The subscribe request

The add-on uses two endpoints of the Wereldkundig API. The full API is documented at docs.wereldkundig.nl/api.

• Base URL: {platform}/wp-json/wereldkundig, changeable with wk_api_base_url.
• Every request sends the Basic Auth header and JSON, and waits at most 10 seconds (wk_api_timeout).

GET /v1/subscribe/fields

Returns the subscriber fields and the platform’s themes, each with categories and child categories. This answer is what the add-on caches.

Theme IDs are always written as theme-{id}: 1, theme-1 and theme_1 all become theme-1.

POST /v1/subscribe

Subscribes one person to all chosen themes, in one request:

{
  "email": "[email protected]",
  "first_name": "Jan",
  "last_name": "Jansen",
  "options": { "theme-1": true, "category-36-37": true, "category-36-38": true }
}

• options holds a whole theme as theme-{id}, or only the chosen categories of a theme as the platform’s category keys: category-{id}, category-{parent}-{id} for a child category, or select-all-{id} for everything in a parent category.
• Chosen categories are sent without their theme; the platform adds the theme itself. Sending the theme as well would subscribe to the whole theme.
• email is always sent. Other fields are only sent when they have a value, so an empty field can’t clear a value stored on the platform.
• Field keys must match [a-z0-9_]+. Values that aren’t text or numbers are left out.
• The platform’s answer contains the platform user_id and any rejected_options. Both appear in the entry note.

The fields come from wk_gf_subscriber_pre_subscribe and the themes from wk_gf_subscribe_themes: theme ID => category keys, an empty array meaning the whole theme.