Glossary

The vocabulary used throughout these docs.

Structure

App: A collection of pages and shared resources.

Page: An element tree connected to a route in an app.

Element: One node in a page or component tree. It has a kind, props, styles, and children.

Tree: Elements arranged as parents and children. A subtree is an element and its descendants.

Kind: The primitive or component an element renders.

Primitive: A supplied building block. Primitive elements form component trees; primitive functions form action chains.

Registry: The catalog of supplied element kinds and the props they accept.

Component: A reusable element tree with an interface for its props.

Instance: One use of a component, with its own prop values and component state.

Repeat: A subtree rendered once for each item in an array.

Conditional rendering: A condition that determines whether an element and its subtree appear.

One Card component can have two instances, each with a different title.

State: The current values used by an app, page, or component.

Store: A named collection of state fields and actions, scoped to an app, page, or component.

Scope: Where a store or hook is available: an app, page, or component. A hook can be shared across selected pages.

Prop: A named value supplied to an element or component.

Field: A named declaration with a type and an optional default value.

Type: The values a field accepts, such as Text, Number, or Boolean.

Interface: A list of fields describing a set of named values, such as component props or function inputs.

Schema: A named interface that can be reused within an app.

Expression: A value computed from the current context, such as {{stores.counter.count}}.

Binding: A reference to a component, element, function, or file. Component bindings can supply props; function bindings can supply arguments.

A field declares title: Text. A prop supplies title: "Hello". An expression computes a value. A binding selects a target.

Event: An interaction or change, such as a click or an input value changing.

Function: A callable operation with inputs and an optional output. A binding can call a primitive function, an action, or a hook method.

Action: A named, reusable chain of function calls on a store. Calls run in order; the last call supplies the result.

Parameter: A declared input to a function or action.

Argument: A value supplied for a parameter when a function or action is called.

Hook: Configured behavior that provides values or methods, such as form state, query results, or a reference.

Render prop: A callback whose result is an element subtree. Its inputs are available to that subtree through render expressions.

A button's onClick prop can bind to an action. The action calls functions to update state or navigate.