Change update-links to be wp-cron compatible

[Otto42]

update-links.php is a file that does little other than to update the links link_updated times using pingomatic when it's called. However, there's nothing in Wordpress to run it at all. The trigger has to be external.

With the addition of wp-cron to the 2.1 line, the update-links.php file should be wrapped in a function with an action hook and included into the main source, so that wp-cron can trigger it on some basis.

Further suggestion: Rig the "track link update times" checkbox on Options->Misc to activate and deactivate this wp-cron job as needed. The checking timer can be set to, say, 1-2 hours or so. Add a filter to the timer so that it can be easily modified if needed. Or make it an option or something.

[rob1n]

Seems like a good use of WP-Cron.

[Otto42]

Added patch to move update links into a cron job. Features of this patch:

• Adds two new functions. One does the updating of the links, the other manages the wp-cron scheduling based on the enabling/disabling of the links update option.
• Scheduling frequency is filtered for easy plugin changing (defaults to daily).
• Both new functions are pluggable, in case a plugin wants to change how the updating or scheduling works entirely.

[Otto42]

Makes update links functionality into a wp-cron job.

[markjaquith]

What is your plan for update-links.php ? Update it to use this function? Delete it altogether?

[Otto42]

Delete it altogether. The only reason to have it separate is so it can be executed separately as a cron job. With wp-cron doing it, there's no reason to have it at all. And with the function being pluggable, plugins can replace it if they like.

[markjaquith]

Sounds fine. This should be good to go in after a little testing.

[Otto42]

Sounds good. Word of warning to the testers: I've never gotten the pingomatic call to actually work. I think this is a problem with pingomatic. But, since this is the current code, it's what I used for this patch.

The patch in ticket #4231 also has this code change, but also changes the update_links code to use RSS feeds to get the last updated time instead. That code actually works because it doesn't rely on pingomatic.

[Otto42]

Any traction on this? I really want something like this put into the core code. The patch may need to be refreshed at this point.

[Denis-de-Bernardy]

not even sure this is still current...

[dd32]

I've removed the Link update checking from core. This is better left for plugin material. See #12437