Standard Errors

The error conditions are part of the public API: a program that calls the framework catches them to tell a bad input from a missing mount or an unavailable backend, and to recover without leaving a partial state behind. This appendix lists every condition with its parent and the situation that raises it; the linked entries give the data each condition carries, the messages and what remains after a failure. Every condition derives from error except ebox-input-cancelled, which derives from quit so that ordinary error handlers do not intercept an abandoned input session.

ETAF

Condition	Parent	Signaled when
`etaf-view-error`	`error`	The base condition for an invalid View; the View and Component conditions below are its subtypes.
`etaf-view-syntax-error`	`etaf-view-error`	A structural form is malformed; raised while `etaf-view` expands, before any evaluation happens.
`etaf-component-definition-error`	`etaf-view-error`	A Component definition is invalid, or a Component API is used outside its phase.
`etaf-component-call-error`	`etaf-view-error`	A Component call or one of its inputs is invalid.
`etaf-renderer-error`	`error`	A normalized View cannot be shown, or a mounted Runtime is required but absent.
`etaf-reactive-error`	`error`	The reactive graph rejected an operation, such as a write during a computation or an invalid reactive value.
`etaf-render-side-effect-error`	`etaf-reactive-error`	An operation that would change the reactive graph was attempted during rendering; the data names the operation.
`etaf-runtime-error`	`error`	A Runtime operation cannot complete: use without a mount, malformed mount options or a failed retained update.
`etaf-observer-error`	`error`	Observer context state is built or used with an invalid value, such as a non-function sink.
`etaf-context-error`	`error`	A Context operation is malformed or a required dependency is missing.
`etaf-action-error`	`error`	An Action cannot be defined, registered or dispatched.
`etaf-behavior-error`	`error`	A Behavior spec, source, installer or controlled geometry input is invalid.
`etaf-event-error`	`error`	An event operation has an invalid event context or target.
`etaf-async-error`	`etaf-reactive-error`	An asynchronous adapter or timeout is invalid.
`etaf-async-timeout`	`etaf-async-error`	An asynchronous wait exceeded its timeout.
`etaf-async-cancelled`	`etaf-async-error`	Pending asynchronous work was cancelled.
`etaf-resource-error`	`etaf-reactive-error`	A Resource operation is invalid.
`etaf-data-error`	`error`	A Data contract is violated: a mutation is already pending, a batch is malformed, a capability is missing or an outcome is not committed.
`etaf-data-stopped-error`	`etaf-data-error`	An operation was attempted on a stopped Data Controller.
`etaf-animation-error`	`error`	An animation operation is invalid.

Ebox

Condition	Parent	Signaled when
`ebox-error`	`error`	A public entry point received input it cannot use: an unknown tag, a malformed author form, an invalid property list or a bad node topology.
`ebox-size-error`	`error`	A size value is outside its domain.
`ebox-style-schema-error`	`error`	A style schema is malformed.
`ebox-input-error`	`ebox-error`	An input session operation is invalid.
`ebox-input-cancelled`	`quit`	The input target is no longer available; its parent is `quit`, so an ordinary `error` handler does not catch it.

ECSS

Condition	Parent	Signaled when
`ecss-error`	`error`	The base condition for a rejected ECSS operation; the five conditions below are its subtypes.
`ecss-invalid-selector`	`ecss-error`	The selector grammar or a selector AST is invalid.
`ecss-invalid-subject-adapter`	`ecss-error`	A subject adapter cannot be built.
`ecss-invalid-property-schema`	`ecss-error`	A package or property definition is malformed, or a composition cannot be formed.
`ecss-invalid-declaration`	`ecss-error`	A declaration cannot be used as written.
`ecss-invalid-rule`	`ecss-error`	A rule, an origin, a layer or a source combination is invalid.

EKP

Condition	Parent	Signaled when
`ekp-hyphen-error`	`error`	The base condition for hyphenation failures; the two conditions below are its subtypes.
`ekp-hyphen-dictionary-not-found`	`ekp-hyphen-error`	No dictionary matches the requested language.
`ekp-hyphen-unsupported-pattern`	`ekp-hyphen-error`	A dictionary uses replacement patterns this implementation does not support.
`ekp-backend-contract-error`	`error`	The native backend returned a malformed result.

ETAF UI

Condition	Parent	Signaled when
`etaf-ui-svg-error`	`error`	The SVG scene helpers received invalid input.
`etaf-ui-markdown-error`	`error`	A markdown operation was rejected: an unknown dialect name during parsing, or a missing palette or unknown palette key during rendering.

ETAF DB

Condition	Parent	Signaled when
`etaf-sqlite-error`	`error`	The base condition for a rejected SQLite operation; the three conditions below are its subtypes.
`etaf-sqlite-schema-error`	`etaf-sqlite-error`	A descriptor or an initialized database does not match the declared schema.
`etaf-sqlite-unavailable`	`etaf-sqlite-error`	The Emacs build has no SQLite support.
`etaf-sqlite-commit-unknown`	`etaf-sqlite-error`	A mutation's commit outcome cannot be determined.