'>>> from django_facebook.api import FacebookApi
>>> url_text = \'http://www.google.com blabla\'
>>> FacebookAPI._extract_url(url_text)
u\'http://www.google.com/\'
>>> url_text = \'http://www.google.com/\'
>>> FacebookAPI._extract_url(url_text)
u\'http://www.google.com/\'
>>> url_text = \'google.com/\'
>>> FacebookAPI._extract_url(url_text)
u\'http://google.com/\'
>>> url_text = \'http://www.fahiolista.com/www.myspace.com/www.google.com\'
>>> FacebookAPI._extract_url(url_text)
u\'http://www.fahiolista.com/www.myspace.com/www.google.com\''

@classmethod
def _extract_url(cls, text_url_field):

    import re
    text_url_field = text_url_field.encode('utf8')
    seperation = re.compile('[    ,;\n\r]+')
    try:
        parts = seperation.split(text_url_field)
    except TypeError:
        parts = seperation.split(text_url_field.decode())
    for part in parts:
        from django_facebook.utils import get_url_field
        url_check = get_url_field()
        try:
            clean_url = url_check.clean(part)
            return clean_url
        except ValidationError:
            continue
