Add layouts from templates using PyQGIS: the page orientation is not preserved

Question

For each new QGIS project, I want to add a few layouts from prepared templates.

All templates are vertically oriented (A4 portrait). Inspecting the templates (the XML contents), I can see a <LayoutItem> with a proper size="210,297,mm", as in this example:

<LayoutItem positionLock="false" zValue="0" frame="false" referencePoint="0" itemRotation="0" id="" size="210,297,mm" outlineWidthM="0.3,mm" positionOnPage="0,0,mm" position="0,0,mm" visibility="1" type="65638" frameJoinStyle="miter" opacity="1" background="true" blendMode="0" uuid="{3156912c-ce6e-4d02-8dfc-bc7c36b8f738}" templateUuid="{3156912c-ce6e-4d02-8dfc-bc7c36b8f738}" groupUuid="" excludeFromExports="0">

Adding templates manually

If I add the templates using the GUI, it works. The template is added and I get a new layout, with the correct page orientation, as expected.

Adding templates with PyQGIS

Since I want to add a few templates, I would like to add them using PyQGIS.

The minimal code is this:

project = QgsProject.instance()
layout = QgsPrintLayout(project)
layout.initializeDefaults()

with open('/home/jgr/Templates/reserva.qpt') as f:
    template_content = f.read()
    doc = QDomDocument()
    doc.setContent(template_content)
    items, ok = layout.loadFromTemplate(doc, QgsReadWriteContext(), False)
    layout.setName('reserva')
    project.layoutManager().addLayout(layout)

The layout is created without the proper orientation. The generated layout from the templates is horizontally oriented, but the template is vertically oriented.

What am I missing in this PyQGIS script?

Answer 1

layout.initializeDefaults() creates an almost empty layout. The generated layout has already one page, with the default orientation.

Setting clearExisting = True when calling layout.loadFromTemplate rewrites the default layout with the template's orientation. More info on the loadFromTemplate documentation.

The entire code should be:

project = QgsProject.instance()
layout = QgsPrintLayout(project)
layout.initializeDefaults()

with open('/home/jgr/Templates/reserva.qpt') as f:
    template_content = f.read()
    doc = QDomDocument()
    doc.setContent(template_content)
    items, ok = layout.loadFromTemplate(doc, QgsReadWriteContext(), True)
    layout.setName('reserva')
    project.layoutManager().addLayout(layout)