Add QgsPathResolver::setPathWriter and QgsPathResolver::removePathWriter

qgis · Jun 18, 2021 · c09be93 · c09be93
1 parent e205ce8
commit c09be93
Show file tree

Hide file tree

Showing 4 changed files with 242 additions and 1 deletion.
diff --git a/python/core/auto_generated/qgspathresolver.sip.in b/python/core/auto_generated/qgspathresolver.sip.in
@@ -137,6 +137,79 @@ The ``id`` must correspond to a pre-processor previously added via a call to :py
     }
 %End
 
+
+
+
+    static QString setPathWriter( SIP_PYCALLABLE / AllowNone / );
+%Docstring
+Sets a path writer function, which allows for manipulation of paths and data sources prior
+to writing them to the project file.
+
+The ``writer`` function must accept a single string argument (representing the original file path
+or data source), and return a processed version of this path.
+
+The path writer function is called before any bad layer handler.
+
+If multiple writers are set, they will be called in sequence based on the order in which
+they were originally set.
+
+Example - replace path with a variable:
+
+.. code-block:: python
+
+       def my_processor(path):
+          return path.replace('c:/Users/ClintBarton/Documents/Projects', '@projectdir@')
+
+       QgsPathResolver.setPathWriter(my_processor)
+
+.. versionadded:: 3.22
+%End
+%MethodCode
+    PyObject *s = 0;
+    Py_BEGIN_ALLOW_THREADS
+    Py_XINCREF( a0 );
+    QString id = QgsPathResolver::setPathWriter( [a0]( const QString &arg )->QString
+    {
+      QString res;
+      SIP_BLOCK_THREADS
+      PyObject *s = sipCallMethod( NULL, a0, "D", &arg, sipType_QString, NULL );
+      int state;
+      int sipIsError = 0;
+      QString *t1 = reinterpret_cast<QString *>( sipConvertToType( s, sipType_QString, 0, SIP_NOT_NONE, &state, &sipIsError ) );
+      if ( sipIsError == 0 )
+      {
+        res = QString( *t1 );
+      }
+      sipReleaseType( t1, sipType_QString, state );
+      SIP_UNBLOCK_THREADS
+      return res;
+    } );
+
+    s = sipConvertFromNewType( new QString( id ), sipType_QString, 0 );
+    Py_END_ALLOW_THREADS
+    return s;
+%End
+
+
+    static void removePathWriter( const QString &id );
+%Docstring
+Removes the custom writer function with matching ``id``.
+
+The ``id`` must correspond to a writer previously added via a call to :py:func:`~QgsPathResolver.setPathWriter`.
+An KeyError will be raised if no processor with the specified ``id`` exists.
+
+.. seealso:: :py:func:`setPathWriter`
+
+.. versionadded:: 3.22
+%End
+%MethodCode
+    if ( !QgsPathResolver::removePathWriter( *a0 ) )
+    {
+      PyErr_SetString( PyExc_KeyError, QStringLiteral( "No writer with id %1 exists." ).arg( *a0 ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+%End
+
 };
 
 /************************************************************************

diff --git a/src/core/qgspathresolver.cpp b/src/core/qgspathresolver.cpp
@@ -25,6 +25,7 @@
 
 typedef std::vector< std::pair< QString, std::function< QString( const QString & ) > > > CustomResolvers;
 Q_GLOBAL_STATIC( CustomResolvers, sCustomResolvers )
+Q_GLOBAL_STATIC( CustomResolvers, sCustomWriters )
 
 QgsPathResolver::QgsPathResolver( const QString &baseFileName )
   : mBaseFileName( baseFileName )
@@ -189,8 +190,26 @@ bool QgsPathResolver::removePathPreprocessor( const QString &id )
   return prevCount != sCustomResolvers()->size();
 }
 
-QString QgsPathResolver::writePath( const QString &src ) const
+QString QgsPathResolver::setPathWriter( const std::function<QString( const QString & )> &writer )
 {
+  QString id = QUuid::createUuid().toString();
+  sCustomWriters()->emplace_back( std::make_pair( id, writer ) );
+  return id;
+}
+
+bool QgsPathResolver::removePathWriter( const QString &id )
+{
+  const size_t prevCount = sCustomWriters->size();
+  sCustomWriters()->erase( std::remove_if( sCustomWriters->begin(), sCustomWriters->end(), [id]( std::pair< QString, std::function< QString( const QString & ) > > &a )
+  {
+    return a.first == id;
+  } ), sCustomWriters->end() );
+  return prevCount != sCustomWriters->size();
+}
+
+QString QgsPathResolver::writePath( const QString &s ) const
+{
+  QString src = s;
   if ( src.isEmpty() )
   {
     return src;
@@ -200,6 +219,10 @@ QString QgsPathResolver::writePath( const QString &src ) const
   if ( !localizedPath.isEmpty() )
     return QStringLiteral( "localized:" ) + localizedPath;
 
+  const CustomResolvers customWriters = *sCustomWriters();
+  for ( const auto &writer :  customWriters )
+    src = writer.second( src );
+
   if ( src.startsWith( QgsApplication::pkgDataPath() + QStringLiteral( "/resources" ) ) )
   {
     // replace inbuilt data folder path with "inbuilt:" prefix

diff --git a/src/core/qgspathresolver.h b/src/core/qgspathresolver.h
@@ -172,6 +172,114 @@ class CORE_EXPORT QgsPathResolver
     % End
 #endif
 
