[processing] better expression context building

qgis · Apr 26, 2016 · 2535c0a · 2535c0a
1 parent e9a3089
commit 2535c0a
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Showing 3 changed files with 39 additions and 35 deletions.
diff --git a/python/plugins/processing/gui/AlgorithmDialog.py b/python/plugins/processing/gui/AlgorithmDialog.py
@@ -123,6 +123,7 @@ def setParamValues(self):
 
     def evaluateExpression(self, text):
         context = QgsExpressionContext()
+        context.appendScope(QgsExpressionContextUtils.globalScope())
         context.appendScope(QgsExpressionContextUtils.projectScope())
         exp = QgsExpression(text)
         if exp.hasParserError():

diff --git a/python/plugins/processing/gui/NumberInputPanel.py b/python/plugins/processing/gui/NumberInputPanel.py
@@ -33,7 +33,8 @@
 
 from math import log10, floor
 from qgis.core import (QgsDataSourceURI, QgsCredentials,  QgsExpressionContext,
-                        QgsExpressionContextUtils, QgsExpression, QgsRasterLayer)
+                        QgsExpressionContextUtils, QgsExpression, QgsRasterLayer,
+                        QgsExpressionContextScope)
 from qgis.gui import QgsEncodingFileDialog, QgsExpressionBuilderDialog
 from qgis.utils import iface
 from processing.tools import dataobjects
@@ -87,11 +88,7 @@ def __init__(self, number, minimum, maximum, isInteger):
         self.spnValue.valueChanged.connect(lambda: self.hasChanged.emit())
 
     def showExpressionsBuilder(self):
-        context = QgsExpressionContext()
-        context.appendScope(QgsExpressionContextUtils.globalScope())
-        scope = QgsExpressionContextUtils.projectScope()
-        self.addVariablesToScope(scope)
-        context.appendScope(scope)
+        context = self.expressionContext()
         dlg = QgsExpressionBuilderDialog(None, self.spnValue.text(), self, "generic", context)
         dlg.setWindowTitle(self.tr("Expression based input"));
         if dlg.exec_() == QDialog.Accepted:
@@ -104,40 +101,45 @@ def showExpressionsBuilder(self):
                     except:
                         pass
 
-    def addVariablesToScope(self, scope):
+    def expressionContext(self):
+        context = QgsExpressionContext()
+        context.appendScope(QgsExpressionContextUtils.globalScope())
+        context.appendScope(QgsExpressionContextUtils.projectScope())
+        processingScope = QgsExpressionContextScope()
         layers = dataobjects.getAllLayers()
         for layer in layers:
             name = layer.name()
-            scope.setVariable("%s_minx" % name, layer.extent().xMinimum())
-            scope.setVariable("%s_miny" % name, layer.extent().yMinimum())
-            scope.setVariable("%s_maxx" % name, layer.extent().xMaximum())
-            scope.setVariable("%s_maxy" % name, layer.extent().yMaximum())
+            processingScope.setVariable("%s_minx" % name, layer.extent().xMinimum())
+            processingScope.setVariable("%s_miny" % name, layer.extent().yMinimum())
+            processingScope.setVariable("%s_maxx" % name, layer.extent().xMaximum())
+            processingScope.setVariable("%s_maxy" % name, layer.extent().yMaximum())
             if isinstance(layer, QgsRasterLayer):
                 cellsize = (layer.extent().xMaximum()
                             - layer.extent().xMinimum()) / layer.width()
-                scope.setVariable("%s_cellsize" % name, cellsize)
+                processingScope.setVariable("%s_cellsize" % name, cellsize)
 
         layers = dataobjects.getRasterLayers()
         for layer in layers:
             for i in range(layer.bandCount()):
                 stats = layer.dataProvider().bandStatistics(i + 1)
-                scope.setVariable("%s_band%i_avg" % (name, i + 1), stats.mean)
-                scope.setVariable("%s_band%i_stddev" % (name, i + 1), stats.stdDev)
-                scope.setVariable("%s_band%i_min" % (name, i + 1), stats.minimumValue)
-                scope.setVariable("%s_band%i_max" % (name, i + 1), stats.maximumValue)
+                processingScope.setVariable("%s_band%i_avg" % (name, i + 1), stats.mean)
+                processingScope.setVariable("%s_band%i_stddev" % (name, i + 1), stats.stdDev)
+                processingScope.setVariable("%s_band%i_min" % (name, i + 1), stats.minimumValue)
+                processingScope.setVariable("%s_band%i_max" % (name, i + 1), stats.maximumValue)
 
