Option
access of table
Who may read, add, change and remove rows.
Value
{ read, add, change, remove }, each a rule. A rule that is left out means 'nobody'.
A rule of 'signedIn' is worth what the app's own sign-up lets in: where anyone may sign up, it lets in anyone who cares to. The engine holds no sign-up of its own, so who may make an account is the code of the project (topic.signIn).
A rule made with where lets a caller reach the rows that fit its filter, for a write as for a read. add holds the new row against the filter of the add rule: the row is added where it fits, and refused with code.T3101 where it does not. change and remove first find the row with the rule as a filter: a row that does not fit is not found for the caller, and the call fails. So a caller writes the rows that the filter gives them, and no other, with no system and no check by hand.
A change that states system and writes through db.system passes every rule, and holds nothing against the caller but what its code checks. Where a rule can say who may write a row, write it with the rule, and keep system for what no rule can say. tent check reports a change open to callers that skips the rules of a row it names, with no check of the caller against it, as code.T3009.
Example
export const orders = table('orders', {
columns: { team: link('teams', { onRemove: 'remove' }), placedBy: link('users'), note: text({ optional: true }), total: number() },
access: { read: where({ placedBy: 'u1' }), add: 'signedIn', change: 'owner', remove: role('staff') },
})
// A renter tells of their own rents alone: the rule finds the row, and refuses every other.
export const rents = table('rents', {
columns: { renter: link('users'), month: text(), status: choice(['due', 'told', 'paid']) },
access: { read: where({ renter: caller('id') }), change: where({ renter: caller('id') }) },
})