Glossary

These terms are used throughout the manual. Each entry gives the working meaning and links to the chapter that defines the term fully.

Action — A named command defined with etaf-action-define and invoked with etaf-dispatch; it receives the Runtime as its first argument. Actions, Behaviors and Error Boundaries
animation — A timed interpolation of View or Host values driven by the Runtime's clock. Animation
batch — A form that groups reactive writes so the Runtime commits once when it ends. Reactivity
Behavior — A reusable set of non-visual Host properties plus an optional installer that returns a cleanup function. Actions, Behaviors and Error Boundaries
Box — The Host that establishes a block formatting context and lays its children out in normal flow. Boxes and Normal Flow
cascade — The ordered resolution of declarations from different origins, layers and selectors into one computed value. Style System
commit — One publication of a Runtime's changed output into its buffer during a drain. Reactivity
Component — A named, reusable View unit with props, defined with etaf-define-component; each use is an instance. Components
computed style — The final value of every style property after the cascade and inheritance. Style System
computed value — A reactive value derived from other reactive values and cached until a dependency changes. Reactivity
Context — A value an ancestor provides with etaf-provide and descendants read with etaf-inject. Context
Data Controller — The object that drives a Data Source, holds its items and status, and publishes them reactively. Data Controllers
Data Source — The record contract for loading, paging and mutating application data. Data Sources
drain — The loop that runs queued effects until reactive state settles, committing each changed Runtime once. Reactivity
Ebox — The engine package that keeps a retained box tree, lays it out and writes it into a buffer incrementally. Rendering Model
Ebox node — The retained unit of the layout tree; a Host owns one in a mounted Runtime. Node Construction
ecss — The cascade engine behind ETAF styles, usable as a general library. Selectors
effect — A reactive computation that reacts to the state it reads; a Scope owns it. Reactivity
ekp — Knuth–Plass paragraph line breaking with CJK support, usable standalone. Principles
error boundary — A Component clause that renders a fallback when its subtree fails. Actions, Behaviors and Error Boundaries
ETAF — The application framework this manual documents: Views, Hosts, Components, reactive state, Context, Runtimes, events, Behaviors, Actions, Resources and Data. Ecosystem and Layers
Event — An interaction delivered to a Host event property such as :on-press or :on-drag. Events
focus — The Host that receives framework keys, activation and the direction keys. Focus
Host — A node kind ETAF renders directly through Ebox: text, box, fragment, row, column, flex, grid and image. Hosts
Host reference — The stable handle by which a mounted Runtime addresses a committed Host. Hosts
input session — The editing state that turns one laid-out text node into an editable value. Text Input
instance — One use of a Component in a mounted View, with its own props, state and Scope. Components
key scope — The Hosts and their ancestors whose :keys entries can answer the current key. Keyboard
kinsoku — The rules that forbid certain CJK characters from starting or ending a line. CJK Typesetting
layer — A named cascade bucket that orders declarations before selector specificity. Stylesheets and Scopes
measure — The available width or height for paragraph layout, in pixels or characters. Principles
mount — The binding between an Ebox tree or ETAF Runtime and a buffer, kept consistent across updates. Mount and Lifecycle
normal flow — The default block and inline arrangement of boxes before positioning. Boxes and Normal Flow
origin — Where a declaration came from: an inline style, an author stylesheet, a user agent sheet or a rule file. Stylesheets and Scopes
performance recorder — The public measurement subsystem behind the etaf-performance-* interfaces. Performance Engineering
positioning — Off-flow placement of a Host relative to its containing block. Positioning, Layers and Overlays
preedit — Text an input method is composing but has not committed; it never enters the session value. Text Input
props — The declared inputs of a Component, with defaults and optional validation. Components
protrusion — Letting closing CJK punctuation hang into the margin instead of forcing a loose line. CJK Typesetting
reconciliation — The Data Controller policy that keeps optimistic writes and provider results convergent. Reconciliation
ref — The reactive cell that holds state and notifies its readers. Reactivity
region — A declared navigation area with an entry point, used by region navigation and the selector. Region Navigation
Resource — A value loaded asynchronously with status, reload and disposal. Resources
retained update — A publication path that writes content or geometry to committed Hosts by reference. Incremental Updates and Publication
Runtime — The object that etaf-mount creates for a buffer: it renders the View, owns the instance tree and commits changes. Runtime
Scope (ECSS) — The attachment point that binds a stylesheet to a subject tree. Stylesheets and Scopes
Scope (reactive) — The owner of effects that releases them together. Reactivity
selector — The pattern by which a rule matches Hosts through their metadata and classes. Selectors
semantic property — A Host property such as :role or :aria-label that describes meaning rather than paint or geometry. Hosts
slot — A named child position of a Component. Components
specificity — The weight of a selector, used to order declarations of the same origin and layer. Selectors
style property — A property Ebox uses for layout and painting, such as :padding or :font-weight. Style Properties
stylesheet — A set of rules created from ECSS sources and attached to a Scope. Stylesheets and Scopes
Theme — The map from tokens to style values that restyles a subtree. Component Styles and Themes
token — A named Theme value such as :ui-fg. Component Styles and Themes
View — An immutable description of user interface: a tree of Host and Component nodes. Views
viewport — The window-sized visible area of a rendered document. Viewport