Batch "Save as" layers w.r.t their geometry type in QGIS?

Question

We have 100's of dgn files. We have successfully "assigned" coordinate system to those dgn files in batch by using "on the fly" + custom CRS. Now we have to save each dgn's geometry (Point, Linestring, Polygon) in WGS84. Manually we can do that. Right Click -> Save Us -> Projection: WGS84 & add suffix "Point, Lines, Areas" to each layer. But this method will take a lot of time to do that. What i would like to do is

1) Based on the File name, the layers has to be batch saved to a respective folder. I have read this and tried. How to batch "Layer save as"-process in QGIS? But it takes the layer name (here: elementsPoints, elementsLineString) instead of the original file name (042641hd). I would like to have 042641hd_Points, 042641hd_Lines etc..

2) While doing so, how to save all the files in WGS84 ?

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This code works perfectly. Reading the file name, not the layer name.

 from qgis.core import *
 import os
 pathToFile = "D:\\Dummy\\"
 trs = QgsCoordinateReferenceSystem()
 trs.createFromId(4326)
 layers = iface.legendInterface().layers()
 for layer in layers:
     dgn_pn = layer.dataProvider().dataSourceUri().split('|')[0]
     dgn_fn = os.path.basename(dgn_pn)
     dgn_fn_wo_ext = os.path.splitext(dgn_fn)[0]
     geom_name = {0: 'Points', 1: 'Lines', 2: 'Polygons'}
     geom_type = layer.geometryType()
     newName = dgn_fn_wo_ext + '_' + geom_name[geom_type]
     ret = QgsVectorFileWriter.writeAsVectorFormat(layer,pathToFile + newName,'utf-8',trs,'ESRI Shapefile')
     if ret == QgsVectorFileWriter.NoError:
       print newName + " saved to " + pathToFile + "!"   

Answer 1

You already know the general procedure and have experience with the script How to batch "Layer save as"-process in QGIS?. Consider the line

QgsVectorFileWriter.writeAsVectorFormat(layer, pathToFile + newName, "utf-8", None, "ESRI Shapefile")

You have to change 2 things.

1) To get the original file name add following lines to the top of the loop

import os

for layer in layers:
    # get path to dgn file
    dgn_pn = layer.dataProvider().dataSourceUri().split('|')[0]
    dgn_fn = os.path.basename(dgn_pn)

    # get rid of the file extension
    dgn_fn_wo_ext = os.path.splitext(dgn_fn)[0]

    # define geometry strings and get geometry type of layer
    geom_name = {0: 'Points', 1: 'Lines', 2: 'Polygons'}
    geom_type = layer.geometryType()

    # build the new file name
    newName = dgn_fn_wo_ext + '_' + geom_name[geom_type]

2) To change the coordinate system to WGS84 add to the top of the script

trs = QgsCoordinateReferenceSystem()
trs.createFromId(4326)

To bring it all together change following line:

ret = QgsVectorFileWriter.writeAsVectorFormat(
         layer, 
         pathToFile + newName, 
         'utf-8',
         trs,
         'ESRI Shapefile')

Answer 2

I have a QGIS project with a lot of KML files in WGS84 in them. I would like to batch save them all to the directories they come from in Lambert72 (EPSG: 31370) as a .shp file. I have cooked up my own little script from the above and some help form Detlev.

from qgis.core import *
import os
pathToFile = "S:\\Meetnetten\\Amfibieen en reptielen\\Vuursalamander\\Transecten 2016\\"
trs = QgsCoordinateReferenceSystem()
trs.createFromId(31370)
suffix = "_Lambert1972_Versie2016-01-04"
prefix = "Transect_Vuursalamander_"
layers = iface.legendInterface().layers()
for layer in layers:
    dgn_pn = layer.dataProvider().dataSourceUri().split('|')[0]
    dgn_fn = os.path.dirname(dgn_pn)
    newName = prefix + layer.name() + suffix + ".shp"
    ret = QgsVectorFileWriter.writeAsVectorFormat(layer, dgn_fn + \\ +  newName,'utf-8',trs,'ESRI Shapefile')
    if ret == QgsVectorFileWriter.NoError:
        print newName + " saved to " + dgn_fn + "!"