summernote `onCreateLink` options.

gistfile1.js

$('.summernote').summernote({
    /**
     * manipulate link address when user create link
     * @param {String} url
     * @return {String}
     */
    onCreateLink: function (url) {
        if (url.indexOf('http://') !== 0) {
            url = 'http://' + url;
        }
        return url;
    }
});