Re: Set activity filter to specific value
You’re right that the codex doesn’t always keep pace with the code. If you find something wrong in the codex, please take the initiative to fix it.
When troubleshooting, the most surefire way to figure out (for example) which arguments a given function takes is to look at the definition of that function, where the core coders do a great job of documenting what goes in and out of the main functions. I believe that bp_has_activities is defined in bp-activity/bp-activity-templatetags.php, but you can always find where a function is defined by shelling into your buddypress plugin directory (or keeping a local copy on your hard drive) and typing something like the following from the command line (unix/mac):
grep -nR 'bp_has_activites' ./
By scanning that list you should be able to find where the function is defined.
Another really great tool is the php xref http://bp-dev.org/phpxref/nav.html?_functions/index.html, but you should keep in mind that the version of BP cross referenced will not necessarily match your own.