Attempt to fix doctests by using airports layer in epsg4326 instead o…

…f epsg2964 (#9432)

Backport #9256

docs/pyqgis_developer_cookbook/canvas.rst

@@ -123,7 +123,7 @@ layers for the canvas.
 
 .. testcode:: canvas
 
-  vlayer = QgsVectorLayer('testdata/airports.shp', "Airports layer", "ogr")
+  vlayer = QgsVectorLayer("testdata/data/data.gpkg|layername=airports", "Airports layer", "ogr")
   if not vlayer.isValid():
       print("Layer failed to load!")
 
@@ -136,11 +136,6 @@ layers for the canvas.
   # set the map canvas layer set
   canvas.setLayers([vlayer])
 
-.. testoutput:: canvas
-   :hide:
-
-   (2): Using non-preferred coordinate operation between EPSG:2964 and EPSG:4326. Using +proj=pipeline +step +proj=unitconvert +xy_in=us-ft +xy_out=m +step +inv +proj=aea +lat_0=50 +lon_0=-154 +lat_1=55 +lat_2=65 +x_0=0 +y_0=0 +ellps=clrk66 +step +proj=push +v_3 +step +proj=cart +ellps=clrk66 +step +proj=helmert +x=-5 +y=135 +z=172 +step +inv +proj=cart +ellps=WGS84 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg, preferred +proj=pipeline +step +proj=unitconvert +xy_in=us-ft +xy_out=m +step +inv +proj=aea +lat_0=50 +lon_0=-154 +lat_1=55 +lat_2=65 +x_0=0 +y_0=0 +ellps=clrk66 +step +proj=hgridshift +grids=us_noaa_alaska.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg.
-
 After executing these commands, the canvas should show the layer you have
 loaded.
 

docs/pyqgis_developer_cookbook/cheat_sheet.rst

@@ -168,7 +168,7 @@ Layers
 
 .. testcode:: cheat_sheet
 
-    layer = iface.addVectorLayer("testdata/airports.shp", "layer name you like", "ogr")
+    layer = iface.addVectorLayer("testdata/data/data.gpkg|layername=airports", "Airports layer", "ogr")
     if not layer or not layer.isValid():
         print("Layer failed to load!")
 

docs/pyqgis_developer_cookbook/loadlayer.rst

@@ -48,55 +48,33 @@ them here.
 Vector Layers
 =============
 
-To create and add a vector layer instance to the project, specify the layer's data source
-identifier, name for the layer and provider's name:
-
-.. testcode:: loadlayer
-
- # get the path to the shapefile e.g. /home/project/data/ports.shp
- path_to_airports_layer = "testdata/airports.shp"
-
- # The format is:
- # vlayer = QgsVectorLayer(data_source, layer_name, provider_name)
-
- vlayer = QgsVectorLayer(path_to_airports_layer, "Airports layer", "ogr")
- if not vlayer.isValid():
-     print("Layer failed to load!")
- else:
-     QgsProject.instance().addMapLayer(vlayer)
-
-.. .. testoutput:: loadlayer
-   :hide:
-
-   (2): Using non-preferred coordinate operation between EPSG:2964 and EPSG:4326. Using +proj=pipeline +step +proj=unitconvert +xy_in=us-ft +xy_out=m +step +inv +proj=aea +lat_0=50 +lon_0=-154 +lat_1=55 +lat_2=65 +x_0=0 +y_0=0 +ellps=clrk66 +step +proj=push +v_3 +step +proj=cart +ellps=clrk66 +step +proj=helmert +x=-5 +y=135 +z=172 +step +inv +proj=cart +ellps=WGS84 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg, preferred +proj=pipeline +step +proj=unitconvert +xy_in=us-ft +xy_out=m +step +inv +proj=aea +lat_0=50 +lon_0=-154 +lat_1=55 +lat_2=65 +x_0=0 +y_0=0 +ellps=clrk66 +step +proj=hgridshift +grids=us_noaa_alaska.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg.
-
-The data source identifier is a string and it is specific to each vector data
-provider. Layer's name is used in the layer list widget. It is important to
-check whether the layer has been loaded successfully. If it was not, an invalid
-layer instance is returned.
+To create and add a vector layer instance to the project, specify the layer's data source identifier.
+The data source identifier is a string and it is specific to each vector data provider.
+An optional layer name is used for identifying the layer in the :guilabel:`Layers` panel.
+It is important to check whether the layer has been loaded successfully.
+If it was not, an invalid layer instance is returned.
 
