Python core.QgsExpressionContextScope类代码示例

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本文整理汇总了Python中qgis.core.QgsExpressionContextScope类的典型用法代码示例。如果您正苦于以下问题：Python QgsExpressionContextScope类的具体用法？Python QgsExpressionContextScope怎么用？Python QgsExpressionContextScope使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。

在下文中一共展示了QgsExpressionContextScope类的13个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的Python代码示例。

示例1: update_variables_gui

 def update_variables_gui(self):
     variables_scope = QgsExpressionContextScope(self.tr('Model Variables'))
     for k, v in self.model.variables().items():
         variables_scope.setVariable(k, v)
     variables_context = QgsExpressionContext()
     variables_context.appendScope(variables_scope)
     self.variables_editor.setContext(variables_context)
     self.variables_editor.setEditableScopeIndex(0)

开发者ID:dwsilk，项目名称:QGIS，代码行数:8，代码来源:ModelerDialog.py

示例2: _expressionContext

def _expressionContext(alg):
    context = QgsExpressionContext()
    context.appendScope(QgsExpressionContextUtils.globalScope())
    context.appendScope(QgsExpressionContextUtils.projectScope())
    processingScope = QgsExpressionContextScope()
    for param in alg.parameters:
        processingScope.setVariable('%s_value' % param.name, '')
    context.appendScope(processingScope)
    return context

开发者ID:spono，项目名称:QGIS，代码行数:9，代码来源:outputs.py

示例3: expressionContext

 def expressionContext(self):
     context = QgsExpressionContext()
     context.appendScope(QgsExpressionContextUtils.globalScope())
     context.appendScope(QgsExpressionContextUtils.projectScope())
     processingScope = QgsExpressionContextScope()
     for param in self.alg.parameters:
         processingScope.setVariable("%s_value" % param.name, "")
     context.appendScope(processingScope)
     return context

开发者ID:CS-SI，项目名称:QGIS，代码行数:9，代码来源:OutputSelectionPanel.py

示例4: check_for_update_events

    def check_for_update_events(self, widget, value):
        if not self.feature:
            return

        from qgis.core import QgsExpression, QgsExpressionContext, QgsExpressionContextScope
        # If we don't have any events for this widgets just get out now
        if not widget.id in self.events:
            return

        events = self.events[widget.id]
        events = [event for event in events if event['event'].lower() == 'update']
        if not events:
            return

        feature = self.to_feature(no_defaults=True)

        for event in events:
            action = event['action'].lower()
            targetid = event['target']
            if targetid == widget.id:
                utils.log("Can't connect events to the same widget. ID {}".format(targetid))
                continue

            widget = self.get_widget_from_id(targetid)

            if not widget:
                utils.log("Can't find widget for id {} in form".format(targetid))
                continue

            condition = event['condition']
            expression = event['value']

            context = QgsExpressionContext()
            scope = QgsExpressionContextScope()
            scope.setVariable("value", value)
            scope.setVariable("field", widget.field)
            context.setFeature(feature)
            context.appendScope(scope)

            conditionexp = QgsExpression(condition)
            exp = QgsExpression(expression)

            if action.lower() == "show":
                widget.hidden = not conditionexp.evaluate(context)
            if action.lower() == "hide":
                widget.hidden = conditionexp.evaluate(context)
            if action == 'widget expression':
                if conditionexp.evaluate(context):
                    newvalue = self.widget_default(field, feature=feature)
                    widget.setvalue(newvalue)
            if action == 'set value':
                if conditionexp.evaluate(context):
                    newvalue = exp.evaluate(context)
                    widget.setvalue(newvalue)

开发者ID:skeenp，项目名称:Roam，代码行数:54，代码来源:featureform.py

示例5: createExpressionContext

def createExpressionContext():
    context = QgsExpressionContext()
    context.appendScope(QgsExpressionContextUtils.globalScope())
    context.appendScope(QgsExpressionContextUtils.projectScope(QgsProject.instance()))

    if iface.mapCanvas():
        context.appendScope(QgsExpressionContextUtils.mapSettingsScope(iface.mapCanvas().mapSettings()))

    processingScope = QgsExpressionContextScope()

    extent = iface.mapCanvas().fullExtent()
    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

