PyQGIS cookbook updates during the Coruna Dev meeting

* cookbook data structure

* pyqgis cookbook project + data

* add 2 raster dataset to the gpkg

* pyqgis raster chapter tested and ready to use

* load vector layer improvements

* show how to load a gpkg layer

* be more specific about code imports

* add specific imports at the beggining

* finish loading vector layers

* better raster layer loading

* finished loadlayer pycook

* verify composer rst completed

* finish verifying communication with the user pyqgis chapter

* show how to load raster from gpkg

* [settings.rst] Doublecheck code, add imports and comments, fix typos (qgis#3514)

* [settings.rst] Doublecheck code, add imports and comments, fix typos

* [settings.rst] Move all import to top

* [settings.rst] fix whitespace issue

* fix mapcanvas imports

* some small fixes + reorder for consistency

* fix rubberband + vertex markers

* [geometry.rst] tested and updated geometry.rst of the pyqgis cookbook (qgis#3522)

* Changed code snippets to be self-contained examples, minor edits to tutorial text

* Update geometry.rst

minor text formatting

* Update source/docs/pyqgis_developer_cookbook/geometry.rst

Co-Authored-By: arongergely <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/geometry.rst

Co-Authored-By: arongergely <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/geometry.rst

Co-Authored-By: arongergely <[email protected]>

* Split line in code snippet for legibility

* Added a snippet with all the imports

* Minor snippet and non-code text edits

* .rst markup fix

* Removed prompt strings ('>>>') from snippets, small corrections to code examples

* Improve characthers max number

* Update source/docs/pyqgis_developer_cookbook/loadlayer.rst

Co-Authored-By: SrNetoChan <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/communicating.rst

Co-Authored-By: SrNetoChan <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/communicating.rst

Co-Authored-By: SrNetoChan <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/geometry.rst

Co-Authored-By: SrNetoChan <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/geometry.rst

Co-Authored-By: SrNetoChan <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/geometry.rst

Co-Authored-By: SrNetoChan <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/geometry.rst

Co-Authored-By: SrNetoChan <[email protected]>

* Update source/docs/pyqgis_developer_cookbook/loadlayer.rst

Co-Authored-By: SrNetoChan <[email protected]>

Author: SrNetoChan

qgis-projects/python_cookbook/01_project.qgs

@@ -90,22 +90,101 @@ layers for canvas
 
 .. code-block:: python
 
-  layer = QgsVectorLayer(path, name, provider)
-  if not layer.isValid():
-    raise IOError, "Failed to open the layer"
+ path_to_ports_layer = os.path.join(QgsProject.instance().homePath(), "data", "ports", "ports.shp")
 
-  # add layer to the registry
-  QgsProject.instance().addMapLayer(layer)
+ vlayer = QgsVectorLayer(path_to_ports_layer, "Ports layer", "ogr")
+ if not vlayer.isValid():
+     print("Layer failed to load!")
 
-  # set extent to the extent of our layer
-  canvas.setExtent(layer.extent())
+ # add layer to the registry
+ QgsProject.instance().addMapLayer(vlayer)
 
-  # set the map canvas layer set
-  canvas.setLayers([layer])
+ # set extent to the extent of our layer
+ canvas.setExtent(vlayer.extent())
+
+ # set the map canvas layer set
+ canvas.setLayers([vlayer])
 
 After executing these commands, the canvas should show the layer you have
 loaded.
 
