get_term_by( 'term_taxonomy_id' ) should NOT require $taxonomy param

[joehoyle]

As we all despise term_ids as it requires a id / taxonomy name pair, it's often nicer to use term_taxonomy_id as it's a much better identifier. This *should* mean it's not necessary to know the taxonomy of a given tt_id (just like one doesn't need to know the post_type of a post to get a post from ID). However, the $taxonomy param to get_term_by() is required.

It seems to be it would be good to change $taxonomy to be not required in the cases of getting by tt_id with get_term_by().

I'll write the code if anyone agrees this makes sense :)

Apologies if that has ben addresses, I'm a bit out of the loop recently.

[theMikeD]

Given <​https://make.wordpress.org/core/2013/07/28/potential-roadmap-for-taxonomy-meta-and-post-relationships/> and <​https://make.wordpress.org/core/2014/11/12/an-update-on-the-taxonomy-roadmap/> I think this is already underway :)

[SergeyBiryukov]

Introduced in [25334].

[helen]

It appears I agreed with this a while ago, wonderboymusic pointed out that we should mind the cache (see #21760).

[wonderboymusic]

30620.diff​ - we would probably need to add tt_ids to a cache that is does not have tax in its group hash

[wonderboymusic]

If the spirit moves you

[boonebgorges]

In 34679:

Don't require explicit taxonomy when getting terms by term_taxonomy_id.

Props wonderboymusic.
Fixes #30620.

[rmccue]

FYI, this change to get_term_by ​broke the REST API, since we relying on the check. We've fixed it, but might be worth noting in a field notes post for others that it might break.

(Accidentally commented on #14162, but that's unrelated.)

[boonebgorges]

Replying to rmccue:

FYI, this change to get_term_by ​broke the REST API, since we relying on the check. We've fixed it, but might be worth noting in a field notes post for others that it might break.

(Accidentally commented on #14162, but that's unrelated.)

Thanks for the note. I'll note the change in the taxonomy field notes for 4.4. But the new behavior is probably the correct one: if you are passing a 'term_taxonomy_id', you're likely doing it for the explicit reason that you want to avoid the 'taxonomy' table join, which means that you've already done your homework.