开发者ID:rskelly，项目名称:QGIS，代码行数:17，代码来源:dataobjects.py

示例6: testVariables

    def testVariables(self):
        """ check through widget model to ensure it is populated with variables """
        w = QgsExpressionBuilderWidget()
        m = w.model()

        s = QgsExpressionContextScope()
        s.setVariable('my_var1', 'x')
        s.setVariable('my_var2', 'y')
        c = QgsExpressionContext()
        c.appendScope(s)

        # check that variables are added when setting context
        w.setExpressionContext(c)
        items = m.findItems('my_var1', Qt.MatchRecursive)
        self.assertEqual(len(items), 1)
        items = m.findItems('my_var2', Qt.MatchRecursive)
        self.assertEqual(len(items), 1)
        items = m.findItems('not_my_var', Qt.MatchRecursive)
        self.assertEqual(len(items), 0)
        # double check that functions are still only there once
        items = m.findItems('lower', Qt.MatchRecursive)
        self.assertEqual(len(items), 1)
        items = m.findItems('upper', Qt.MatchRecursive)
        self.assertEqual(len(items), 1)

开发者ID:giohappy，项目名称:QGIS，代码行数:24，代码来源:test_qgsexpressionbuilderwidget.py

示例7: init

    def __init__(self, dialog):
        super(ExecuteSQLWidget, self).__init__(None)
        self.setupUi(self)
        self.dialog = dialog
        self.dialogType = dialogTypes[dialog.__class__.__name__]

        self.mExpressionWidget = QgsFieldExpressionWidget()

        # add model parameters in context scope if called from modeler
        if self.dialogType == DIALOG_MODELER:
            strings = dialog.getAvailableValuesOfType(
                [QgsProcessingParameterString, QgsProcessingParameterNumber], [])
            model_params = [dialog.resolveValueDescription(s) for s in strings]

            scope = QgsExpressionContextScope()
            for param in model_params:
                var = QgsExpressionContextScope.StaticVariable(param)
                scope.addVariable(var)

            self.mExpressionWidget.appendScope(scope)

        self.mHLayout.insertWidget(0, self.mExpressionWidget)

        self.mInsert.clicked.connect(self.insert)

开发者ID:mbernasocchi，项目名称:QGIS，代码行数:24，代码来源:ExecuteSQLWidget.py

示例8: testExpression

    def testExpression(self):
        """ test aggregate calculation using an expression """

        # numeric
        layer = QgsVectorLayer("Point?field=fldint:integer", "layer", "memory")
        pr = layer.dataProvider()

        int_values = [4, 2, 3, 2, 5, None, 8]

        features = []
        for v in int_values:
            f = QgsFeature()
            f.setFields(layer.fields())
            f.setAttributes([v])
            features.append(f)
        assert pr.addFeatures(features)

        #int
        agg = QgsAggregateCalculator(layer)
        val, ok = agg.calculate(QgsAggregateCalculator.Sum, 'fldint * 2')
        self.assertTrue(ok)
        self.assertEqual(val, 48)

        # double
        val, ok = agg.calculate(QgsAggregateCalculator.Sum, 'fldint * 1.5')
        self.assertTrue(ok)
        self.assertEqual(val, 36)

        # datetime
        val, ok = agg.calculate(QgsAggregateCalculator.Max, "to_date('2012-05-04') + to_interval( fldint || ' day' )")
        self.assertTrue(ok)
        self.assertEqual(val, QDateTime(QDate(2012, 5, 12), QTime(0, 0, 0)))

        # date
        val, ok = agg.calculate(QgsAggregateCalculator.Min, "to_date(to_date('2012-05-04') + to_interval( fldint || ' day' ))")
        self.assertTrue(ok)
        self.assertEqual(val, QDateTime(QDate(2012, 5, 6), QTime(0, 0, 0)))

        # string
        val, ok = agg.calculate(QgsAggregateCalculator.Max, "fldint || ' oranges'")
        self.assertTrue(ok)
        self.assertEqual(val, '8 oranges')