+.. index:: Map canvas; Rubber bands, Map canvas; Vertex markers
+
+Rubber Bands and Vertex Markers
+===============================
+
+To show some additional data on top of the map in canvas, use map canvas items.
+It is possible to create custom canvas item classes (covered below), however
+there are two useful canvas item classes for convenience:
+:class:`QgsRubberBand <qgis.gui.QgsRubberBand>` for drawing polylines or polygons, and
+:class:`QgsVertexMarker <qgis.gui.QgsVertexMarker>` for drawing points. They both work with map
+coordinates, so the shape is moved/scaled automatically when the canvas is
+being panned or zoomed.
+
+To show a polyline
+
+.. code-block:: python
+
+  r = QgsRubberBand(canvas, False)  # False = not a polygon
+  points = [QgsPoint(-100, 45), QgsPoint(10, 60), QgsPoint(120, 45)]
+  r.setToGeometry(QgsGeometry.fromPolyline(points), None)
+
+To show a polygon
+
+.. code-block:: python
+
+  r = QgsRubberBand(canvas, True)  # True = a polygon
+  points = [[QgsPointXY(-100, 35), QgsPointXY(10, 50), QgsPointXY(120, 35)]]
+  r.setToGeometry(QgsGeometry.fromPolygonXY(points), None)
+
+Note that points for polygon is not a plain list: in fact, it is a list of
+rings containing linear rings of the polygon: first ring is the outer border,
+further (optional) rings correspond to holes in the polygon.
+
+Rubber bands allow some customization, namely to change their color and line
+width
+
+.. code-block:: python
+
+  r.setColor(QColor(0, 0, 255))
+  r.setWidth(3)
+
+The canvas items are bound to the canvas scene. To temporarily hide them (and
+show them again), use the :func:`hide` and :func:`show` combo. To completely remove
+the item, you have to remove it from the scene of the canvas
+
+.. code-block:: python
+
+  canvas.scene().removeItem(r)
+
+(in C++ it's possible to just delete the item, however in Python ``del r``
+would just delete the reference and the object will still exist as it is owned
+by the canvas)
+
+Rubber band can be also used for drawing points, but the
+:class:`QgsVertexMarker <qgis.gui.QgsVertexMarker>` class is better suited for this
+(:class:`QgsRubberBand <qgis.gui.QgsRubberBand>` would only draw a rectangle around the desired point).
+
+You can use the vertex marker like this:
+
+.. code-block:: python
+
+  m = QgsVertexMarker(canvas)
+  m.setCenter(QgsPointXY(10,40))
+
+This will draw a red cross on position **[10,45]**. It is possible to customize the
+icon type, size, color and pen width
+
+.. code-block:: python
+
+  m.setColor(QColor(0, 255, 0))
+  m.setIconSize(5)
+  m.setIconType(QgsVertexMarker.ICON_BOX) # or ICON_CROSS, ICON_X
+  m.setPenWidth(3)
+
+For temporary hiding of vertex markers and removing them from canvas, use the same methods
+as for rubber bands.
+
 .. index:: Map canvas; Map tools
 
 Using Map Tools with Canvas
@@ -123,9 +202,8 @@ are activated using :meth:`setMapTool() <qgis.gui.QgsMapCanvas.setMapTool>` meth
 .. code-block:: python
 
   from qgis.gui import *
-  from qgis.PyQt.QtGui import QAction
+  from PyQt5.QtWidgets import QAction, QMainWindow
   from qgis.PyQt.QtCore import Qt
-  from qgis.PyQt.QtWidgets import QMainWindow
 
   class MyWnd(QMainWindow):
       def __init__(self, layer):
@@ -182,86 +260,8 @@ selected layer on the newly created canvas
 
