How do you know when to add your action to init or wp_head. In particular with regards to scripts and styles, but also any other action.
1 Answer
From Codex Action Reference:
initRuns after WordPress has finished loading but before any
headers are sent. Useful for
intercepting $_GET or $_POST triggers.
wp_headRuns when the template calls the wp_head function. This hook
is generally placed near the top of a
page template between <head> and
</head>. This hook does not take any
parameters.
Basically wp_head runs when page is already being loaded, while init runs before that.
Also don’t forget that init fires on admin pages as well and anything front-end related must be excluded from there with !is_admin() check.