Node.js Question

how to pull @ mentions out of strings like twitter in javascript

I am writing an application in Node.js that allows users to mention each other in messages like on twitter. I want to be able to find the user and send them a notification. In order to do this I need to pull @usernames to find mentions from a string in node.js?

Any advice, regex, problems?

Answer Source

I have found that this is the best way to find mentions inside of a string in javascript.

var str = "@jpotts18 what is up man? Are you hanging out with @kyle_clegg";
var pattern = /\B@[a-z0-9_-]+/gi;
["@jpotts18", "@kyle_clegg"]

I have purposefully restricted it to upper and lowercase alpha numeric and (-,_) symbols in order to avoid periods that could be confused for usernames like (@j.potts).

This is what twitter-text.js is doing behind the scenes.

// Mention related regex collection
twttr.txt.regexen.validMentionPrecedingChars = /(?:^|[^a-zA-Z0-9_!#$%&*@@]|RT:?)/;
twttr.txt.regexen.atSigns = /[@@]/;
twttr.txt.regexen.validMentionOrList = regexSupplant(
    '(#{validMentionPrecedingChars})' +  // $1: Preceding character
    '(#{atSigns})' +                     // $2: At mark
    '([a-zA-Z0-9_]{1,20})' +             // $3: Screen name
    '(\/[a-zA-Z][a-zA-Z0-9_\-]{0,24})?'  // $4: List (optional)
  , 'g');
twttr.txt.regexen.endMentionMatch = regexSupplant(/^(?:#{atSigns}|[#{latinAccentChars}]|:\/\/)/);

Please let me know if you have used anything that is more efficient, or accurate. Thanks!