Skip to content

Parse Context⚓︎

context ⚓︎

Context objects passed through table and cell parsing.

Contexts keep project-owned dependencies separate from schema declarations. They are immutable containers passed through transformers, parsers, default factories, and validation hooks during one parse operation.

Info

talika copies user mappings into read-only views so parser code can read dependencies without accidentally mutating caller-owned state.

ParseContext dataclass ⚓︎

ParseContext(user_data: Mapping[str, Any] = (lambda: MappingProxyType({}))())

Project-owned dependencies and settings for one parse operation.

The library copies the supplied mapping and exposes it as read-only user_data. Cell parsers, table transformers, and record validators all receive data originating from this same context object.

Attributes:

  • user_data (Mapping[str, Any]) –

    Read-only mapping of project-owned dependencies and settings.

Example

UserTable.parse(datatable, context={"faker": faker})

from_value classmethod ⚓︎

from_value(value: Mapping[str, Any] | ParseContext | None) -> ParseContext

Normalize raw context input.

Parameters:

Returns:

  • ParseContext –

    A ParseContext instance with read-only user_data.

Raises:

  • TypeError –

    If value cannot be copied as a mapping.

Info

Existing ParseContext objects pass through unchanged, which lets advanced callers construct and reuse immutable context values.

CellContext dataclass ⚓︎

CellContext(
    schema: type,
    field_name: str,
    field_label: str,
    row: int | None,
    column: int | None,
    item_id: Any | None,
    source_value: str,
    user_data: Mapping[str, Any],
    source_uri: str | None = None,
)

Source location and project data supplied to a field parser.

value is passed separately to a field parser and represents the current, possibly transformed value. source_value records what was written in the original Gherkin data table before table transformation.

Attributes:

  • schema (type) –

    Concrete schema class parsing the cell.

  • field_name (str) –

    Python attribute name receiving the parsed value.

  • field_label (str) –

    Canonical Gherkin data table label for the field.

  • row (int | None) –

    One-based source row when available.

  • column (int | None) –

    One-based source column when available.

  • item_id (Any | None) –

    Parsed record ID when available.

  • source_value (str) –

    Original feature-file text before transformation.

  • user_data (Mapping[str, Any]) –

    Read-only project data from ParseContext.

  • source_uri (str | None) –

    URI of the source document when known.

Warning

Parser functions receive the current value as a separate argument. Use source_value only when diagnostics or project syntax need the original feature text.

DefaultContext dataclass ⚓︎

DefaultContext(
    schema: type,
    field_name: str,
    field_label: str,
    item_id: Any | None,
    user_data: Mapping[str, Any],
    source_uri: str | None = None,
)

Context supplied when a missing optional field uses a factory.

Default factories do not have a source cell because the field was omitted from the Gherkin data table. They still receive the selected schema, field identity, item ID when available, and the same read-only project data supplied to the parse operation.

Attributes:

  • schema (type) –

    Concrete schema class building the default.

  • field_name (str) –

    Python attribute name receiving the default.

  • field_label (str) –

    Canonical Gherkin data table label for the field.

  • item_id (Any | None) –

    Parsed record ID when available.

  • user_data (Mapping[str, Any]) –

    Read-only project data from ParseContext.

  • source_uri (str | None) –

    URI of the source document when known.

Info

Default factories run only for missing optional fields, not for explicit empty cells.