        # geometry
        val, ok = agg.calculate(QgsAggregateCalculator.GeometryCollect, "make_point( coalesce(fldint,0), 2 )")
        self.assertTrue(ok)
        self.assertTrue(val.exportToWkt(), 'MultiPoint((4 2, 2 2, 3 2, 2 2,5 2, 0 2,8 2))')

        # try a bad expression
        val, ok = agg.calculate(QgsAggregateCalculator.Max, "not_a_field || ' oranges'")
        self.assertFalse(ok)
        val, ok = agg.calculate(QgsAggregateCalculator.Max, "5+")
        self.assertFalse(ok)

        # test expression context

        # check default context first
        # should have layer variables:
        val, ok = agg.calculate(QgsAggregateCalculator.Min, "@layer_name")
        self.assertTrue(ok)
        self.assertEqual(val, 'layer')
        # but not custom variables:
        val, ok = agg.calculate(QgsAggregateCalculator.Min, "@my_var")
        self.assertTrue(ok)
        self.assertEqual(val, NULL)

        # test with manual expression context
        scope = QgsExpressionContextScope()
        scope.setVariable('my_var', 5)
        context = QgsExpressionContext()
        context.appendScope(scope)
        val, ok = agg.calculate(QgsAggregateCalculator.Min, "@my_var", context)
        self.assertTrue(ok)
        self.assertEqual(val, 5)

开发者ID:GrokImageCompression，项目名称:QGIS，代码行数:74，代码来源:test_qgsaggregatecalculator.py

示例9: expressionContext

    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()
            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()
                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)
                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()
        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()
        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

开发者ID:AM7000000，项目名称:QGIS，代码行数:39，代码来源:NumberInputPanel.py

示例10: runGetFeatureTests

    def runGetFeatureTests(self, provider):
        assert len([f for f in provider.getFeatures()]) == 5
        self.assert_query(provider, 'name ILIKE \'QGIS\'', [])
        self.assert_query(provider, '"name" IS NULL', [5])
        self.assert_query(provider, '"name" IS NOT NULL', [1, 2, 3, 4])
        self.assert_query(provider, '"name" NOT LIKE \'Ap%\'', [1, 3, 4])
        self.assert_query(provider, '"name" NOT ILIKE \'QGIS\'', [1, 2, 3, 4])
        self.assert_query(provider, '"name" NOT ILIKE \'pEAR\'', [1, 2, 4])
        self.assert_query(provider, 'name = \'Apple\'', [2])
        self.assert_query(provider, 'name <> \'Apple\'', [1, 3, 4])
        self.assert_query(provider, 'name = \'apple\'', [])
        self.assert_query(provider, '"name" <> \'apple\'', [1, 2, 3, 4])
        self.assert_query(provider, '(name = \'Apple\') is not null', [1, 2, 3, 4])
        self.assert_query(provider, 'name LIKE \'Apple\'', [2])
        self.assert_query(provider, 'name LIKE \'aPple\'', [])
        self.assert_query(provider, 'name ILIKE \'aPple\'', [2])
        self.assert_query(provider, 'name ILIKE \'%pp%\'', [2])
        self.assert_query(provider, 'cnt > 0', [1, 2, 3, 4])
        self.assert_query(provider, '-cnt > 0', [5])
        self.assert_query(provider, 'cnt < 0', [5])
        self.assert_query(provider, '-cnt < 0', [1, 2, 3, 4])
        self.assert_query(provider, 'cnt >= 100', [1, 2, 3, 4])
        self.assert_query(provider, 'cnt <= 100', [1, 5])
        self.assert_query(provider, 'pk IN (1, 2, 4, 8)', [1, 2, 4])
        self.assert_query(provider, 'cnt = 50 * 2', [1])
        self.assert_query(provider, 'cnt = 99 + 1', [1])
        self.assert_query(provider, 'cnt = 101 - 1', [1])
        self.assert_query(provider, 'cnt - 1 = 99', [1])
        self.assert_query(provider, '-cnt - 1 = -101', [1])
        self.assert_query(provider, '-(-cnt) = 100', [1])
        self.assert_query(provider, '-(cnt) = -(100)', [1])
        self.assert_query(provider, 'cnt + 1 = 101', [1])
        self.assert_query(provider, 'cnt = 1100 % 1000', [1])
        self.assert_query(provider, '"name" || \' \' || "name" = \'Orange Orange\'', [1])
        self.assert_query(provider, '"name" || \' \' || "cnt" = \'Orange 100\'', [1])
        self.assert_query(provider, '\'x\' || "name" IS NOT NULL', [1, 2, 3, 4])
        self.assert_query(provider, '\'x\' || "name" IS NULL', [5])
        self.assert_query(provider, 'cnt = 10 ^ 2', [1])
        self.assert_query(provider, '"name" ~ \'[OP]ra[gne]+\'', [1])
        self.assert_query(provider, '"name"="name2"', [2, 4])  # mix of matched and non-matched case sensitive names
        self.assert_query(provider, 'true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'false', [])

