[processing] added support for expressions in some input params and o…

…utputs
qgis · Apr 25, 2016 · ac0bff3 · ac0bff3 · nyalldawson · May 19, 2016
1 parent a7c3861
commit ac0bff3
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Showing 3 changed files with 67 additions and 13 deletions.
diff --git a/python/plugins/processing/gui/AlgorithmDialog.py b/python/plugins/processing/gui/AlgorithmDialog.py
@@ -29,7 +29,7 @@
 from PyQt.QtWidgets import QMessageBox, QApplication, QPushButton, QWidget, QVBoxLayout
 from PyQt.QtGui import QCursor, QColor, QPalette
 
-from qgis.core import QgsMapLayerRegistry
+from qgis.core import QgsMapLayerRegistry, QgsExpressionContext, QgsExpressionContextUtils, QgsExpression
 
 from processing.core.ProcessingLog import ProcessingLog
 from processing.core.ProcessingConfig import ProcessingConfig
@@ -102,8 +102,8 @@ def setParamValues(self):
                 continue
             if not self.setParamValue(
                     param, self.mainWidget.valueItems[param.name]):
-                raise AlgorithmDialogBase.InvalidParameterValue(param,
-                                                                self.mainWidget.valueItems[param.name])
+                raise AlgorithmDialogBase.InvalidParameterValue(
+                    param, self.mainWidget.valueItems[param.name])
 
         for param in params:
             if isinstance(param, ParameterExtent):
@@ -121,6 +121,18 @@ def setParamValues(self):
 
         return True
 
+    def evaluateExpression(self, text):
+        context = QgsExpressionContext()
+        context.appendScope(QgsExpressionContextUtils.projectScope())
+        exp = QgsExpression(text)
+        if exp.hasParserError():
+            raise Exception(exp.parserErrorString())
+        result =  exp.evaluate(context)
+        if exp.hasEvalError():
+            raise ValueError(exp.evalErrorString())
+        return result
+
+
     def setParamValue(self, param, widget, alg=None):
         if isinstance(param, ParameterRaster):
             return param.setValue(widget.getValue())
@@ -159,7 +171,12 @@ def setParamValue(self, param, widget, alg=None):
             if param.multiline:
                 return param.setValue(unicode(widget.toPlainText()))
             else:
-                return param.setValue(unicode(widget.text()))
+                text = widget.text()
+                try:
+                    text = self.evaluateExpression(text)
+                except:
+                    return False
+                return param.setValue(text)
         elif isinstance(param, ParameterGeometryPredicate):
             return param.setValue(widget.value())
         else:

diff --git a/python/plugins/processing/gui/NumberInputPanel.py b/python/plugins/processing/gui/NumberInputPanel.py
@@ -29,9 +29,12 @@
 
 from PyQt import uic
 from PyQt.QtCore import pyqtSignal
+from PyQt.QtGui import QDialog
 
 from math import log10, floor
-from processing.gui.NumberInputDialog import NumberInputDialog
+from qgis.core import (QgsDataSourceURI, QgsCredentials,  QgsExpressionContext,
+                        QgsExpressionContextUtils, QgsExpression)
+from qgis.gui import QgsEncodingFileDialog, QgsExpressionBuilderDialog
 
 pluginPath = os.path.split(os.path.dirname(__file__))[0]
 WIDGET, BASE = uic.loadUiType(
@@ -46,6 +49,7 @@ def __init__(self, number, minimum, maximum, isInteger):
         super(NumberInputPanel, self).__init__(None)
         self.setupUi(self)
 
+        self.spnValue.setExpressionsEnabled(True)
         self.isInteger = isInteger
         if self.isInteger:
             self.spnValue.setDecimals(0)
@@ -74,15 +78,27 @@ def __init__(self, number, minimum, maximum, isInteger):
             self.spnValue.setValue(0)
             self.spnValue.setClearValue(0)
 
