Error in Processing modeller

[qgib]

Author Name: Paolo Cavallini (@pcav)
Original Redmine Issue: 20609
Affected QGIS version: 3.4.1
Redmine category:processing/modeller

---

when creating a model in Processing (QGIS 3.4.1), if one param is missing (band number in gdal contour), an error is thrown [0] before showing the proper error message.

[0]

An error has occurred while executing Python code: 

processing.gui.wrappers.InvalidParameterValue 

Traceback (most recent call last):
  File "/usr/local/src/qgis/QGIS/build-qgis341/output/python/plugins/processing/gui/wrappers.py", line 208, in widgetValue
    return self.value()
  File "/usr/local/src/qgis/QGIS/build-qgis341/output/python/plugins/processing/gui/wrappers.py", line 1764, in value
    return self.comboValue(validator)
  File "/usr/local/src/qgis/QGIS/build-qgis341/output/python/plugins/processing/gui/wrappers.py", line 174, in comboValue
    raise InvalidParameterValue()
processing.gui.wrappers.InvalidParameterValue


Python version: 3.6.7 (default, Oct 21 2018, 08:08:16) [GCC 8.2.0] 
QGIS version: 3.4.1-Madeira Madeira, f7bba750bc 

Python Path:

    /usr/local/src/qgis/QGIS/build-qgis341/output/python
    /home/paolo/.local/share/QGIS/QGIS3/profiles/Ghent course/python
    /home/paolo/.local/share/QGIS/QGIS3/profiles/Ghent course/python/plugins
    /usr/local/src/qgis/QGIS/build-qgis341/output/python/plugins
    /usr/lib/python36.zip
    /usr/lib/python3.6
    /usr/lib/python3.6/lib-dynload
    /usr/local/lib/python3.6/dist-packages
    /usr/lib/python3/dist-packages
    /home/paolo/.local/share/QGIS/QGIS3/profiles/Ghent course/python
    /home/paolo/Desktop/processing/modeler_twi

[qgib]

Author Name: Giovanni Manghi (@gioman)

---

• regression was changed from 0 to 1
• priority_id was changed from Normal to High
• category_id was changed from Processing/GDAL to Processing/Modeller

[qgib]

Author Name: Victor Olaya (@volaya)

---

Cannot reproduce.

I create a model and add a raster layer. When later I add the contour algorithm, the band parameter is populated with "1". I delete that value, leaving the box empty, and try to add the algorithm, but it correctly shows the warning message

Checking the code, the exception that you report is being correctly catched. The corresponding code is there since 2017...

Can you provide a more detailed explanation on how to reproduce the error?

---

• status_id was changed from Open to Feedback

[qgib]

Author Name: Paolo Cavallini (@pcav)

---

I can confirm, now the correct error is displayed.

---

• resolution was changed from to fixed/implemented
• status_id was changed from Feedback to Closed