QML API 1.3: Add support for qrc:/ import paths. Fixes #2

docs/index.rst

@@ -28,7 +28,7 @@ This section describes the QML API exposed by the *PyOtherSide* QML Plugin.
 Import Versions
 ---------------
 
-The current QML API version of PyOtherSide is 1.2. When new features are
+The current QML API version of PyOtherSide is 1.3. When new features are
 introduced, or behavior is changed, the API version will be bumped and
 documented here.
 
@@ -48,6 +48,13 @@ io.thp.pyotherside 1.2
   :func:`importModule` or :func:`call`, the signal :func:`error` is emitted
   with the exception information (filename, line, message) as ``traceback``.
 
+io.thp.pyotherside 1.3
+``````````````````````
+
+* :func:`addImportPath` now also accepts ``qrc:/`` URLs. This is useful if
+  your Python files are embedded as Qt Resources, relative to your QML files
+  (use :func:`Qt.resolvedUrl` from the QML file).
+
 QML ``Python`` Element
 ----------------------
 
@@ -60,7 +67,7 @@ To use the ``Python`` element in a QML file, you have to import the plugin using
 
 .. code-block:: javascript
 
-    import io.thp.pyotherside 1.2
+    import io.thp.pyotherside 1.3
 
 Signals
 ```````
@@ -89,13 +96,19 @@ path and then importing the module asynchronously:
 
 .. function:: addImportPath(string path)
 
-    Add a local filesystem path to Python's ``sys.path``.
+    Add a path to Python's ``sys.path``.
 
 .. versionchanged:: 1.1.0
     :func:`addImportPath` will automatically strip a leading
     ``file://`` from the path, so you can use :func:`Qt.resolvedUrl()`
     without having to manually strip the leading ``file://`` in QML.
 
+.. versionchanged:: 1.3.0
+    Starting with QML API version 1.3 (``import io.thp.pyotherside 1.3``),
+    :func:`addImportPath` now also accepts ``qrc:/`` URLs. The first time
+    a ``qrc:/`` path is added, a new import handler will be installed,
+    which will enable Python to transparently import modules from it.
+
 .. function:: importModule(string name, function callback(success) {})
 
     Import a Python module.
@@ -104,7 +117,7 @@ path and then importing the module asynchronously:
     Previously, this function didn't work correctly for importing
     modules with dots in their name. Starting with the API version 1.2
     (``import io.thp.pyotherside 1.2``), this behavior is now fixed,
-    and ``importModule('x.y.z, ...)`` behaves like ``import x.y.z``.
+    and ``importModule('x.y.z', ...)`` behaves like ``import x.y.z``.
 
 .. versionchanged:: 1.2.0
     If a JavaScript exception occurs in the callback, the :func:`error`
@@ -152,7 +165,7 @@ plugin and Python interpreter.
 .. note::
     This is not necessarily the same as the QML API version currently in use.
     The QML API version is decided by the QML import statement, so even if
-    :func:`pluginVersion`` returns 1.2.0, if the plugin has been imported as
+    :func:`pluginVersion` returns 1.2.0, if the plugin has been imported as
     ``import io.thp.pyotherside 1.0``, the API version used would be 1.0.
 
 .. versionadded:: 1.1.0
@@ -406,6 +419,12 @@ walking the whole resource tree, printing out directory names and file sizes:
     walk('/')
 
 
+Importing Python modules from Qt Resources also works starting with QML API 1.3
+using :func:`Qt.resolvedUrl` from within a QML file in Qt Resources. As an
+alternative, ``addImportPath('qrc:/')`` will add the root directory of the Qt
+Resources to Python's module search path.
+
+
 Cookbook
 ========
 
@@ -597,7 +616,7 @@ Using this function from QML is straightforward:
 .. code-block:: javascript
 
     import QtQuick 2.0
-    import io.thp.pyotherside 1.2
+    import io.thp.pyotherside 1.3
 
     Rectangle {
         color: 'black'
@@ -693,7 +712,7 @@ This module can now be imported in QML and used as ``source`` in the QML
 .. code-block:: javascript
 
     import QtQuick 2.0