 .. code-block:: python
 
-  import mywnd
-  w = mywnd.MyWnd(iface.activeLayer())
-  w.show()
-
-.. index:: Map canvas; Rubber bands, Map canvas; Vertex markers
-
-Rubber Bands and Vertex Markers
-===============================
-
-To show some additional data on top of the map in canvas, use map canvas items.
-It is possible to create custom canvas item classes (covered below), however
-there are two useful canvas item classes for convenience:
-:class:`QgsRubberBand <qgis.gui.QgsRubberBand>` for drawing polylines or polygons, and
-:class:`QgsVertexMarker <qgis.gui.QgsVertexMarker>` for drawing points. They both work with map
-coordinates, so the shape is moved/scaled automatically when the canvas is
-being panned or zoomed.
-
-To show a polyline
-
-.. code-block:: python
-
-  r = QgsRubberBand(canvas, False)  # False = not a polygon
-  points = [QgsPoint(-1, -1), QgsPoint(0, 1), QgsPoint(1, -1)]
-  r.setToGeometry(QgsGeometry.fromPolyline(points), None)
-
-To show a polygon
-
-.. code-block:: python
-
-  r = QgsRubberBand(canvas, True)  # True = a polygon
-  points = [[QgsPoint(-1, -1), QgsPoint(0, 1), QgsPoint(1, -1)]]
-  r.setToGeometry(QgsGeometry.fromPolygon(points), None)
-
-Note that points for polygon is not a plain list: in fact, it is a list of
-rings containing linear rings of the polygon: first ring is the outer border,
-further (optional) rings correspond to holes in the polygon.
-
-Rubber bands allow some customization, namely to change their color and line
-width
-
-.. code-block:: python
-
-  r.setColor(QColor(0, 0, 255))
-  r.setWidth(3)
-
-The canvas items are bound to the canvas scene. To temporarily hide them (and
-show them again), use the :func:`hide` and :func:`show` combo. To completely remove
-the item, you have to remove it from the scene of the canvas
-
-.. code-block:: python
-
-  canvas.scene().removeItem(r)
-
-(in C++ it's possible to just delete the item, however in Python ``del r``
-would just delete the reference and the object will still exist as it is owned
-by the canvas)
-
-Rubber band can be also used for drawing points, but the
-:class:`QgsVertexMarker <qgis.gui.QgsVertexMarker>` class is better suited for this
-(:class:`QgsRubberBand <qgis.gui.QgsRubberBand>` would only draw a rectangle around the desired point).
-
-You can use the vertex marker like this:
-
-.. code-block:: python
-
-  m = QgsVertexMarker(canvas)
-  m.setCenter(QgsPointXY(0, 0))
-
-This will draw a red cross on position [0,0]. It is possible to customize the
-icon type, size, color and pen width
-
-.. code-block:: python
-
-  m.setColor(QColor(0, 255, 0))
-  m.setIconSize(5)
-  m.setIconType(QgsVertexMarker.ICON_BOX) # or ICON_CROSS, ICON_X
-  m.setPenWidth(3)
-
-For temporary hiding of vertex markers and removing them from canvas, use the same methods
-as for rubber bands.
+ w = MyWnd(iface.activeLayer())
+ w.show()
 
 .. index:: Map canvas; Custom map tools
 

qgis-projects/python_cookbook/data/data.gpkg

@@ -140,17 +140,25 @@ it accepts widgets. Here is an example that you can try in the console.
     iface.messageBar().clearWidgets()
 
 Also, you can use the built-in status bar to report progress, as in the next
-example
+example:
 
 .. code-block:: python
 
-    count = layer.featureCount()
-    for i, feature in enumerate(features):
-        #do something time-consuming here
-        ...
-        percent = i / float(count) * 100
-        iface.mainWindow().statusBar().showMessage("Processed {} %".format(int(percent)))
-    iface.mainWindow().statusBar().clearMessage()
+ vlayer = QgsProject.instance().mapLayersByName("countries")[0]
+
+ count = vlayer.featureCount()
+ features = vlayer.getFeatures()
+
+ for i, feature in enumerate(features):
+     # do something time-consuming here
+     print('') # printing should give enough time to present the progress
+
+     percent = i / float(count) * 100
+     # iface.mainWindow().statusBar().showMessage("Processed {} %".format(int(percent)))
+     iface.statusBarIface().showMessage("Processed {} %".format(int(percent)))
+
+ iface.statusBarIface().clearMessage()
+
 
 Logging
 =======
@@ -173,11 +181,19 @@ save about the execution of your code.
  cases you should always use thread safe classes (:class:`QgsLogger <qgis.core.QgsLogger>`
  or :class:`QgsMessageLog <qgis.core.QgsMessageLog>`) instead.
 
