Coverage for gws-app/gws/plugin/qgis/__init__.py: 0%

1"""QGIS support. 

2 

3The QGIS plugin supports parsing and writing QGIS projects, stored in paths or in a Postgres database. 

4The parsing is based on directly reading project XML files; no QGIS APIs are used. 

5The projects are parsed into capabilities objects, from which QGIS-based layers and finders can be created. 

6The rendering of QGIS layers is achieved by sending requests to a QGIS Server instance. 

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9Project and layer extents 

10------------------------- 

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12QGIS does not provide a way to obtain complete project and layer extents, with respect to symbology. 

13Only data-based extents are known at parse time. We compute extents with the following logic: 

14 

15- if a project provides an explicit WMS extent (Project Properties->QGIS Server->WMS), this extent is used as project render extent (`bounds`) 

16- otherwise, if `useCanvasExtent` is true, the canvas extent is used 

17- otherwise, the project render extent is set to the union of layers' data extents + the configured `extentBuffer` 

18- if the render extent is empty, the CRS extent is taken 

19- for layers, the data extent is either an explicit extent (Layer Properties->Metadata->Extent) or an implicit data extent 

20- the layer data extent is used as a "zoom" extent, but when rendering a layer, the project extent is used 

21""" 

22 

23from . import provider, project, caps