        # Three value logic
        self.assert_query(provider, 'false and false', [])
        self.assert_query(provider, 'false and true', [])
        self.assert_query(provider, 'false and NULL', [])
        self.assert_query(provider, 'true and false', [])
        self.assert_query(provider, 'true and true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'true and NULL', [])
        self.assert_query(provider, 'NULL and false', [])
        self.assert_query(provider, 'NULL and true', [])
        self.assert_query(provider, 'NULL and NULL', [])
        self.assert_query(provider, 'false or false', [])
        self.assert_query(provider, 'false or true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'false or NULL', [])
        self.assert_query(provider, 'true or false', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'true or true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'true or NULL', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'NULL or false', [])
        self.assert_query(provider, 'NULL or true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'NULL or NULL', [])
        self.assert_query(provider, 'not true', [])
        self.assert_query(provider, 'not false', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'not null', [])

        # not
        self.assert_query(provider, 'not name = \'Apple\'', [1, 3, 4])
        self.assert_query(provider, 'not name IS NULL', [1, 2, 3, 4])
        self.assert_query(provider, 'not name = \'Apple\' or name = \'Apple\'', [1, 2, 3, 4])
        self.assert_query(provider, 'not name = \'Apple\' or not name = \'Apple\'', [1, 3, 4])
        self.assert_query(provider, 'not name = \'Apple\' and pk = 4', [4])
        self.assert_query(provider, 'not name = \'Apple\' and not pk = 4', [1, 3])
        self.assert_query(provider, 'not pk IN (1, 2, 4, 8)', [3, 5])

        # type conversion - QGIS expressions do not mind that we are comparing a string
        # against numeric literals
        self.assert_query(provider, 'num_char IN (2, 4, 5)', [2, 4, 5])

        # geometry
        self.assert_query(provider, 'intersects($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))', [1, 2])

        # combination of an uncompilable expression and limit
        feature = next(self.vl.getFeatures('pk=4'))
        context = QgsExpressionContext()
        scope = QgsExpressionContextScope()
        scope.setVariable('parent', feature)
        context.appendScope(scope)

        request = QgsFeatureRequest()
        request.setExpressionContext(context)
        request.setFilterExpression('"pk" = attribute(@parent, \'pk\')')
        request.setLimit(1)

        values = [f['pk'] for f in self.vl.getFeatures(request)]
        self.assertEqual(values, [4])

开发者ID:medspx，项目名称:QGIS，代码行数:96，代码来源:providertestbase.py

示例11: runGetFeatureTests


#.........这里部分代码省略.........
        self.assert_query(provider, 'false', [])

        # Three value logic
        self.assert_query(provider, 'false and false', [])
        self.assert_query(provider, 'false and true', [])
        self.assert_query(provider, 'false and NULL', [])
        self.assert_query(provider, 'true and false', [])
        self.assert_query(provider, 'true and true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'true and NULL', [])
        self.assert_query(provider, 'NULL and false', [])
        self.assert_query(provider, 'NULL and true', [])
        self.assert_query(provider, 'NULL and NULL', [])
        self.assert_query(provider, 'false or false', [])
        self.assert_query(provider, 'false or true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'false or NULL', [])
        self.assert_query(provider, 'true or false', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'true or true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'true or NULL', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'NULL or false', [])
        self.assert_query(provider, 'NULL or true', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'NULL or NULL', [])
        self.assert_query(provider, 'not true', [])
        self.assert_query(provider, 'not false', [1, 2, 3, 4, 5])
        self.assert_query(provider, 'not null', [])

