[feature] qgis_process now supports running a Python script algorithm

directly by specifying the path to the .py file in place of an algorithm ID or model file path
qgis · Dec 15, 2021 · d0718cb · d0718cb
1 parent dde113d
commit d0718cb
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Showing 6 changed files with 164 additions and 6 deletions.
diff --git a/python/plugins/processing/script/ScriptAlgorithmProvider.py b/python/plugins/processing/script/ScriptAlgorithmProvider.py
@@ -49,7 +49,7 @@ class ScriptAlgorithmProvider(QgsProcessingProvider):
     def __init__(self):
         super().__init__()
         self.algs = []
-        self.folder_algorithms = []
+        self.additional_algorithm_classes = []
         self.actions = [CreateNewScriptAction(),
                         AddScriptFromTemplateAction(),
                         OpenScriptFromFileAction(),
@@ -100,6 +100,13 @@ def supportsNonFileBasedOutput(self):
         # they'll get an error if they use them with incompatible outputs...
         return True
 
+    def add_algorithm_class(self, algorithm_class):
+        """
+        Adds an algorithm class to the provider
+        """
+        self.additional_algorithm_classes.append(algorithm_class)
+        self.refreshAlgorithms()
+
     def loadAlgorithms(self):
         self.algs = []
         folders = ScriptUtils.scriptsFolders()
@@ -122,5 +129,8 @@ def loadAlgorithms(self):
                         if alg is not None:
                             self.algs.append(alg)
 
+        for alg_class in self.additional_algorithm_classes:
+            self.algs.append(alg_class())
+
         for a in self.algs:
             self.addAlgorithm(a)
diff --git a/src/process/qgsprocess.cpp b/src/process/qgsprocess.cpp
@@ -460,7 +460,7 @@ void QgsProcessingExec::showUsage( const QString &appName )
 
   msg << "QGIS Processing Executor - " << VERSION << " '" << RELEASE_NAME << "' ("
       << Qgis::version() << ")\n"
-      << "Usage: " << appName <<  " [--help] [--version] [--json] [--verbose] [command] [algorithm id or path to model file] [parameters]\n"
+      << "Usage: " << appName <<  " [--help] [--version] [--json] [--verbose] [command] [algorithm id, path to model file, or path to Python script] [parameters]\n"
       << "\nOptions:\n"
       << "\t--help or -h\t\tOutput the help\n"
       << "\t--version or -v\t\tOutput all versions related to QGIS Process\n"
@@ -679,8 +679,10 @@ int QgsProcessingExec::enablePlugin( const QString &name, bool enabled )
 #endif
 }
 
-int QgsProcessingExec::showAlgorithmHelp( const QString &id, bool useJson )
+int QgsProcessingExec::showAlgorithmHelp( const QString &inputId, bool useJson )
 {
+  QString id = inputId;
+
   std::unique_ptr< QgsProcessingModelAlgorithm > model;
   const QgsProcessingAlgorithm *alg = nullptr;
   if ( QFile::exists( id ) && QFileInfo( id ).suffix() == QLatin1String( "model3" ) )
@@ -694,7 +696,19 @@ int QgsProcessingExec::showAlgorithmHelp( const QString &id, bool useJson )
 
     alg = model.get();
   }
-  else
+  else if ( mPythonUtils && QFile::exists( id ) && QFileInfo( id ).suffix() == QLatin1String( "py" ) )
+  {
+    QString res;
+    if ( !mPythonUtils->evalString( QStringLiteral( "qgis.utils.import_script_algorithm(\"%1\")" ).arg( id ), res ) || res.isEmpty() )
+    {
+      std::cerr << QStringLiteral( "File %1 is not a valid Processing script!\n" ).arg( id ).toLocal8Bit().constData();
+      return 1;
+    }
+
+    id = res;
+  }
+
+  if ( !alg )
   {
     alg = QgsApplication::processingRegistry()->algorithmById( id );
     if ( ! alg )
@@ -861,14 +875,16 @@ int QgsProcessingExec::showAlgorithmHelp( const QString &id, bool useJson )
   return 0;
 }
 
-int QgsProcessingExec::execute( const QString &id, const QVariantMap &params, const QString &ellipsoid, QgsUnitTypes::DistanceUnit distanceUnit, QgsUnitTypes::AreaUnit areaUnit, QgsProcessingContext::LogLevel logLevel, bool useJson, const QString &projectPath )
+int QgsProcessingExec::execute( const QString &inputId, const QVariantMap &params, const QString &ellipsoid, QgsUnitTypes::DistanceUnit distanceUnit, QgsUnitTypes::AreaUnit areaUnit, QgsProcessingContext::LogLevel logLevel, bool useJson, const QString &projectPath )
 {
   QVariantMap json;
   if ( useJson )
   {
     addVersionInformation( json );
   }
 
