Class: QgsVectorTileLayer¶

Implements a map layer that is dedicated to rendering of vector tiles.

Vector tiles compared to “ordinary” vector layers are pre-processed data optimized for fast rendering. A dataset is provided with a series of zoom levels for different map scales. Each zoom level has a matrix of tiles that contain actual data. A single vector tile may be a a file stored on a local drive, requested over HTTP request or retrieved from a database.

Content of a vector tile is divided into one or more named sub-layers. Each such sub-layer may contain many features which consist of geometry and attributes. Contrary to traditional vector layers, these sub-layers do not need to have a rigid schema where geometry type and attributes are the same for all features. A single sub-layer may have multiple geometry types in a single tile or have some attributes defined only at particular zoom levels.

Vector tile layer currently does not use the concept of data providers that other layer types use. The process of rendering of vector tiles looks like this:

+--------+                +------+                 +---------+
|  DATA  |                |  RAW |                 | DECODED |
|        | --> LOADER --> |      | --> DECODER --> |         | --> RENDERER
| SOURCE |                | TILE |                 |  TILE   |
+--------+                +------+                 +---------+

Data source is a place from where tiles are fetched from (URL for HTTP access, local files, MBTiles file, GeoPackage file or others. Loader (QgsVectorTileLoader) class takes care of loading data from the data source. The “raw tile” data is just a blob (QByteArray) that is encoded in some way. There are multiple ways how vector tiles are encoded just like there are different formats how to store images. For example, tiles can be encoded using Mapbox Vector Tiles (MVT) format or in GeoJSON. Decoder (QgsVectorTileDecoder) takes care of decoding raw tile data into QgsFeature objects. A decoded tile is essentially an array of vector features for each sub-layer found in the tile - this is what vector tile renderer (QgsVectorTileRenderer) expects and does the map rendering.

To construct a vector tile layer, it is best to use QgsDataSourceUri class and set the following parameters to get a valid encoded URI:

“type” - what kind of data source will be used
“url” - URL or path of the data source (specific to each data source type, see below)

Currently supported data source types:

“xyz” - the “url” should be a template like http://example.com/{z}/{x}/{y}.pbf where {x},{y},{z} will be replaced by tile coordinates
“mbtiles” - tiles read from a MBTiles file (a SQLite database)

Currently supported decoders:

MVT - following Mapbox Vector Tiles specification

Added in version 3.14.

Class Hierarchy¶

Base classes¶

`QgsMapLayer`	Base class for all map layer types.
QObject

Methods

`isTileBorderRenderingEnabled`	Returns whether to render also borders of tiles (useful for debugging)
`labeling`	Returns currently assigned labeling
`labelsEnabled`	Returns whether the layer contains labels which are enabled and should be drawn.
`loadDefaultStyleAndSubLayers`	Loads the default style for the layer, and returns `True` if the style was successfully loaded.
`removeSelection`	Clear selection
`renderer`	Returns currently assigned renderer
`selectByGeometry`	Selects features found within the search geometry (in layer's coordinates).
`selectedFeatureCount`	Returns the number of features that are selected in this layer.
`selectedFeatures`	Returns the list of features currently selected in the layer.
`setLabeling`	Sets labeling for the map layer.
`setLabelsEnabled`	Sets whether labels should be enabled for the layer.
`setRenderer`	Sets renderer for the map layer.
`setTileBorderRenderingEnabled`	Sets whether to render also borders of tiles (useful for debugging)
`sourceMaxZoom`	Returns maximum zoom level at which source has any valid tiles (negative = unconstrained)
`sourceMinZoom`	Returns minimum zoom level at which source has any valid tiles (negative = unconstrained)
`sourcePath`	Returns URL/path of the data source (syntax different to each data source type)
`sourceType`	Returns type of the data source
`tileMatrixSet`	Returns the vector tile matrix set.

Signals

selectionChanged

Emitted whenever the selected features in the layer are changed.

class qgis.core.QgsVectorTileLayer[source]¶

Bases: QgsMapLayer

__init__(path: str | None = '', baseName: str | None = '', options: QgsVectorTileLayer.LayerOptions = QgsVectorTileLayer.LayerOptions())

Constructs a new vector tile layer

Parameters:

path (Optional[str] = '')
baseName (Optional[str] = '')
options (QgsVectorTileLayer.LayerOptions = QgsVectorTileLayer.LayerOptions())

class LayerOptions¶

Bases: object

Setting options for loading vector tile layers.

Added in version 3.22.

isTileBorderRenderingEnabled(self) → bool[source]¶

Returns whether to render also borders of tiles (useful for debugging)

Return type:: bool

labeling(self) → QgsVectorTileLabeling | None[source]¶

Returns currently assigned labeling

Return type:: Optional[QgsVectorTileLabeling]

labelsEnabled(self) → bool[source]¶

Returns whether the layer contains labels which are enabled and should be drawn.

Return type:: bool
Returns:: True if layer contains enabled labels

See also

setLabelsEnabled()

Added in version 3.34.

loadDefaultStyleAndSubLayers(self, error: str | None, warnings: Iterable[str | None])[source]¶

Loads the default style for the layer, and returns True if the style was successfully loaded. Also loads any sub layers (such as raster terrain layers) associated with the layer’s default style.

The error string will be filled with a translated error message if an error occurs during the style load. The warnings list will be populated with any warning messages generated during the style load (e.g. default style properties which could not be converted).

Ownership of the subLayers is transferrred to the caller.

Added in version 3.28.

Parameters:

error (Optional[str])
warnings (Iterable[Optional[str]]) -> (bool)

removeSelection(self)[source]¶: Clear selection

See also

selectByGeometry()

See also

selectionChanged()

Added in version 3.28.

renderer(self) → QgsVectorTileRenderer | None[source]¶

Returns currently assigned renderer

Return type:: Optional[QgsVectorTileRenderer]

selectByGeometry(self, geometry: QgsGeometry, context: QgsSelectionContext, behavior: Qgis.SelectBehavior = Qgis.SelectBehavior.SetSelection, relationship: Qgis.SelectGeometryRelationship = Qgis.SelectGeometryRelationship.Intersect, flags: Qgis.SelectionFlags | Qgis.SelectionFlag = Qgis.SelectionFlags(), renderContext: QgsRenderContext | None = None)[source]¶

Selects features found within the search geometry (in layer’s coordinates).

A render context can optionally be specified in order to avoid selecting features which are not currently rendered.

See also

selectedFeatures()

See also

removeSelection()

See also

selectionChanged()

Added in version 3.28.

Parameters:

geometry (QgsGeometry)
context (QgsSelectionContext)
behavior (Qgis.SelectBehavior = Qgis.SelectBehavior.SetSelection)
relationship (Qgis.SelectGeometryRelationship = Qgis.SelectGeometryRelationship.Intersect)
flags (Union[Qgis.SelectionFlags, Qgis.SelectionFlag] = Qgis.SelectionFlags())
renderContext (Optional[QgsRenderContext] = None)