        # not
        self.assert_query(provider, 'not name = \'Apple\'', [1, 3, 4])
        self.assert_query(provider, 'not name IS NULL', [1, 2, 3, 4])
        self.assert_query(provider, 'not name = \'Apple\' or name = \'Apple\'', [1, 2, 3, 4])
        self.assert_query(provider, 'not name = \'Apple\' or not name = \'Apple\'', [1, 3, 4])
        self.assert_query(provider, 'not name = \'Apple\' and pk = 4', [4])
        self.assert_query(provider, 'not name = \'Apple\' and not pk = 4', [1, 3])
        self.assert_query(provider, 'not pk IN (1, 2, 4, 8)', [3, 5])

        # type conversion - QGIS expressions do not mind that we are comparing a string
        # against numeric literals
        self.assert_query(provider, 'num_char IN (2, 4, 5)', [2, 4, 5])

        #function
        self.assert_query(provider, 'sqrt(pk) >= 2', [4, 5])
        self.assert_query(provider, 'radians(cnt) < 2', [1, 5])
        self.assert_query(provider, 'degrees(pk) <= 200', [1, 2, 3])
        self.assert_query(provider, 'abs(cnt) <= 200', [1, 2, 5])
        self.assert_query(provider, 'cos(pk) < 0', [2, 3, 4])
        self.assert_query(provider, 'sin(pk) < 0', [4, 5])
        self.assert_query(provider, 'tan(pk) < 0', [2, 3, 5])
        self.assert_query(provider, 'acos(-1) < pk', [4, 5])
        self.assert_query(provider, 'asin(1) < pk', [2, 3, 4, 5])
        self.assert_query(provider, 'atan(3.14) < pk', [2, 3, 4, 5])
        self.assert_query(provider, 'atan2(3.14, pk) < 1', [3, 4, 5])
        self.assert_query(provider, 'exp(pk) < 10', [1, 2])
        self.assert_query(provider, 'ln(pk) <= 1', [1, 2])
        self.assert_query(provider, 'log(3, pk) <= 1', [1, 2, 3])
        self.assert_query(provider, 'log10(pk) < 0.5', [1, 2, 3])
        self.assert_query(provider, 'round(3.14) <= pk', [3, 4, 5])
        self.assert_query(provider, 'round(0.314,1) * 10 = pk', [3])
        self.assert_query(provider, 'floor(3.14) <= pk', [3, 4, 5])
        self.assert_query(provider, 'ceil(3.14) <= pk', [4, 5])
        self.assert_query(provider, 'pk < pi()', [1, 2, 3])

        self.assert_query(provider, 'round(cnt / 66.67) <= 2', [1, 5])
        self.assert_query(provider, 'floor(cnt / 66.67) <= 2', [1, 2, 5])
        self.assert_query(provider, 'ceil(cnt / 66.67) <= 2', [1, 5])
        self.assert_query(provider, 'pk < pi() / 2', [1])
        self.assert_query(provider, 'pk = char(51)', [3])
        self.assert_query(provider, 'pk = coalesce(NULL,3,4)', [3])
        self.assert_query(provider, 'lower(name) = \'apple\'', [2])
        self.assert_query(provider, 'upper(name) = \'APPLE\'', [2])
        self.assert_query(provider, 'name = trim(\'   Apple   \')', [2])

