Concave hull not working in Processing (QGIS3)

[qgib]

Author Name: matteo ghetta (@ghtmtt)
Original Redmine Issue: 15985
Affected QGIS version: master
Redmine category:processing/qgis
Assignee: Nyall Dawson

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Concave hull algorithm always throws an error. In QGIS 2.18 it works fine (tested with point data within the processing test framework)

2016-12-15T10:47:55 2 Uncaught error while executing algorithm
Traceback (most recent call last):
File "/home/matteo/lavori/QGIS/build-qgis3/output/python/plugins/processing/core/GeoAlgorithm.py", line 213, in execute
self.processAlgorithm(progress)
File "/home/matteo/lavori/QGIS/build-qgis3/output/python/plugins/processing/algs/qgis/ConcaveHull.py", line 76, in processAlgorithm
features = delaunay_layer.getFeatures()
AttributeError: 'NoneType' object has no attribute 'getFeatures'

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• priority_id was changed from Normal to Severe/Regression

[qgib]

Author Name: Alexander Bruy (@alexbruy)

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This happens because now temporary layers are memory layers and Processing fails to locate algorithm result

[qgib]

Author Name: matteo ghetta (@ghtmtt)

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Ok, any chance or way to fix this? Can I help making other tests?

Thanks again!

[qgib]

Author Name: Arnaud Morvan (@arnaud-morvan)

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For now, with Nyall work on porting processing to c++.
The @processing.run@ method create a @QgsProcessingContext@ (in @Processing.runAlgorithm@) and the ouput, some memory layer is placed in @context.temporaryStore@.
But it is not possible to pass the parent (caller) algorithm context to @processing.run@ so it is not possible to get back the layer object.

I see the possibility to add a context parameter to processing.run, like is done with feedback.

[qgib]

Author Name: Arnaud Morvan (@arnaud-morvan)

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Here is a pull request that highlight the situation : #4439
It fix the error, but Nyall may have other plans.

[qgib]

Author Name: Arnaud Morvan (@arnaud-morvan)

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• assigned_to_id was changed from Victor Olaya to Nyall Dawson

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• regression was configured as 1

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• priority_id was changed from Severe/Regression to High

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• easy_fix was configured as 0

[qgib]

Author Name: Arnaud Morvan (@arnaud-morvan)

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Applied in changeset e232a08.

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• done_ratio was changed from 0 to 100
• status_id was changed from Open to Closed