Twitter text js , not calculating the length from text which contains urls with #!

Question

I am using Twitter text js to calculate length of text with urls containing #!. eg:

"Some text http://domain.com#!/path/p/56319216 #tag1 #tag2".

In firefox debugger error generates on this line in twitter text js

 twttr.txt.regexen.extractUrl.exec(text);

No specific error is logged instead my page freezes and alert me to stop the script, please help.

Waynant

If you want to calculate length of text then why not simply text.length? – Mikkimiko

@Mikkimiko Twitter wraps all urls in a tweet to t.co short urls. So I need to calculate length of tweet before sending to Twitter. – Waynant

Are you using the latest version from here github.com/twitter/twitter-text/tree/master/js/pkg ? – Coleslaw

Answer 1

A pull request as been merged on the github repository on 2012-05-31 introducing the twttr.txt.getTweetLength(text, options) function that is taking consideration to t.co URLs and defined as follow :

twttr.txt.getTweetLength = function(text, options) {
if (!options) {
    options = {
        short_url_length: 22,
        short_url_length_https: 23
    };
}
var textLength = text.length;
var urlsWithIndices = twttr.txt.extractUrlsWithIndices(text);

for (var i = 0; i < urlsWithIndices.length; i++) {
    // Subtract the length of the original URL
    textLength += urlsWithIndices[i].indices[0] -urlsWithIndices[i].indices[1];

    // Add 21 characters for URL starting with https://
    // Otherwise add 20 characters
    if (urlsWithIndices[i].url.toLowerCase().match(/^https:\/\//)) {
        textLength += options.short_url_length_https;
    } else {
        textLength += options.short_url_length;
    }
}

return textLength;
};

So your function will just become :

function charactersleft(tweet) {
return 140 - twttr.txt.getTweetLength(tweet);
}

Plus, regarding the best practices with t.co we should retrieve the short_url_length and short_url_length_https values from twitter and pass them as the options parameter in the twttr.txt.getTweetLength function :

Request GET help/configuration once daily in your application and cache the "short_url_length" (t.co's current maximum length value) for 24 hours. Cache "short_url_length_https" (the maximum length for HTTPS-based t.co links) and use it as the length of HTTPS-based URLs. Especially knowing that some changes in the t.co urls length will be effective on 2013-02-20 as described in the twitter developer blog

Gosport