Automating QGIS project composer printing?

Question

I have a large project which consists of around 10x QGIS project files. Each project contains a print composer with an atlas set up to generate up to 10 maps.

What is the easiest way to automate the opening of each project and creating a PDF using the composer atlas?

(Something like this would be ideal - not sure if it's possible)

C:\OSGeo4W\bin\qgis.bat --project MyProject1.qgs --code SaveAtlasAsPdf.py C:\OSGeo4W\bin\qgis.bat --project MyProject2.qgs --code SaveAtlasAsPdf.py

Answer 1

Saving this in a Python file and using it in the --code arg should do what you need:

from PyQt4.QtCore import *
from PyQt4.QtGui import *
import os

from qgis.core import *
from qgis.gui import *
from qgis.utils import iface

for comp in iface.activeComposers():
    print comp
    folder = r"C:\temp"
    title = "testing"
    printer = QPrinter()
    painter = QPainter()
    comp.composition().setUseAdvancedEffects(False)
    myAtlas = comp.composition().atlasComposition()

    if myAtlas.enabled():
        myAtlas.beginRender()
        comp.composition().setAtlasMode(QgsComposition.ExportAtlas)
        myAtlas.setFilenamePattern(u"'{}_'||$feature".format(title))
        for i in range(0, myAtlas.numFeatures()):
            myAtlas.prepareForFeature(i)
            filename = os.path.join(folder, title + '.pdf')
            print filename
            comp.composition().beginPrintAsPDF(printer, filename)
            comp.composition().beginPrint(printer)
            printReady = painter.begin(printer)
            if i > 0:
                printer.newPage()
            comp.composition().doPrint(printer, painter)
        myAtlas.endRender()
        painter.end()

This will loop all composers and print them if they have atlas enabled into a single PDF for each one.

NOTE You can open a project file in a QGIS session using iface.addProject. So you could do this to avoid opening many QGIS sessions.

from PyQt4.QtCore import *
from PyQt4.QtGui import *
import os

from qgis.core import *
from qgis.gui import *
from qgis.utils import iface

def print_it():
    for comp in iface.activeComposers():
        print comp
        folder = r"C:\temp"
        title = "testing"
        printer = QPrinter()
        painter = QPainter()
        comp.composition().setUseAdvancedEffects(False)
        myAtlas = comp.composition().atlasComposition()

        if myAtlas.enabled():
            myAtlas.beginRender()
            comp.composition().setAtlasMode(QgsComposition.ExportAtlas)
            myAtlas.setFilenamePattern(u"'{}_'||$feature".format(title))
            for i in range(0, myAtlas.numFeatures()):
                myAtlas.prepareForFeature(i)
                filename = os.path.join(folder, title + '.pdf')
                print filename
                comp.composition().beginPrintAsPDF(printer, filename)
                comp.composition().beginPrint(printer)
                printReady = painter.begin(printer)
                if i > 0:
                    printer.newPage()
                comp.composition().doPrint(printer, painter)
            myAtlas.endRender()
            painter.end()

for project in projectlist:
    iface.addProject(project)
    print_it()