Provide an error message if there is a CRS mismatch. Fixes #5

borysiasty · Jan 9, 2018 · cbdf545 · cbdf545
1 parent fbce01b
commit cbdf545
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diff --git a/CHANGELOG b/CHANGELOG
@@ -1,3 +1,7 @@
+ver 0.4.2
+Provide an error message if there is a CRS mismatch. Fixes #5
+
+
 ver 0.4.1
 Multiselection of columns and bands with Ctrl and Shift keys
 
@@ -9,6 +13,7 @@ First Version for QGIS 2
 ver 0.3.8  (The last version for QGIS 1.x)
 Fix bug introduced in 0.3.7
 
+
 ver 0.3.7
 Optimizations for VRT rasters.
 Recent (0.3.6) polygon optimizations ported also to API <=1.8

diff --git a/doPointSamplingTool.py b/doPointSamplingTool.py
@@ -225,21 +225,49 @@ def accept(self): # Called when "OK" button pressed (based on the Carson Farmer'
    for j in range(1, len(self.rastItems[i])):
     if self.rastItems[i][j][2]:
      nothingSelected = False
+
   if self.inSample.currentText() == "":
    self.tabWidget.setCurrentIndex(0)
    QMessageBox.information(self, "Point Sampling Tool", "Please select vector layer containing the sampling points")
-  elif nothingSelected:
+   return
+  if nothingSelected:
    self.tabWidget.setCurrentIndex(0)
-   QMessageBox.information(self, "Point Sampling Tool", "Please select at least one polygon or raster layer")
-  elif self.outShape.text() == "":
+   QMessageBox.information(self, "Point Sampling Tool", "Please select at least one polygon attribute or raster band")
+   return
+  if self.outShape.text() == "":
    self.tabWidget.setCurrentIndex(0)
    QMessageBox.information(self, "Point Sampling Tool", "Please specify output shapefile name")
+   return
   # check if destination field names are unique
-  elif not self.testFieldsNames(self.fields):
+  if not self.testFieldsNames(self.fields):
    self.updateFieldsTable()
    self.tabWidget.setCurrentIndex(1)
    QMessageBox.warning(self, "Point Sampling Tool", "At least two field names are the same!\nPlease type unique names.")
-  else:
+   return
+
+  # Check if there a CRS mismatch
+  pointLayerSrid = self.sampItems.values()[0][0].crs().postgisSrid()
+  msg = u'''<html>All layers must have the same coordinate refere system. The <b>%s</b> layer seems to have different CRS id (<b>%d</b>)
+            than the point layer (<b>%d</b>). If they are two different CRSes, you need to reproject one of the layers first,
+            otherwise results will be wrong.<br/>
+            However, if you are sure both CRSes are the same, and they are just improperly recognized, you can safely continue.
+            Do you want to continue?</html>'''
+  for i in self.polyItems:
+   for j in range(1, len(self.polyItems[i])):
+    if self.polyItems[i][j][2]:
+     layerSrid = self.polyItems[i][0].crs().postgisSrid()
+     if layerSrid != pointLayerSrid:
+      if QMessageBox.question(self, "Point Sampling Tool: layer CRS mismatch!", msg % (i, layerSrid, pointLayerSrid), QMessageBox.Yes | QMessageBox.No) != QMessageBox.Yes:
+       return
+  for i in self.rastItems:
+   for j in range(1, len(self.rastItems[i])):
+    if self.rastItems[i][j][2]:
+     layerSrid = self.rastItems[i][0].crs().postgisSrid()
+     if layerSrid != pointLayerSrid:
+      if QMessageBox.question(self, "Point Sampling Tool: layer CRS mismatch!", msg % (i, layerSrid, pointLayerSrid), QMessageBox.Yes | QMessageBox.No) != QMessageBox.Yes:
+       return
+
+  if True:
    # all tests passed! Let's go on
    self.statusLabel.setText("Processing the output file name...")
    self.repaint()

diff --git a/metadata.txt b/metadata.txt
@@ -13,7 +13,7 @@ name=Point sampling tool
 description=Samples polygon attributes and raster values from multiple layers at specified sampling points
 description[pl]=Próbkuje atrybuty poligonów i/lub wartości rastra (również z wielu warstw naraz) w podanych punktach.
 about=The Point Sampling Tool Plugin collects polygon attributes and raster values from multiple layers at specified sampling points. You need a point layer with locations of sampling points and at least one polygon or raster layer to probe values from. The plugin creates a new point layer with locations given by the sampling points and attributes taken from all the underlying polygons or/and raster cells. Please use Control and Shift keys in order to select multiple columns and bands. Note this tool is not compatible with mulitipoint sources, unless each multipoint contains exactly one point. Using multipoint samples that contain more points in multipoints may produce unreliable results.
-version=0.4.1
+version=0.4.2
 qgisMinimumVersion=2.0
 
 # Optional items: