Atlas crash using python

[qgib]

Author Name: Loïc BARTOLETTI (@lbartoletti)
Original Redmine Issue: 17180
Affected QGIS version: 2.18.13
Redmine category:python_bindings_/_sipify

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Hi,

I asked a question on https://gis.stackexchange.com/questions/256143/duplicate-composition-with-python-qgis about a need to duplicate a composer and deal with it in python.

It's maybe a bad code from me, but since it crashes QGis (tested on Windows and FreeBSD), I open a ticket here to let you know.

Thanks.

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Related issue(s): #25080 (relates)
Redmine related issue(s): 17181

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[qgib]

Author Name: Giovanni Manghi (@gioman)

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This ticket (#25079) or this #25080 ?

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• status_id was changed from Open to Feedback

[qgib]

Author Name: Loïc BARTOLETTI (@lbartoletti)

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Both #25080 (comment)

[qgib]

Author Name: Giovanni Manghi (@gioman)

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Please add a description.

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• status_id was changed from Feedback to Open

[qgib]

Author Name: Loïc BARTOLETTI (@lbartoletti)

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For this issue, when you use an invalid output dir, you don't have a crash but it's return my print debug "exportAsPdf", so I suspect a problem into this method (can't see or produce logs now).

[qgib]

Author Name: Loïc BARTOLETTI (@lbartoletti)

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Since it's not available in Qgis 2, I'm trying to duplicate a composition with pyqgis translating "this code":

QGIS/src/core/composer/qgslayoutmanager.cpp

Line 157 in f0709ae

QgsComposition *QgsLayoutManager::duplicateComposition( const QString &name, const QString &newName )

from Qgis 3.
Duplication is fine, but every time I want to export an atlas of this new composition, qgis crash. Do you have any idea?

Here is a reproductible example of my code (using with python console and a small project):

    from qgis.PyQt.QtXml import *
    from qgis.PyQt.QtGui import *
    from qgis.PyQt.QtWidgets import *
    from qgis.PyQt.QtCore import *

    import os

    def saveAsTemplate(composition):
        doc = QDomDocument()
        composerElem = doc.createElement(  "Composer"  )
        doc.appendChild( composerElem )
        composition.writeXML( composerElem, doc )
        composition.atlasComposition().writeXML( composerElem, doc )
        return doc

    def duplicateComposition(composition):
        currentDoc = saveAsTemplate(composition)
        compositionElem = currentDoc.documentElement().firstChildElement( "Composition" )
        if compositionElem.isNull():
            print( "selected composer could not be stored as temporary template" )
            return None
            
        newComposition = QgsComposition(composition.mapSettings())
        
        if not newComposition.loadFromTemplate(currentDoc):
            print( " Cannot load template ")
            del newComposition
            return None
            
        return newComposition
        

    myComposition = iface.activeComposers()[0].composition()
    newComposition = duplicateComposition(myComposition)

    atlas = newComposition.atlasComposition()
    atlasLayer = iface.activeLayer()
    atlas.setCoverageLayer(atlasLayer)
    atlas.setPageNameExpression(atlasLayer.name())
    atlas.setEnabled( True )
    ret = newComposition.setAtlasMode( QgsComposition.ExportAtlas )
    if ret is False:
        print "Error"


    outputDir = "C:/temp/export_atlas"
    atlas.beginRender()
    print("atlas")
    num = atlas.numFeatures()
    for i in range(0, num):
        ret = atlas.prepareForFeature( i )
        if ret is False:
            print "prepareForFeatureror"
        printer = QPrinter()
        printer.setOutputFormat(QPrinter.PdfFormat)
        ret = newComposition.exportAsPDF(os.path.join(outputDir, str(i)+".pdf"))
        if ret is False:
            print "exportAsPDF"

    atlas.endRender()

"Original message":https://gis.stackexchange.com/questions/256143/duplicate-composition-with-python-qgis

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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• relates was configured as Crash using QgsComposerAttributeTableV2 after setting columns #25080

[qgib]

Author Name: Denis Rouzaud (@3nids)

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• assigned_to_id removed Denis Rouzaud

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• priority_id was changed from Normal to High

[qgib]

Author Name: Jürgen Fischer (@jef-n)

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Please test with QGIS 3.4 - QGIS 2.18 reached it's end of life.

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• status_id was changed from Open to Feedback

[qgib]

Author Name: Loïc BARTOLETTI (@lbartoletti)

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• status_id was changed from Feedback to Closed