-        self.btnCalc.clicked.connect(self.showNumberInputDialog)
+        self.btnCalc.setFixedHeight(self.spnValue.height())
+
+        self.btnCalc.clicked.connect(self.showExpressionsBuilder)
 
         self.spnValue.valueChanged.connect(lambda: self.hasChanged.emit())
 
-    def showNumberInputDialog(self):
-        dlg = NumberInputDialog(self.isInteger)
-        dlg.exec_()
-        if dlg.value is not None:
-            self.spnValue.setValue(dlg.value)
+    def showExpressionsBuilder(self):
+        context = QgsExpressionContext()
+        context.appendScope(QgsExpressionContextUtils.globalScope())
+        context.appendScope(QgsExpressionContextUtils.projectScope())
+        dlg = QgsExpressionBuilderDialog(None, self.spnValue.text(), self, "generic", context)
+        dlg.setWindowTitle(self.tr("Expression based input"));
+        if dlg.exec_() == QDialog.Accepted:
+            exp = QgsExpression(dlg.expressionText())
+            if not exp.hasParserError():
+                result =  exp.evaluate(context)
+                if not exp.hasEvalError():
+                    try:
+                        self.spnValue.setValue(float(result))
+                    except:
+                        pass
 
     def getValue(self):
         return self.spnValue.value()

diff --git a/python/plugins/processing/gui/OutputSelectionPanel.py b/python/plugins/processing/gui/OutputSelectionPanel.py
@@ -32,8 +32,9 @@
 from PyQt.QtCore import QCoreApplication, QSettings
 from PyQt.QtWidgets import QDialog, QMenu, QAction, QFileDialog
 from PyQt.QtGui import QCursor
-from qgis.gui import QgsEncodingFileDialog
-from qgis.core import QgsDataSourceURI, QgsCredentials
+from qgis.gui import QgsEncodingFileDialog, QgsExpressionBuilderDialog
+from qgis.core import QgsDataSourceURI, QgsCredentials,  QgsExpressionContext,\
+                     QgsExpressionContextUtils, QgsExpression
 
 from processing.core.ProcessingConfig import ProcessingConfig
 from processing.core.outputs import OutputVector
@@ -78,6 +79,11 @@ def selectOutput(self):
             actionSaveToFile.triggered.connect(self.selectFile)
             popupMenu.addAction(actionSaveToFile)
 
+            actionShowExpressionsBuilder = QAction(
+                self.tr('Use expression...'), self.btnSelect)
+            actionShowExpressionsBuilder.triggered.connect(self.showExpressionsBuilder)
+            popupMenu.addAction(actionShowExpressionsBuilder)
+
             if isinstance(self.output, OutputVector) \
                     and self.alg.provider.supportsNonFileBasedOutput():
                 actionSaveToMemory = QAction(
@@ -100,6 +106,14 @@ def selectOutput(self):
 
             popupMenu.exec_(QCursor.pos())
 
+    def showExpressionsBuilder(self):
+        context = QgsExpressionContext()
+        context.appendScope(QgsExpressionContextUtils.projectScope())
+        dlg = QgsExpressionBuilderDialog(None, self.leText.text(), self, "generic", context)
+        dlg.setWindowTitle(self.tr("Expression based output"));
+        if dlg.exec_() == QDialog.Accepted:
+            self.leText.setText(dlg.expressionText())
+
     def saveToTemporaryFile(self):
         self.leText.setText('')
 
@@ -202,6 +216,13 @@ def selectDirectory(self):
 
     def getValue(self):
         fileName = unicode(self.leText.text())
+        context = QgsExpressionContext()
+        context.appendScope(QgsExpressionContextUtils.projectScope())
+        exp = QgsExpression(fileName)
+        if not exp.hasParserError():
+            result =  exp.evaluate(context)
+            if not exp.hasEvalError():
+                fileName = result
         if fileName.strip() in ['', self.SAVE_TO_TEMP_FILE]:
             value = None
         elif fileName.startswith('memory:'):