+
 .. note::
 
    You can see the output of the :class:`QgsMessageLog <qgis.core.QgsMessageLog>`
    in the :ref:`log_message_panel`
 
+.. note::
+
+ * :class:`QgsLogger <qgis.core.QgsLogger>` is for messages for debugging /
+   developers (i.e. you suspect they are triggered by some broken code)
+ * :class:`QgsMessageLog <qgis.core.QgsMessageLog>` is for messages to
+   investigate issues by sysadmins (e.g. to help a sysadmin to fix configurations)
+
 
 .. Substitutions definitions - AVOID EDITING PAST THIS LINE
    This will be automatically updated by the find_set_subst.py script.

qgis-projects/python_cookbook/data/srtm.tif

@@ -1,7 +1,3 @@
-.. only:: html
-
-   |updatedisclaimer|
-
 .. index:: Map rendering, Map printing
 
 .. _layout:
@@ -10,7 +6,11 @@
 Map Rendering and Printing
 **************************
 
-.. warning:: |outofdate|
+The code snippets on this page needs the following imports:
+
+.. code-block:: python
+
+ import os
 
 .. contents::
    :local:
@@ -28,27 +28,31 @@ The rendering is done creating a :class:`QgsMapSettings <qgis.core.QgsMapSetting
 and then constructing a :class:`QgsMapRendererJob <qgis.core.QgsMapRendererJob>` with those options. The latter is then
 used to create the resulting image.
 
-Here's an example
+Here's an example:
 
 .. code-block:: python
 
-  layer=iface.activeLayer()
-  options = QgsMapSettings()
-  options.setLayers([layer])
-  options.setBackgroundColor(QColor(255, 255, 255))
-  options.setOutputSize(QSize(800, 600))
-  options.setExtent(layer.extent())
+ image_location = os.path.join(QgsProject.instance().homePath(), "render.png")
+
+ # e.g. vlayer = iface.activeLayer()
+ vlayer = QgsProject.instance().mapLayersByName("countries")[0]
+ options = QgsMapSettings()
+ options.setLayers([vlayer])
+ options.setBackgroundColor(QColor(255, 255, 255))
+ options.setOutputSize(QSize(800, 600))
+ options.setExtent(vlayer.extent())
 
-  render = QgsMapRendererParallelJob(options)
+ render = QgsMapRendererParallelJob(options)
 
-  def finished():
-      img = render.renderedImage()
-      img.save("/Users/myuser/render.png","png")
-      print("saved")
+ def finished():
+     img = render.renderedImage()
+     # save the image; e.g. img.save("/Users/myuser/render.png","png")
+     img.save(image_location, "png")
+     print("saved")
 
-  render.finished.connect(finished)
+ render.finished.connect(finished)
 
-  render.start()
+ render.start()
 
 
 Rendering layers with different CRS
@@ -100,7 +104,7 @@ Here's a description of some of the main layout items that can be added to a lay
   .. code-block:: python
 
     map = QgsLayoutItemMap(layout)
-    layout.addItem(mapp)
+    layout.addItem(map)
 
 * label --- allows displaying labels. It is possible to modify its font, color,
   alignment and margin
@@ -170,7 +174,8 @@ A frame is drawn around each item by default. You can remove it as follows:
 
 .. code-block:: python
 
-  composerLabel.setFrameEnabled(False)
+  # for a composer label
+  label.setFrameEnabled(False)
 
 Besides creating the layout items by hand, QGIS has support for layout
 templates which are essentially compositions with all their items saved to a
@@ -188,8 +193,10 @@ To export a layout, the :class:`QgsLayoutExporter <qgis.core.QgsLayoutExporter>`
 
 .. code-block:: python
 
-  exporter = QgsLayoutExporter(layout)
-  exporter.exportToPdf("path/to/output/pdf", QgsLayoutExporter.PdfExportSettings())
+ pdf_path = os.path.join(QgsProject.instance().homePath(), "output.pdf")
+
+ exporter = QgsLayoutExporter(layout)
+ exporter.exportToPdf(pdf_path, QgsLayoutExporter.PdfExportSettings())
 
 Use the :meth:`exportToImage() <qgis.core.QgsLayoutExporter.exportToImage>` in case you want to export to an image instead of a PDF file.