        # geometry
        # azimuth and touches tests are deactivated because they do not pass for WFS provider
        #self.assert_query(provider, 'azimuth($geometry,geom_from_wkt( \'Point (-70 70)\')) < pi()', [1, 5])
        self.assert_query(provider, 'x($geometry) < -70', [1, 5])
        self.assert_query(provider, 'y($geometry) > 70', [2, 4, 5])
        self.assert_query(provider, 'xmin($geometry) < -70', [1, 5])
        self.assert_query(provider, 'ymin($geometry) > 70', [2, 4, 5])
        self.assert_query(provider, 'xmax($geometry) < -70', [1, 5])
        self.assert_query(provider, 'ymax($geometry) > 70', [2, 4, 5])
        self.assert_query(provider, 'disjoint($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))', [4, 5])
        self.assert_query(provider, 'intersects($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))', [1, 2])
        #self.assert_query(provider, 'touches($geometry,geom_from_wkt( \'Polygon ((-70.332 66.33, -65.32 66.33, -65.32 78.3, -70.332 78.3, -70.332 66.33))\'))', [1, 4])
        self.assert_query(provider, 'contains(geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'),$geometry)', [1, 2])
        self.assert_query(provider, 'distance($geometry,geom_from_wkt( \'Point (-70 70)\')) > 7', [4, 5])
        self.assert_query(provider, 'intersects($geometry,geom_from_gml( \'<gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>-72.2,66.1 -65.2,66.1 -65.2,72.0 -72.2,72.0 -72.2,66.1</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon>\'))', [1, 2])

        # combination of an uncompilable expression and limit
        feature = next(self.vl.getFeatures('pk=4'))
        context = QgsExpressionContext()
        scope = QgsExpressionContextScope()
        scope.setVariable('parent', feature)
        context.appendScope(scope)

        request = QgsFeatureRequest()
        request.setExpressionContext(context)
        request.setFilterExpression('"pk" = attribute(@parent, \'pk\')')
        request.setLimit(1)

        values = [f['pk'] for f in self.vl.getFeatures(request)]
        self.assertEqual(values, [4])

开发者ID:wongjimsan，项目名称:QGIS，代码行数:101，代码来源:providertestbase.py

示例12: layer_value

def layer_value(feature, layer, defaultconfig):
    if not canvas:
        roam.utils.warning("No canvas set for using layer_values default function")
        return None
    layers = []
    # layer name can also be a list of layers to search
    layername = defaultconfig['layer']
    if isinstance(layername, basestring):
        layers.append(layername)
    else:
        layers = layername

    expression = defaultconfig['expression']
    field = defaultconfig['field']

    for searchlayer in layers:
        try:
            searchlayer = QgsMapLayerRegistry.instance().mapLayersByName(searchlayer)[0]
        except IndexError:
            RoamEvents.raisemessage("Missing layer",
                                    "Unable to find layer used in widget expression {}".format(searchlayer),
                                    level=1)
            roam.utils.warning("Unable to find expression layer {}".format(searchlayer))
            return
        if feature.geometry():
            rect = feature.geometry().boundingBox()
            if layer.geometryType() == QGis.Point:
                point = feature.geometry().asPoint()
                rect = QgsRectangle(point.x(), point.y(), point.x() + 10, point.y() + 10)

            rect.scale(20)

            rect = canvas.mapRenderer().mapToLayerCoordinates(layer, rect)
            rq = QgsFeatureRequest().setFilterRect(rect)\
                                    .setFlags(QgsFeatureRequest.ExactIntersect)
            features = searchlayer.getFeatures(rq)
        else:
            features = searchlayer.getFeatures()

        expression = expression.replace("$roamgeometry", "@roamgeometry")

        exp = QgsExpression(expression)
        exp.prepare(searchlayer.pendingFields())
        if exp.hasParserError():
            error = exp.parserErrorString()
            roam.utils.warning(error)

        context = QgsExpressionContext()
        scope = QgsExpressionContextScope()
        context.appendScope(scope)
        scope.setVariable("roamgeometry", feature.geometry())

        for f in features:
            context.setFeature(f)
            value = exp.evaluate(context)
            if exp.hasEvalError():
                error = exp.evalErrorString()
                roam.utils.warning(error)
            if value:
                return f[field]

    raise DefaultError('No features found')

开发者ID:skeenp，项目名称:Roam，代码行数:62，代码来源:defaults.py

示例13: processAlgorithm

    def processAlgorithm(self, parameters, context, feedback):
        source = self.parameterAsRasterLayer(parameters, self.INPUT, context)
        if source is None:
            raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
            
        band = self.parameterAsInt(parameters, self.BAND, context)
        expression = self.parameterAsString(parameters, self.EXPRESSION, context).replace('\n', '')
        feedback.pushInfo('Expression = {}'.format(expression))
        if len(expression.strip()) == 0:
            raise QgsProcessingException('Expression values required!')
        
