Thanks for the hints! I will try the plugin, and will experiment on localhost or some testing WP installation.
WP internals and studying
I was occupied in web development in the past, but since lost proficiency. Technologies moved forward significantly. The amount of new opportunities is overwhelming.
Mats, why, by the way, you’ve chosen the WP in the first place? Why not Drupal, Laravel, JS (full stack pack) or something else?
I’ve found the book you’ve mentioned. The book seems promising. I will try it. Thanks for the advice, again!
As to the codex.www.remarpro.com or developer.www.remarpro.com — yes, they have a lot of information. But I can not find there a WP architecture or data base structure (data model). It complicates studying process (at least for me).
DB tweaking
I’m looking at DB, and see it like this.
The relevant information about taxonomies is stored in the tables:
terms — name and slug info for all terms;
term_taxonomy — tree hierarchy is defined here, and also term2taxonomy relation (field taxonomy).
/* I wonder, why fields description and count are placed here, but not in the terms table? And why taxonomy defined as a string (slug?), but not as ID number? */
Also I see, that info about categories’ hierarchies saved in the table
options — there is a record with the option_name == category_children, which keep all (?) the parent2child relations for categories in serialized manner (probably, for speed improvement purposes? Probably, some WP functions do it automatically).
So, I guess, minimal set of actions for moving branch from Categories to a Custom Taxonomies manually through changing DB directly should be:
- To find all records for moving terms in table term_taxonomy and to change field taxonomy from ?category? to newly created Custom Taxonomy slug (for example, ?industry?);
- To find in the same table the root term for moved branch and to change its parent field into 0 (if it is not);
- To move the moved branch from the record option_name == category_children of options table to record option_name == industry_children.
Is it correct?
/* I wonder, why there is no separate table for taxonomies description? Why taxonomies addressed by slug/name but not by ID? And where all the information about the taxonomies (core and custom ones) is stored? For custom taxonomies, I guess, it stored in the options table. But where is the description of Categories and Tags taxonomies? */
Possible challenges
?One thing to consider how ever you do it is how to handle the change of url to taxonomy pages if this is indexed by search engines or linked to.?
Yes, that could be a problem. If web site has a history. Some external and internal links could be broken. On the other hand, the problem lays mainly on the SEO part. Any content restructuring activities, which sometimes inevitable, may lead to broken links. And SEO plugins have Redirection functionality because of that. The good one should have: automatic detection of broken links, bulk actions, rules implementation, etc.
In my situation it is desirable outcome, if all the overpopulated Categories just disappear (turn to hidden Custom Taxonomies). Shouldn’t be created in such way (as indexed Categories) from the start.
There may be one more problem with moving terms. Other plugins, themes and functions may use category links and save the information in DB. I see multiple records in the table postmeta, which directly related to category. I guess, it’s something about Menu and some menu may be broken in result. I also see the category links in a some_theme_options record in table options (in my case the old theme isn’t used anymore, but as a possibility).
Yep, the challenge it is. )