+
+
+    /**
+     * Sets a path writer function, which allows for manipulation of paths and data sources prior
+     * to writing them to the project file.
+     *
+     * The \a writer function must accept a single string argument (representing the original file path
+     * or data source), and return a processed version of this path.
+     *
+     * The path writer function is called before any bad layer handler.
+     *
+     * If multiple writers are set, they will be called in sequence based on the order in which
+     * they were originally set.
+     *
+     * \returns An auto-generated string uniquely identifying the writer, which can later be
+     * used to remove the writer (via a call to removePathWriter()).
+     *
+     * \see removePathWriter()
+     * \since QGIS 3.22
+     */
+#ifndef SIP_RUN
+    static QString setPathWriter( const std::function< QString( const QString &filename )> &writer );
+#else
+
+    /**
+     * Sets a path writer function, which allows for manipulation of paths and data sources prior
+     * to writing them to the project file.
+     *
+     * The \a writer function must accept a single string argument (representing the original file path
+     * or data source), and return a processed version of this path.
+     *
+     * The path writer function is called before any bad layer handler.
+     *
+     * If multiple writers are set, they will be called in sequence based on the order in which
+     * they were originally set.
+     *
+     * Example - replace path with a variable:
+     *
+     * \code{.py}
+     *   def my_processor(path):
+     *      return path.replace('c:/Users/ClintBarton/Documents/Projects', '@projectdir@')
+     *
+     *   QgsPathResolver.setPathWriter(my_processor)
+     * \endcode
+     *
+     * \since QGIS 3.22
+     */
+    static QString setPathWriter( SIP_PYCALLABLE / AllowNone / );
+    % MethodCode
+    PyObject *s = 0;
+    Py_BEGIN_ALLOW_THREADS
+    Py_XINCREF( a0 );
+    QString id = QgsPathResolver::setPathWriter( [a0]( const QString &arg )->QString
+    {
+      QString res;
+      SIP_BLOCK_THREADS
+      PyObject *s = sipCallMethod( NULL, a0, "D", &arg, sipType_QString, NULL );
+      int state;
+      int sipIsError = 0;
+      QString *t1 = reinterpret_cast<QString *>( sipConvertToType( s, sipType_QString, 0, SIP_NOT_NONE, &state, &sipIsError ) );
+      if ( sipIsError == 0 )
+      {
+        res = QString( *t1 );
+      }
+      sipReleaseType( t1, sipType_QString, state );
+      SIP_UNBLOCK_THREADS
+      return res;
+    } );
+
+    s = sipConvertFromNewType( new QString( id ), sipType_QString, 0 );
+    Py_END_ALLOW_THREADS
+    return s;
+    % End
+#endif
+
+    /**
+     * Removes the custom writer function with matching \a id.
+     *
+     * The \a id must correspond to a writer previously added via a call to setPathWriter().
+     *
+     * Returns TRUE if writer existed and was removed.
+     *
+     * \see setPathWriter()
+     * \since QGIS 3.22
+     */
+#ifndef SIP_RUN
+    static bool removePathWriter( const QString &id );
+#else
+
+    /**
+     * Removes the custom writer function with matching \a id.
+     *
+     * The \a id must correspond to a writer previously added via a call to setPathWriter().
+     * An KeyError will be raised if no processor with the specified \a id exists.
+     *
+     * \see setPathWriter()
+     * \since QGIS 3.22
+     */
+    static void removePathWriter( const QString &id );
+    % MethodCode
+    if ( !QgsPathResolver::removePathWriter( *a0 ) )
+    {
+      PyErr_SetString( PyExc_KeyError, QStringLiteral( "No writer with id %1 exists." ).arg( *a0 ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    % End
+#endif
+
   private:
     //! path to a file that is the base for relative path resolution
     QString mBaseFileName;

diff --git a/tests/src/python/test_qgspathresolver.py b/tests/src/python/test_qgspathresolver.py
@@ -157,6 +157,43 @@ def testRelativeProject(self):
         self.assertEqual(resolver.readPath('testlayer.shp').replace("\\", "/"), os.path.join(TEST_DATA_DIR, 'qgis_server', 'testlayer.shp').replace("\\", "/"))
         os.chdir(curdir)
 
+    def __test__path_writer(self, path):
+        if path.startswith(TEST_DATA_DIR):
+            return os.path.join("@TEST_DATA_DIR@", os.path.basename(path))
+        return path
+
+    def __test_path_reader(self, path):
+        if path.startswith("@TEST_DATA_DIR@"):
+            return os.path.join(TEST_DATA_DIR, os.path.basename(path))
+        return path
+
+    def testPathWriter(self):
+        readerId = QgsPathResolver.setPathPreprocessor(self.__test_path_reader)
+        writerId = QgsPathResolver.setPathWriter(self.__test__path_writer)
+
+        lines_shp_path = os.path.join(TEST_DATA_DIR, 'lines.shp')
+
+        lines_layer = QgsVectorLayer(lines_shp_path, 'Lines', 'ogr')
+        self.assertTrue(lines_layer.isValid())
+        p = QgsProject()
+        p.addMapLayer(lines_layer)
+        # save project to a temporary file
+        temp_path = tempfile.mkdtemp()
+        temp_project_path = os.path.join(temp_path, 'temp.qgs')
+        self.assertTrue(p.write(temp_project_path))
+
+        with open(temp_project_path) as f:
+            self.assertTrue("@TEST_DATA_DIR@" in f.read())
+
+        p2 = QgsProject()
+        self.assertTrue(p2.read(temp_project_path))
+        l = p2.mapLayersByName('Lines')[0]
+        self.assertEqual(l.isValid(), True)
+        self.assertEqual(l.source(), lines_shp_path)
+
+        QgsPathResolver.removePathPreprocessor(readerId)
+        QgsPathResolver.removePathWriter(writerId)
+
 
 if __name__ == '__main__':
     unittest.main()