Instead of calling the function:
base_url()
for every single link, would it make sense to define your base url in constants.php:
define('BASE_URL', 'http://mysite.com/');
and then use that constant so that the function call isn't potentially made many multiple times on a page?
Not entirely. You'll run into unexpected behavior if you use any of the following functions:
redirect()site_url()base_url()form_open()anchor()That's not an exhaustive list--many other functions depend on the base url config setting. A better approach might be to use relative links instead, rather than hard-coding absolute URLs.
I, myself, have been tempted to use site_url() to define every link as a measure of paranoia (wondering to myself whether the URL structure will ever change). But really, undergoing a massive overhaul of the sitemap will create more difficult problems than just the links. For the sake of development, I now just use relative links where it makes sense.
Cheers!
In my opinion, I wouldn't worry about multiple calls to base_url() - I doubt it will have a significant impact on performance.
Additionally, I dislike the idea of using a constant because the base URL will essentially be defined twice, in two different places. Once in config.php and once wherever the BASE_URL constant would live. However, that's just my thought on it - perhaps someone else could make the case for it.
tl;dr I don't think multiple calls to base_url() is a problem and, in most cases, probably won't have a significant impact on performance.