         extent = iface.mapCanvas().extent()
-        scope.setVariable("canvasextent_minx", extent.xMinimum())
-        scope.setVariable("canvasextent_miny", extent.yMinimum())
-        scope.setVariable("canvasextent_maxx", extent.xMaximum())
-        scope.setVariable("canvasextent_maxy", extent.yMaximum())
+        processingScope.setVariable("canvasextent_minx", extent.xMinimum())
+        processingScope.setVariable("canvasextent_miny", extent.yMinimum())
+        processingScope.setVariable("canvasextent_maxx", extent.xMaximum())
+        processingScope.setVariable("canvasextent_maxy", extent.yMaximum())
 
         extent = iface.mapCanvas().fullExtent()
-        scope.setVariable("fullextent_minx", extent.xMinimum())
-        scope.setVariable("fullextent_miny", extent.yMinimum())
-        scope.setVariable("fullextent_maxx", extent.xMaximum())
-        scope.setVariable("fullextent_maxy", extent.yMaximum())
-
+        processingScope.setVariable("fullextent_minx", extent.xMinimum())
+        processingScope.setVariable("fullextent_miny", extent.yMinimum())
+        processingScope.setVariable("fullextent_maxx", extent.xMaximum())
+        processingScope.setVariable("fullextent_maxy", extent.yMaximum())
+        context.appendScope(processingScope)
+        return context
 
     def getValue(self):
         return self.spnValue.value()

diff --git a/python/plugins/processing/gui/OutputSelectionPanel.py b/python/plugins/processing/gui/OutputSelectionPanel.py
@@ -34,7 +34,7 @@
 from PyQt.QtGui import QCursor
 from qgis.gui import QgsEncodingFileDialog, QgsExpressionBuilderDialog
 from qgis.core import QgsDataSourceURI, QgsCredentials,  QgsExpressionContext,\
-                     QgsExpressionContextUtils, QgsExpression
+                     QgsExpressionContextUtils, QgsExpression, QgsExpressionContextScope
 
 from processing.core.ProcessingConfig import ProcessingConfig
 from processing.core.outputs import OutputVector
@@ -107,18 +107,20 @@ def selectOutput(self):
             popupMenu.exec_(QCursor.pos())
 
     def showExpressionsBuilder(self):
-        context = QgsExpressionContext()
-        context.appendScope(QgsExpressionContextUtils.globalScope())
-        scope = QgsExpressionContextUtils.projectScope()
-        self.addVariablesToScope(scope)
-        dlg = QgsExpressionBuilderDialog(None, self.leText.text(), self, "generic", context)
+        dlg = QgsExpressionBuilderDialog(None, self.leText.text(), self, "generic", self.expressionContext())
         dlg.setWindowTitle(self.tr("Expression based output"));
         if dlg.exec_() == QDialog.Accepted:
             self.leText.setText(dlg.expressionText())
 
-    def addVariablesToScope(self, scope):
+    def expressionContext(self):
+        context = QgsExpressionContext()
+        context.appendScope(QgsExpressionContextUtils.globalScope())
+        context.appendScope(QgsExpressionContextUtils.projectScope())
+        processingScope = QgsExpressionContextScope()
         for param in self.ag.parameters:
-            scope.setVariable("%s_value" % param.name, "")
+            processingScope.setVariable("%s_value" % param.name, "")
+        context.appendScope(processingScope)
+        return context
 
     def saveToTemporaryFile(self):
         self.leText.setText('')
@@ -222,8 +224,7 @@ def selectDirectory(self):
 
     def getValue(self):
         fileName = unicode(self.leText.text())
-        context = QgsExpressionContext()
-        context.appendScope(QgsExpressionContextUtils.projectScope())
+        context = self.expressionContext()
         exp = QgsExpression(fileName)
         if not exp.hasParserError():
             result =  exp.evaluate(context)