@terascope/data-mate / teal-frame/export-json

teal-frame/export-json

Interfaces

Interface	Description
JsonExportOptions	How an export renders fields and nulls: DataFrame's SerializeOptions, with the same meaning, plus removeNullFields as a shorthand for two common presets. See resolveRules.

Functions

buildJsonExpression()

buildJsonExpression(config, options?): string

Defined in: data-mate/src/teal-frame/export-json.ts:475

A SQL expression producing one JSON string per row, byte-identical to DataFrame.toJSON with the same options, or NULL for a row that skipEmptyObjects drops.

Two things are left to the caller: removing duplicate rows under skipDuplicateObjects, which compares whole rendered rows in order and is done on the stream (TealFrame.ndjson), and filtering rows, which uses buildJsonRowFilter.

Parameters

Parameter	Type
config	DataTypeConfig | Readonly<Overwrite<DataTypeConfig, { fields: ReadonlyDataTypeFields; }>>
options	JsonExportOptions

Returns

string

---

buildJsonListElements()

buildJsonListElements(config, column, options?): object

Defined in: data-mate/src/teal-frame/export-json.ts:440

SQL rendering one LIST column's elements as JSON text (see TealFrame.listValues), and whether the elements are objects, which decides whether skipNilObjectValues applies.

Parameters

Parameter	Type
config	DataTypeConfig | Readonly<Overwrite<DataTypeConfig, { fields: ReadonlyDataTypeFields; }>>
column	string
options	JsonExportOptions

Returns

object

isObject

isObject: boolean

sql

sql: string

---

buildJsonRowFilter()

buildJsonRowFilter(config, options?): string | undefined

Defined in: data-mate/src/teal-frame/export-json.ts:459

The predicate for the rows an export writes, or undefined when it writes all of them. It is separate from buildJsonExpression so the filter never evaluates the rendered row.

Parameters

Parameter	Type
config	DataTypeConfig | Readonly<Overwrite<DataTypeConfig, { fields: ReadonlyDataTypeFields; }>>
options	JsonExportOptions

Returns

string | undefined

---

resolveRules()

resolveRules(options?): Rules

Defined in: data-mate/src/teal-frame/export-json.ts:170

Resolves the rules an export follows.

If any SerializeOptions flag is given, the flags mean exactly what they mean to DataFrame.toJSON, and an unset flag is false. removeNullFields selects a preset that explicit flags override. With neither, the default is the removeNullFields: true preset.

Parameters

Parameter	Type
options	JsonExportOptions

Returns

Rules