Prefix Matching

In many great literary works (the House of Atreus, One Hundred Years of Solitude, the Old Testament), a curse is placed not only on the protagonist, but also on their progeny. That’s friggin’ awesome.

Tags work the same way. When you invalidate a tag, all “child” tags are also invalidated.

How It Works

TypeScript

const tags = defineTags({
  user: (id: string) => ['user', id],
  userPosts: (id: string) => ['user', id, 'posts'],
  userSettings: (id: string) => ['user', id, 'settings'],
});

// Invalidating tags.user('123') also invalidates:
// - ['user', '123']           ← exact match
// - ['user', '123', 'posts']  ← prefix match
// - ['user', '123', 'settings'] ← prefix match

Python

tags = define_tags({
    "user": lambda id: ("user", id),
    "user_posts": lambda id: ("user", id, "posts"),
    "user_settings": lambda id: ("user", id, "settings"),
})

# Invalidating tags["user"]("123") also invalidates:
# - ("user", "123")             ← exact match
# - ("user", "123", "posts")    ← prefix match
# - ("user", "123", "settings") ← prefix match

Exact Mode

If you only want to invalidate the exact tag:

TypeScript

return {
  invalidates: [tags.user(id)],
  exact: true, // Only invalidates ['user', '123'], not children
};

Python

return MutationResult(
    result=user,
    invalidates=[tags["user"](id)],
    exact=True,  # Only invalidates ("user", "123"), not children
)