27.10. Input and output types for Processing Algorithms

Here is the list of input and output types that are supported in Processing with their corresponding alg decorator constants, their name in the modeler designer if exposed.

27.10.1. Input types

Input name	Class	Alg constant	Description
Annotation layer	QgsProcessingParameterAnnotationLayer	alg.ANNOTATION_LAYER	An annotation layer
Authentication Configuration	QgsProcessingParameterAuthConfig	alg.AUTH_CFG	Allows users to select from available authentication configurations or create new authentication configurations
Raster band	QgsProcessingParameterBand	alg.BAND	A band of a raster layer
Boolean	QgsProcessingParameterBoolean	alg.BOOL	A boolean value
Connection Name	QgsProcessingParameterProviderConnection		A selection from available registered connections for a particular data provider
Color	QgsProcessingParameterColor	alg.COLOR	A color
Coordinate Operation	QgsProcessingParameterCoordinateOperation	alg.COORDINATE_OPERATION	A coordinate operation (for CRS transformations)
CRS	QgsProcessingParameterCrs	alg.CRS	A Coordinate Reference System
Database Schema	QgsProcessingParameterDatabaseSchema	alg.DATABASE_SCHEMA	A database schema
Database Table	QgsProcessingParameterDatabaseTable	alg.DATABASE_TABLE	A database table
Datetime	QgsProcessingParameterDateTime	alg.DATETIME	A datetime (or a pure date or time)
Distance	QgsProcessingParameterDistance	alg.DISTANCE	A double numeric parameter for distance values
DXF Layers	QgsProcessingParameterDxfLayers		A list of vector layers to export as DXF file
Enum	QgsProcessingParameterEnum	alg.ENUM	An enumeration, allowing for selection from a set of predefined values
Expression	QgsProcessingParameterExpression	alg.EXPRESSION	An expression
Extent	QgsProcessingParameterExtent	alg.EXTENT	A spatial extent defined by xmin, xmax, ymin, ymax
	QgsProcessingParameterField	alg.FIELD	A field in the attribute table of a vector layer
Field Aggregates	QgsProcessingParameterAggregate		A parameter for “aggregate” configurations, which consist of a definition of desired output fields, types, and aggregate used to populate them
Fields Mapper	QgsProcessingParameterFieldMapping		A parameter for “field mapping” configurations, which consist of a definition of desired output fields, types, and expressions used to populate them
File/Folder	QgsProcessingParameterFile	alg.FILE	A filename of an existing file
	QgsProcessingParameterFileDestination	alg.FILE_DEST	A filename for a newly created output file
	QgsProcessingParameterFolderDestination	alg.FOLDER_DEST	A folder (destination folder)
Geometry	QgsProcessingParameterGeometry	alg.GEOMETRY	A geometry
	QgsProcessingParameterNumber.Integer	alg.INT	An integer
Print Layout	QgsProcessingParameterLayout	alg.LAYOUT	A layout
Print Layout Item	QgsProcessingParameterLayoutItem	alg.LAYOUT_ITEM	A layout item
Map Layer	QgsProcessingParameterMapLayer	alg.MAPLAYER	A map layer
Map Theme	QgsProcessingParameterMapTheme	alg.MAP_THEME	A project map theme
Matrix	QgsProcessingParameterMatrix	alg.MATRIX	A matrix
Mesh Dataset Groups	QgsProcessingParameterMeshDatasetGroups		Dataset groups of mesh layer
Mesh Dataset Time	QgsProcessingParameterMeshDatasetTime		Dataset index from a mesh layer by time setting
Mesh Layer	QgsProcessingParameterMeshLayer	alg.MESH_LAYER	A mesh layer
Multiple Input	QgsProcessingParameterMultipleLayers	alg.MULTILAYER	A set of layers
Number	QgsProcessingParameterNumber.Double	alg.NUMBER	A numerical value
Point	QgsProcessingParameterPoint	alg.POINT	A point
Point Cloud Attribute	QgsProcessingParameterPointCloudAttribute		An attribute from a point cloud layer
	QgsProcessingParameterPointCloudDestination	alg.POINTCLOUD_LAYER_DEST	A point cloud layer destination parameter, for specifying the destination path for a point cloud layer created by the algorithm
Point Cloud Layer	QgsProcessingParameterPointCloudLayer	alg.POINTCLOUD_LAYER	A point cloud layer
	QgsProcessingParameterProviderConnection	alg.PROVIDER_CONNECTION	An available connection for a database provider
Range	QgsProcessingParameterRange	alg.RANGE	A number range
Raster Layer	QgsProcessingParameterRasterLayer	alg.RASTER_LAYER	A raster layer
	QgsProcessingParameterRasterDestination	alg.RASTER_LAYER_DEST	A raster layer destination parameter, for specifying the destination path for a raster layer created by the algorithm
Scale	QgsProcessingParameterScale	alg.SCALE	A map scale
	QgsProcessingParameterFeatureSink	alg.SINK	A feature sink
TIN Creation Layers	QgsProcessingParameterTinInputLayers		Selection of multiple layers to create a TIN with vertices and/or break lines
Vector Features	QgsProcessingParameterFeatureSource	alg.SOURCE	A feature source
String	QgsProcessingParameterString	alg.STRING	A text string
Vector Layer	QgsProcessingParameterVectorLayer	alg.VECTOR_LAYER	A vector layer
	QgsProcessingParameterVectorDestination	alg.VECTOR_LAYER_DEST	A vector layer destination parameter, for specifying the destination path for a vector layer created by the algorithm
Vector Tile Writer Layers	QgsProcessingParameterVectorTileDestination		A vector tile layer destination parameter, for specifying the destination path for a vector tile layer created by the algorithm

27.10.2. Output types

Class	Alg constant	Description
QgsProcessingOutputBoolean	alg.BOOL	A boolean value
QgsProcessingOutputNumber	alg.DISTANCE	A double numeric parameter for distance values
QgsProcessingOutputFile	alg.FILE	A filename of an existing file
QgsProcessingOutputFolder	alg.FOLDER	A folder
QgsProcessingOutputHtml	alg.HTML	HTML
QgsProcessingOutputNumber	alg.INT	A integer
QgsProcessingOutputLayerDefinition	alg.LAYERDEF	A layer definition
QgsProcessingOutputMapLayer	alg.MAPLAYER	A map layer
QgsProcessingOutputMultipleLayers	alg.MULTILAYER	A set of layers
QgsProcessingOutputNumber	alg.NUMBER	A numerical value
QgsProcessingOutputPointCloudLayer	alg.POINTCLOUD_LAYER	A point cloud layer
QgsProcessingOutputRasterLayer	alg.RASTER_LAYER	A raster layer
QgsProcessingOutputString	alg.STRING	A text string
QgsProcessingOutputVectorLayer	alg.VECTOR_LAYER	A vector layer
QgsProcessingOutputVectorTileLayer		A vector tile layer