Class: QgsJsonUtils

class qgis.core.QgsJsonUtils

Bases: sip.wrapper

Helper utilities for working with JSON and GeoJSON conversions.

Methods

encodeValue

Encodes a value to a JSON string representation, adding appropriate quotations and escaping where required.

exportAttributes

Exports all attributes from a QgsFeature as a JSON map type.

parseArray

Parse a simple array (depth=1)

stringToFeatureList

Attempts to parse a GeoJSON string to a collection of features.

stringToFields

Attempts to retrieve the fields from a GeoJSON string representing a collection of features.

encodeValue(value: Any) → str

Encodes a value to a JSON string representation, adding appropriate quotations and escaping where required.

Parameters

value (Any) – value to encode

Return type

str

Returns

encoded value

exportAttributes(feature: QgsFeature, layer: QgsVectorLayer = None, attributeWidgetCaches: Iterable[Any] = []) → str

Exports all attributes from a QgsFeature as a JSON map type.

Parameters
  • feature (QgsFeature) – feature to export

  • layer (QgsVectorLayer = None) – optional associated vector layer. If specified, this allows richer export utilising settings like the layer’s fields widget configuration.

  • attributeWidgetCaches (Iterable[Any] = []) – optional widget configuration cache. Can be used to speed up exporting the attributes for multiple features from the same layer.

Return type

str

parseArray(json: str, type: QVariant.Type = QVariant.Invalid) → List[Any]

Parse a simple array (depth=1)

Parameters
  • json (str) – the JSON to parse

  • type (QVariant.Type = QVariant.Invalid) – optional variant type of the elements, if specified (and not Invalid), the array items will be converted to the type, and discarded if the conversion is not possible.

New in version 3.0.

Return type

List[Any]

stringToFeatureList(string: str, fields: QgsFields = QgsFields(), encoding: QTextCodec = None) → List[QgsFeature]

Attempts to parse a GeoJSON string to a collection of features. It is possible to specify fields to parse specific fields, if not provided, no fields will be included. An encoding can be specified which defaults to UTF-8 if it is None.

Return type

List[QgsFeature]

Returns

a list of parsed features, or an empty list if no features could be parsed

See also

stringToFields()

Note

this function is a wrapper around QgsOgrUtils.stringToFeatureList()

Parameters
  • string (str) –

  • fields (QgsFields = QgsFields()) –

  • encoding (QTextCodec = None) –

stringToFields(string: str, encoding: QTextCodec = None) → QgsFields

Attempts to retrieve the fields from a GeoJSON string representing a collection of features. An encoding can be specified which defaults to UTF-8 if it is None.

Return type

QgsFields

Returns

retrieved fields collection, or an empty list if no fields could be determined from the string

Note

this function is a wrapper around QgsOgrUtils.stringToFields()

Parameters
  • string (str) –

  • encoding (QTextCodec = None) –