        output_raster = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
        
        # create raster dataset
        inputDs = gdal.Open(unicode(source.source()), GA_ReadOnly)
        inputBand = inputDs.GetRasterBand(band)
        dataType = inputBand.DataType;
        nodata = int(inputBand.GetNoDataValue()) if dataType < 6 else inputBand.GetNoDataValue()
        
        feedback.pushInfo('NoData Value = {0}'.format(nodata))
        feedback.pushInfo('DataType = {0}'.format(dataType))
        feedback.pushInfo('DataType = {0}'.format(self.RASTER_TYPES[gdal.GetDataTypeName(dataType)]))

        driver = gdal.GetDriverByName('GTiff')
        outputDs = driver.Create(output_raster, inputDs.RasterXSize, inputDs.RasterYSize, 1, dataType)
        outputDs.SetProjection(inputDs.GetProjection())
        outputDs.SetGeoTransform(inputDs.GetGeoTransform())
        outputBand = outputDs.GetRasterBand(1)
        outputBand.SetNoDataValue(nodata)

        # prepare feature for expression
        fields = QgsFields()
        fields.append(QgsField('value', QVariant.Double))
        fields.append(QgsField(source.name(), QVariant.Double))

        exp = QgsExpression(expression)
        context = QgsExpressionContext()
        scope = QgsExpressionContextScope()
        context.appendScope(scope)

        feature = QgsFeature(fields)

        # extrace by attributes
        data_type  = self.RASTER_TYPES[gdal.GetDataTypeName(dataType)]
        for y in range(inputBand.YSize):
            if feedback.isCanceled():
                break
            feedback.setProgress(int(y / float(inputBand.YSize) * 100))
            
            scanline = inputBand.ReadRaster(0, y, inputBand.XSize, 1, inputBand.XSize, 1, dataType)
            values = struct.unpack(data_type * inputBand.XSize, scanline)
            
            output = ''.encode()
            for value in values:
                raster_value = nodata
                if value != nodata:
                    feature.setAttribute(0, value)
                    feature.setAttribute(1, value)
                    scope.setFeature(feature)
                    if bool(exp.evaluate(context)):
                      raster_value = value
                    else:
                      raster_value = nodata
                output = output + struct.pack(data_type, raster_value)
                    
            # write line
            outputBand.WriteRaster(0, y, inputBand.XSize, 1, output, buf_xsize=inputBand.XSize, buf_ysize=1, buf_type=dataType)
            del output

        outputDs.FlushCache()
        outputDs = None
        inputDs = None

        return {self.OUTPUT: output_raster}

开发者ID:mapplus，项目名称:qgis-scripts，代码行数:74，代码来源:RasterExtractByAttributes.py

注：本文中的qgis.core.QgsExpressionContextScope类示例由纯净天空整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。

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Python core.QgsExpressionContextScope类代码示例

示例1: update_variables_gui

示例2: _expressionContext

示例3: expressionContext

示例4: check_for_update_events

示例5: createExpressionContext

示例6: testVariables

示例7: init

示例8: testExpression

示例9: expressionContext

示例10: runGetFeatureTests

示例11: runGetFeatureTests

示例12: layer_value

示例13: processAlgorithm

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Python core.QgsExpressionContextScope类代码示例

示例1: update_variables_gui

示例2: _expressionContext

示例3: expressionContext

示例4: check_for_update_events

示例5: createExpressionContext

示例6: testVariables

示例7: __init__

示例8: testExpression

示例9: expressionContext

示例10: runGetFeatureTests

示例11: runGetFeatureTests

示例12: layer_value

示例13: processAlgorithm

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Python util.grid_equal函数代码示例

Python util.get_worker_name函数代码示例

Python util.get_webmention_target函数代

Python util.get_uuid函数代码示例

Python util.get_type_by_name函数代码示例

Python util.grid_equal函数代码示例

Python util.get_worker_name函数代码示例

Python util.get_webmention_target函数代

Python util.get_uuid函数代码示例

Python util.get_type_by_name函数代码示例

Python util.get_stdout函数代码示例

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示例7: init