 For a geopackage vector layer:
 
 .. testcode:: loadlayer
 
- # get the path to a geopackage  e.g. /usr/share/qgis/resources/data/world_map.gpkg
- path_to_gpkg = os.path.join(QgsApplication.pkgDataPath(), "resources", "data", "world_map.gpkg")
+ # get the path to a geopackage
+ path_to_gpkg = "testdata/data/data.gpkg"
  # append the layername part
- gpkg_countries_layer = path_to_gpkg + "|layername=countries"
- # e.g. gpkg_places_layer = "/usr/share/qgis/resources/data/world_map.gpkg|layername=countries"
- vlayer = QgsVectorLayer(gpkg_countries_layer, "Countries layer", "ogr")
+ gpkg_airports_layer = path_to_gpkg + "|layername=airports"
+ vlayer = QgsVectorLayer(gpkg_airports_layer, "Airports layer", "ogr")
  if not vlayer.isValid():
      print("Layer failed to load!")
  else:
      QgsProject.instance().addMapLayer(vlayer)
 
 The quickest way to open and display a vector layer in QGIS is the
 :meth:`addVectorLayer() <qgis.gui.QgisInterface.addVectorLayer>`
-method of the :class:`QgisInterface <qgis.gui.QgisInterface>`:
+method of the :class:`QgisInterface <qgis.gui.QgisInterface>` class:
 
 .. testcode:: loadlayer
 
-    vlayer = iface.addVectorLayer(path_to_airports_layer, "Airports layer", "ogr")
+    vlayer = iface.addVectorLayer(gpkg_airports_layer, "Airports layer", "ogr")
     if not vlayer:
       print("Layer failed to load!")
 
@@ -110,23 +88,36 @@ providers:
 .. index::
    pair: Loading; GDAL layers
 
-* GDAL library (Shapefile and many other file formats) --- data source is the
-  path to the file:
+* The ogr provider from the GDAL library supports a `wide variety of formats
+  <https://gdal.org/en/latest/drivers/vector/index.html>`_,
+  also called drivers in GDAL speak. 
+  Examples are ESRI Shapefile, Geopackage, Flatgeobuf, Geojson, ...
+  For single-file formats the filepath usually suffices as uri.
+  For geopackages or dxf, a pipe separated suffix allows to specify the layer to load.
+
+  * for ESRI Shapefile:
+
+    .. code::
+
+      uri = "testdata/airports.shp"
+      vlayer = QgsVectorLayer(uri, "layer_name_you_like", "ogr")
+      QgsProject.instance().addMapLayer(vlayer)
 
-  * for Shapefile:
+  * for Geopackage (note the internal options in data source uri):
 
     .. testcode:: loadlayer
 
-       vlayer = QgsVectorLayer("testdata/airports.shp", "layer_name_you_like", "ogr")
-       QgsProject.instance().addMapLayer(vlayer)
+      uri = "testdata/data/data.gpkg|layername=airports"
+      vlayer = QgsVectorLayer(uri, "layer_name_you_like", "ogr")
+      QgsProject.instance().addMapLayer(vlayer)
 
   * for dxf (note the internal options in data source uri):
 
     .. testcode:: loadlayer
 
-       uri = "testdata/sample.dxf|layername=entities|geometrytype=Polygon"
-       vlayer = QgsVectorLayer(uri, "layer_name_you_like", "ogr")
-       QgsProject.instance().addMapLayer(vlayer)
+      uri = "testdata/sample.dxf|layername=entities|geometrytype=Polygon"
+      vlayer = QgsVectorLayer(uri, "layer_name_you_like", "ogr")
+      QgsProject.instance().addMapLayer(vlayer)
 
 .. index::
    pair: Loading; PostGIS layers
@@ -230,11 +221,6 @@ providers:
       uri = "https://demo.mapserver.org/cgi-bin/wfs?service=WFS&version=2.0.0&request=GetFeature&typename=ms:cities"
       vlayer = QgsVectorLayer(uri, "my wfs layer", "WFS")
 
