Error al cargar una función definida por el usuario en QGIS

Question

¿Por qué se produce un error al cargar una función definida por el usuario en QGIS 3.12.2?

La expresión:

@qgsfunction(args='auto', group='Custom'):
def getHeight(layId, itemId, feature, parent):
    layout = QgsProject.instance().layoutManager().layoutByName(layId)
    item = layout.itemById(itemId)
    #item.refreshItemSize()
    return item.rect().height()

El mensaje de error:

2020-05-16T21:01:46 WARNING   getLayoutByName  
Traceback (most recent call last):
File "C:/PROGRA1/QGIS31.12/apps/qgis/./python\qgis\user.py", line 46, in load_user_expressions
import("expressions.{0}".format(name), locals(), globals())
File "C:/PROGRA1/QGIS31.12/apps/qgis/./python\qgis\utils.py", line 744, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
File "C:/Users/genf/AppData/Roaming/QGIS/QGIS3\profiles\default/python\expressions\getLayoutByName.py", line 1, in
@qgsfunction(args='auto', group='Custom')
NameError: name 'qgsfunction' is not defined

2020-05-16T21:01:46 WARNING   getTop  
Traceback (most recent call last):
File "C:/PROGRA1/QGIS31.12/apps/qgis/./python\qgis\user.py", line 46, in load_user_expressions
import("expressions.{0}".format(name), locals(), globals())
File "C:/PROGRA1/QGIS31.12/apps/qgis/./python\qgis\utils.py", line 744, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
File "C:/Users/genf/AppData/Roaming/QGIS/QGIS3\profiles\default/python\expressions\getTop.py", line 1, in
@qgsfunction(args='auto', group='Custom')
NameError: name 'qgsfunction' is not defined

Answer 1

NameError: name 'qgsfunction' is not defined

Es probable que sea porque no ha importado qgsfunction . Inténtalo:

from qgis.utils import qgsfunction

@qgsfunction(args='auto', group='Custom'):
def getHeight(layId, itemId, feature, parent):
    layout = QgsProject.instance().layoutManager().layoutByName(layId)
    item = layout.itemById(itemId)
    #item.refreshItemSize()
    return item.rect().height()