+  QString id = inputId;
+
   std::unique_ptr< QgsProcessingModelAlgorithm > model;
   const QgsProcessingAlgorithm *alg = nullptr;
   if ( QFile::exists( id ) && QFileInfo( id ).suffix() == QLatin1String( "model3" ) )
@@ -882,7 +898,19 @@ int QgsProcessingExec::execute( const QString &id, const QVariantMap &params, co
 
     alg = model.get();
   }
-  else
+  else if ( mPythonUtils && QFile::exists( id ) && QFileInfo( id ).suffix() == QLatin1String( "py" ) )
+  {
+    QString res;
+    if ( !mPythonUtils->evalString( QStringLiteral( "qgis.utils.import_script_algorithm(\"%1\")" ).arg( id ), res ) || res.isEmpty() )
+    {
+      std::cerr << QStringLiteral( "File %1 is not a valid Processing script!\n" ).arg( id ).toLocal8Bit().constData();
+      return 1;
+    }
+
+    id = res;
+  }
+
+  if ( !alg )
   {
     alg = QgsApplication::processingRegistry()->algorithmById( id );
     if ( ! alg )

diff --git a/tests/src/python/test_qgsprocessexecutable.py b/tests/src/python/test_qgsprocessexecutable.py
@@ -286,6 +286,60 @@ def testModelRunWithLog(self):
 
         self.assertIn('Test logged message', lines)
 
+    def testPythonScriptHelp(self):
+        rc, output, err = self.run_process(['help', TEST_DATA_DIR + '/convert_to_upper.py'])
+        if os.environ.get('TRAVIS', '') != 'true':
+            # Travis DOES have errors, due to QStandardPaths: XDG_RUNTIME_DIR not set warnings raised by Qt
+            self.assertFalse(err)
+        self.assertEqual(rc, 0)
+        self.assertIn('converts a string to upper case', output.lower())
+
+    def testPythonScriptRun(self):
+        rc, output, err = self.run_process(['run', TEST_DATA_DIR + '/convert_to_upper.py', '--', 'INPUT=abc'])
+        if os.environ.get('TRAVIS', '') != 'true':
+            # Travis DOES have errors, due to QStandardPaths: XDG_RUNTIME_DIR not set warnings raised by Qt
+            self.assertFalse(err)
+        self.assertEqual(rc, 0)
+        self.assertIn('Converted abc to ABC', output)
+        self.assertIn('OUTPUT:\tABC', output)
+
+    def testPythonScriptRunJson(self):
+        rc, output, err = self.run_process(['run', TEST_DATA_DIR + '/convert_to_upper.py', '--json', '--', 'INPUT=abc'])
+        if os.environ.get('TRAVIS', '') != 'true':
+            # Travis DOES have errors, due to QStandardPaths: XDG_RUNTIME_DIR not set warnings raised by Qt
+            self.assertFalse(err)
+        self.assertEqual(rc, 0)
+
+        res = json.loads(output)
+        self.assertIn('gdal_version', res)
+        self.assertIn('geos_version', res)
+        self.assertIn('proj_version', res)
+        self.assertIn('python_version', res)
+        self.assertIn('qt_version', res)
+        self.assertIn('qgis_version', res)
+        self.assertEqual(res['algorithm_details']['id'], 'script:converttouppercase')
+        self.assertEqual(res['results']['OUTPUT'], 'ABC')
+
+    def testPythonScriptRunNotAlgorithm(self):
+        rc, output, err = self.run_process(['run', TEST_DATA_DIR + '/not_a_processing_script.py'])
+        self.assertEqual(rc, 1)
+        self.assertIn('is not a valid Processing script', err)
+
+    def testPythonScriptHelpNotAlgorithm(self):
+        rc, output, err = self.run_process(['help', TEST_DATA_DIR + '/not_a_processing_script.py'])
+        self.assertEqual(rc, 1)
+        self.assertIn('is not a valid Processing script', err)
+
+    def testPythonScriptRunError(self):
+        rc, output, err = self.run_process(['run', TEST_DATA_DIR + '/script_with_error.py'])
+        self.assertEqual(rc, 1)
+        self.assertIn('is not a valid Processing script', err)
+
+    def testPythonScriptHelpError(self):
+        rc, output, err = self.run_process(['help', TEST_DATA_DIR + '/script_with_error.py'])
+        self.assertEqual(rc, 1)
+        self.assertIn('is not a valid Processing script', err)
+
 
 if __name__ == '__main__':
     # look for qgis bin path

diff --git a/tests/testdata/convert_to_upper.py b/tests/testdata/convert_to_upper.py
@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+from qgis.PyQt.QtCore import QCoreApplication
+from qgis.core import (QgsProcessing,
+                       QgsFeatureSink,
+                       QgsProcessingException,
+                       QgsProcessingAlgorithm,
+                       QgsProcessingParameterString,
+                       QgsProcessingOutputString)
+
+
+class ConvertStringToUppercase(QgsProcessingAlgorithm):
+    INPUT = 'INPUT'
+    OUTPUT = 'OUTPUT'
+
+    def createInstance(self):
+        return ConvertStringToUppercase()
+
+    def name(self):
+        return 'converttouppercase'
+
+    def displayName(self):
+        return 'Convert to upper'
+
+    def shortDescription(self):
+        return 'Converts a string to upper case'
+
+    def initAlgorithm(self, config=None):
+        self.addParameter(
+            QgsProcessingParameterString(
+                self.INPUT,
+                'Input string'
+            )
+        )
+
+        self.addOutput(
+            QgsProcessingOutputString(
+                self.OUTPUT,
+                'Output string'
+            )
+        )
+
+    def processAlgorithm(self, parameters, context, feedback):
+        input_string = self.parameterAsString(parameters, self.INPUT, context)
+        output_string = input_string.upper()
+        feedback.pushInfo('Converted {} to {}'.format(input_string, output_string))
+        return {self.OUTPUT: output_string}
diff --git a/tests/testdata/not_a_processing_script.py b/tests/testdata/not_a_processing_script.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+
+print('a')
+
diff --git a/tests/testdata/script_with_error.py b/tests/testdata/script_with_error.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+
+if 1==:
+