Showing QgsComposition created in QGIS Python console

Question

I'm trying to develop a similar script to How to make serial maps from template?. I'd like to modify elements in the composition programmatically for each map that I want to print. In developing this I'd like to see the elements I'm modifying in the console without printing off the map. I was expecting to see a new print composer window open when I ran the below code from the QGIS console in 2.18.2, but nothing happens (no error message appears either).

from qgis.PyQt.QtXml import QDomDocument
def loadPrintComposerTemplate(template):
    '''Load a print composer template from provided filename argument
Args:
    template: readable .qpt template filename

Returns:
    myComposition: a QgsComposition loaded from the provided template
    mapSettings: a QgsMapSettings object associated with myComposition'''
mapSettings = QgsMapSettings()
myComposition = QgsComposition(mapSettings)
# Load template from filename
with open(template, 'r') as templateFile:
    myTemplateContent = templateFile.read()

myDocument = QDomDocument()
myDocument.setContent(myTemplateContent)
return myComposition.loadFromTemplate(myDocument), mapSettings

composer, mapSet = loadPrintComposerTemplate(template)

Is there a way to make the print composer appear?

score 4 · Answer 1 · answered Jun 28 '17 at 16:57

4

The API has changed for QGIS3 :

from qgis.core import QgsComposition, QgsProject
composition = QgsComposition(QgsProject.instance())
composition.loadFromTemplate(template_qdoc)

answered Jun 28 '17 at 16:57

marcu

111
6

1

QgsComposition is not available anymore in recent qgis releases – luca76 Jul 20 '20 at 12:22
do you know to which class it was changed, @luca76? – MoritzMoreira Jul 24 '23 at 08:39

score 3 · Accepted Answer · edited Apr 13 '17 at 12:34

3

To open the new composer

from qgis.utils import iface
newcomp = iface.createNewComposer()

Load the template into the composer

newcomp.composition().loadFromTemplate(myDocument)

Has been taken from Here. Works in 2.18.2

edited Apr 13 '17 at 12:34

Community

1

answered Dec 29 '16 at 11:08

S. Thiyaku

855
6
17

Based on a reading of the documents one might think that loading the template into a QgsComposition and then using newcomp.setComposition(myComposition) would produce the same results. But I'm noting missing elements on the composer page, and the Items list is empty in the composer window – raphael Dec 30 '16 at 18:25
Also note that newcomp.composerWindow() has a hide() and show() method – raphael Jan 16 '17 at 16:51

Showing QgsComposition created in QGIS Python console

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