Interface SelectUserDataOptions

List of predicate functions that must all return true for updates to be emitted.

Filters are evaluated after map transformations. If any filter returns false, the callback is not invoked for that state change. Useful for preventing unnecessary updates. Functions are bound to the web component instance.

Example

filter: [
    (state) => state !== null,              // Ignore null states
    (state) => state.isReady,               // Only when ready
    (state) => state.items.length > 0       // Only when has items
]

Key specifying the user data

List of transformation functions applied sequentially to the state.

Each function receives the output of the previous function (or the raw state for the first function). Use this to extract, transform, or compute derived values from the state. Functions are bound to the web component instance.

Example

map: [
    (state) => state.orders,                    // Extract orders
    (orders) => orders.filter(o => o.pending),  // Filter to pending only
    (pending) => pending.length                 // Get count
]
// Callback receives: number (count of pending orders)