-  .. .. testoutput:: loadlayer
-     :hide:
-
-     (2): Using non-preferred coordinate operation between EPSG:2964 and EPSG:4326. Using +proj=pipeline +step +proj=unitconvert +xy_in=us-ft +xy_out=m +step +inv +proj=aea +lat_0=50 +lon_0=-154 +lat_1=55 +lat_2=65 +x_0=0 +y_0=0 +ellps=clrk66 +step +proj=push +v_3 +step +proj=cart +ellps=clrk66 +step +proj=helmert +x=-5 +y=135 +z=172 +step +inv +proj=cart +ellps=WGS84 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg, preferred +proj=pipeline +step +proj=unitconvert +xy_in=us-ft +xy_out=m +step +inv +proj=aea +lat_0=50 +lon_0=-154 +lat_1=55 +lat_2=65 +x_0=0 +y_0=0 +ellps=clrk66 +step +proj=hgridshift +grids=us_noaa_alaska.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg.
-
   The uri can be created using the standard ``urllib`` library:
 
   .. testcode:: loadlayer

docs/pyqgis_developer_cookbook/vector.rst

@@ -73,18 +73,25 @@ by calling :meth:`fields() <qgis.core.QgsVectorLayer.fields>` on a
 
 .. testcode:: vectors
 
-    vlayer = QgsVectorLayer("testdata/airports.shp", "airports", "ogr")
+    vlayer = QgsVectorLayer("testdata/data/data.gpkg|layername=airports", "Airports layer", "ogr")
     for field in vlayer.fields():
         print(field.name(), field.typeName())
 
 
 .. testoutput:: vectors
 
-    ID Integer64
-    fk_region Integer64
-    ELEV Real
-    NAME String
-    USE String
+    fid Integer64
+    id Integer64
+    scalerank Integer64
+    featurecla String
+    type String
+    name String
+    abbrev String
+    location String
+    gps_code String
+    iata_code String
+    wikipedia String
+    natlscale Real
 
 The :meth:`displayField() <qgis.core.QgsVectorLayer.displayField>` and
 :meth:`mapTipTemplate() <qgis.core.QgsMapLayer.mapTipTemplate>` methods provide
@@ -96,13 +103,13 @@ methods you can easily get both:
 
 .. testcode:: vectors
 
-    vlayer = QgsVectorLayer("testdata/airports.shp", "airports", "ogr")
+    vlayer = QgsVectorLayer("testdata/data/data.gpkg|layername=airports", "Airports layer", "ogr")
     print(vlayer.displayField())
 
 
 .. testoutput:: vectors
 
-    NAME
+    name
 
 .. note:: If you change the ``Display Name`` from a field to an expression, you have to
    use :meth:`displayExpression() <qgis.core.QgsVectorLayer.displayExpression>`
@@ -703,7 +710,7 @@ field:
 
 .. testcode:: vectors
 
-    vlayer = QgsVectorLayer("testdata/airports.shp", "airports", "ogr")
+    vlayer = QgsVectorLayer("testdata/data/data.gpkg|layername=airports", "Airports layer", "ogr")
     feat = QgsVectorLayerUtils.createFeature(vlayer)
 
 
@@ -712,15 +719,15 @@ you to quickly get the values of a field or expression:
 
 .. testcode:: vectors
 
-    vlayer = QgsVectorLayer("testdata/airports.shp", "airports", "ogr")
+    vlayer = QgsVectorLayer("testdata/data/data.gpkg|layername=airports", "Airports layer", "ogr")
     # select only the first feature to make the output shorter
     vlayer.selectByIds([1])
     val = QgsVectorLayerUtils.getValues(vlayer, "NAME", selectedOnly=True)
     print(val)
 
 .. testoutput:: vectors
 
-    (['AMBLER'], True)
+    (['Sahnewal'], True)
 
 
 .. index:: Vector layers; Creating
@@ -1230,8 +1237,8 @@ arrangement)
 
   from qgis.PyQt import QtGui
 
-  myVectorLayer = QgsVectorLayer("testdata/airports.shp", "airports", "ogr")
-  myTargetField = 'ELEV'
+  myVectorLayer = QgsVectorLayer("testdata/data/data.gpkg|layername=airports", "Airports layer", "ogr")
+  myTargetField = 'scalerank'
   myRangeList = []
   myOpacity = 1
   # Make our first symbol and range...