QGIS Python composer export problem when using a function [closed]

Question

I try to write a python script in order to do the following:

1. load a vector layer
2. open an existing composition
3. export the composition as PDF

If I use this simplified code in the Python console of QGis. Everything is working fine, the new layer is added and exported with the composition (you must have at least one composer in your project) :

from PyQt4.QtGui import *
vectorLyr = QgsVectorLayer("d:/test.shp", 'test','ogr')
if not vectorLyr.isValid():
    print "Layer %s did not load" % vectorLyr.name()

vectorLyr.updateExtents()
iface.mapCanvas().refresh()
reg = QgsMapLayerRegistry.instance()
reg.addMapLayer(vectorLyr)
#load first composition
comp = iface.activeComposers()[0].composition()
comp.refreshItems()
comp.setUseAdvancedEffects(True)
comp.exportAsPDF('d:/tmp/test.pdf')
# export is correct

but once I try to generalize the code by creating an export function, the layer is no longer exported with the composition:

from PyQt4.QtGui import *

def export(layerPath, layerName):
    vectorLyr = QgsVectorLayer(layerPath, layerName,"ogr")
    if not vectorLyr.isValid():
        print "Layer %s did not load" % vectorLyr.name()

    vectorLyr.updateExtents()
    iface.mapCanvas().refresh()
    reg = QgsMapLayerRegistry.instance()
    reg.addMapLayer(vectorLyr)
    comp = iface.activeComposers()[0].composition()
    comp.refreshItems()
    comp.setUseAdvancedEffects(True)
    comp.exportAsPDF('d:/tmp/test.pdf')
    return

export("d:/test.shp", "test")
#the vector layer added dynamically is not on the map

I'm new to Python and new to QGis API. Any idea of what I'm missing?

Answer 1

I am unable to figure out what is exact reason problem ? I am getting error "Layer test did not load". The solution is try passing only location as first parameter and layer name as second parameter. export("d:/", "test"). If I change that works good for me