[processing] Fix file download algorithm's temporary file missing pro…

…per extension
qgis · Jan 17, 2021 · ab0eba2 · ab0eba2
1 parent 41ffc4c
commit ab0eba2
Show file tree

Hide file tree

Showing 5 changed files with 56 additions and 2 deletions.
diff --git a/python/core/auto_generated/network/qgsfiledownloader.sip.in b/python/core/auto_generated/network/qgsfiledownloader.sip.in
@@ -38,7 +38,7 @@ An optional authentication configuration can be specified.
 %Docstring
 QgsFileDownloader
 
-:param url: the download url
+:param url: the download URL
 :param outputFileName: file name where the downloaded content will be stored
 :param authcfg: optionally apply this authentication configuration
 :param delayStart: if ``True``, the download will not be commenced immediately and must
@@ -47,6 +47,13 @@ QgsFileDownloader
                    signals before these connections have been made.
 %End
 
+    const QUrl downloadedUrl() const;
+%Docstring
+Returns the downloaded URL, which can differ from the original URL if redirects occurred.
+
+.. versionadded:: 3.18
+%End
+
   signals:
     void downloadCompleted();
 %Docstring

diff --git a/src/analysis/processing/qgsalgorithmfiledownloader.cpp b/src/analysis/processing/qgsalgorithmfiledownloader.cpp
@@ -93,6 +93,21 @@ QVariantMap QgsFileDownloaderAlgorithm::processAlgorithm( const QVariantMap &par
   if ( !feedback->isCanceled() && !exists )
     throw QgsProcessingException( tr( "Output file doesn't exist." ) );
 
+  if ( outputFile.startsWith( QgsProcessingUtils::tempFolder() ) )
+  {
+    // the output is temporary and its file name automatically generated, try to add a file extension
+    const QString downloadedUrl = downloader->downloadedUrl().toDisplayString();
+    const int length = downloadedUrl.size();
+    const int lastDotIndex = downloadedUrl.lastIndexOf( "." );
+    const int lastSlashIndex = downloadedUrl.lastIndexOf( "/" );
+    if ( lastDotIndex > -1 && lastDotIndex > lastSlashIndex && length - lastDotIndex <= 6 )
+    {
+      QFile tmpFile( outputFile );
+      tmpFile.rename( tmpFile.fileName() + downloadedUrl.mid( lastDotIndex ) );
+      outputFile += downloadedUrl.mid( lastDotIndex );
+    }
+  }
+
   QVariantMap outputs;
   outputs.insert( QStringLiteral( "OUTPUT" ), exists ? outputFile : QString() );
   return outputs;

diff --git a/src/core/network/qgsfiledownloader.cpp b/src/core/network/qgsfiledownloader.cpp
@@ -45,6 +45,10 @@ QgsFileDownloader::~QgsFileDownloader()
   }
 }
 
+const QUrl QgsFileDownloader::downloadedUrl() const
+{
+  return mReply ? mReply->url() : QUrl();
+}
 
 void QgsFileDownloader::startDownload()
 {

diff --git a/src/core/network/qgsfiledownloader.h b/src/core/network/qgsfiledownloader.h
@@ -47,7 +47,7 @@ class CORE_EXPORT QgsFileDownloader : public QObject
 
     /**
      * QgsFileDownloader
-     * \param url the download url
+     * \param url the download URL
      * \param outputFileName file name where the downloaded content will be stored
      * \param authcfg optionally apply this authentication configuration
      * \param delayStart if TRUE, the download will not be commenced immediately and must
@@ -57,6 +57,12 @@ class CORE_EXPORT QgsFileDownloader : public QObject
      */
     QgsFileDownloader( const QUrl &url, const QString &outputFileName, const QString &authcfg = QString(), bool delayStart = false );
 
+    /**
+     * Returns the downloaded URL, which can differ from the original URL if redirects occurred.
+     * \since QGIS 3.18
+     */
+    const QUrl downloadedUrl() const;
+
   signals:
     //! Emitted when the download has completed successfully
     void downloadCompleted();

diff --git a/tests/src/analysis/testqgsprocessingalgs.cpp b/tests/src/analysis/testqgsprocessingalgs.cpp
@@ -176,6 +176,8 @@ class TestQgsProcessingAlgs: public QObject
     void exportMeshCrossSection();
     void exportMeshTimeSeries();
 
+    void fileDownloader();
+
   private:
 
     bool imageCheck( const QString &testName, const QString &renderedImage );
@@ -6466,6 +6468,26 @@ void TestQgsProcessingAlgs::exportMeshCrossSection()
   QVERIFY( i == expectedLines.count() );
 }
 
+void TestQgsProcessingAlgs::fileDownloader()
+{
+  std::unique_ptr< QgsProcessingAlgorithm > alg( QgsApplication::processingRegistry()->createAlgorithmById( QStringLiteral( "native:filedownloader" ) ) );
+  QVERIFY( alg != nullptr );
+
+  QVariantMap parameters;
+  parameters.insert( QStringLiteral( "URL" ), QStringLiteral( "https://version.qgis.org/version.txt" ) );
+  parameters.insert( QStringLiteral( "OUTPUT" ), QgsProcessing::TEMPORARY_OUTPUT );
+
+  std::unique_ptr< QgsProcessingContext > context = qgis::make_unique< QgsProcessingContext >();
+  QgsProcessingFeedback feedback;
+  QVariantMap results;
+  bool ok = false;
+
+  results = alg->run( parameters, *context, &feedback, &ok );
+  QVERIFY( ok );
+  // verify that temporary outputs have the URL file extension appended
+  QVERIFY( results.value( QStringLiteral( "OUTPUT" ) ).toString().endsWith( QStringLiteral( ".txt" ) ) );
+}
+
 void TestQgsProcessingAlgs::exportMeshTimeSeries()
 {
   std::unique_ptr< QgsProcessingAlgorithm > alg( QgsApplication::processingRegistry()->createAlgorithmById( QStringLiteral( "native:meshexporttimeseries" ) ) );