-    import io.thp.pyotherside 1.2
+    import io.thp.pyotherside 1.3
 
     Image {
         id: image
@@ -784,6 +803,7 @@ Version 1.3.0 (UNRELEASED)
 --------------------------
 
 * Access to the `Qt Resource System`_ from Python (see `Qt Resource Access`_).
+* QML API 1.3: Import from Qt Resources (:func:`addImportPath` with ``qrc:/``).
 
 Version 1.2.0 (2014-02-16)
 --------------------------

examples/qrc/data/below/qrc_example_below.py

@@ -0,0 +1,6 @@
+import sys
+import pyotherside
+
+print('Hello from below!')
+print('sys.path =', sys.path)
+print('pyotherside =', pyotherside)

examples/qrc/data/qrc_example.qml

@@ -1,5 +1,5 @@
 import QtQuick 2.0
-import io.thp.pyotherside 1.2
+import io.thp.pyotherside 1.3
 
 Rectangle {
     width: 100
@@ -10,6 +10,10 @@ Rectangle {
             addImportPath(Qt.resolvedUrl('.'));
             importModule('qrc_example', function (success) {
                 console.log('module imported: ' + success);
+                addImportPath(Qt.resolvedUrl('below'));
+                importModule('qrc_example_below', function (success) {
+                    console.log('also imported: ' + success);
+                });
             });
         }
     }

examples/qrc/data/qrc_example.qrc

@@ -3,5 +3,6 @@
   <qresource>
     <file>qrc_example.qml</file>
     <file>qrc_example.py</file>
+    <file>below/qrc_example_below.py</file>
   </qresource>
 </RCC>

src/pyotherside_plugin.cpp

@@ -60,4 +60,5 @@ PyOtherSideExtensionPlugin::registerTypes(const char *uri)
     qmlRegisterType<QPython10>(uri, 1, 0, PYOTHERSIDE_QPYTHON_NAME);
     // There is no PyOtherSide 1.1 import, as it's the same as 1.0
     qmlRegisterType<QPython12>(uri, 1, 2, PYOTHERSIDE_QPYTHON_NAME);
+    qmlRegisterType<QPython13>(uri, 1, 3, PYOTHERSIDE_QPYTHON_NAME);
 }

src/qpython.cpp

@@ -83,6 +83,15 @@ QPython::addImportPath(QString path)
         path = path.mid(7);
     }
 
+    if (SINCE_API_VERSION(1, 3) && path.startsWith("qrc:")) {
+        const char *module = "pyotherside.qrc_importer";
+        QString filename = "/io/thp/pyotherside/qrc_importer.py";
+        QString errorMessage = priv->importFromQRC(module, filename);
+        if (!errorMessage.isNull()) {
+            emit error(errorMessage);
+        }
+    }
+
     QByteArray utf8bytes = path.toUtf8();
 
     PyObject *sys_path = PySys_GetObject((char*)"path");

src/qpython.h

@@ -317,4 +317,13 @@ Q_OBJECT
     }
 };
 
+class QPython13 : public QPython {
+Q_OBJECT
+public:
+    QPython13(QObject *parent=0)
+        : QPython(parent, 1, 3)
+    {
+    }
+};
+
 #endif /* PYOTHERSIDE_QPYTHON_H */

src/qpython_priv.cpp

@@ -379,3 +379,49 @@ QPythonPriv::instance()
 {
     return priv;
 }
+
+QString
+QPythonPriv::importFromQRC(const char *module, const QString &filename)
+{
+    PyObject *sys_modules = PySys_GetObject((char *)"modules");
+    if (!PyMapping_Check(sys_modules)) {
+        return QString("sys.modules is not a mapping object");
+    }
+
+    PyObject *qrc_importer = PyMapping_GetItemString(sys_modules,
+            (char *)module);
+
+    if (qrc_importer == NULL) {
+        PyErr_Clear();
+
+        QFile qrc_importer_code(":" + filename);
+        if (!qrc_importer_code.open(QIODevice::ReadOnly)) {
+            return QString("Cannot load qrc importer source");
+        }
+
+        QByteArray ba = qrc_importer_code.readAll();
+        QByteArray fn = QString("qrc:/" + filename).toUtf8();
+
+        PyObject *co = Py_CompileString(ba.constData(), fn.constData(),
+                Py_file_input);
+        if (co == NULL) {
+            QString result = QString("Cannot compile qrc importer: %1")
+                .arg(formatExc());
+            PyErr_Clear();
+            return result;
+        }
+
+        qrc_importer = PyImport_ExecCodeModule((char *)module, co);
+        if (qrc_importer == NULL) {
+            QString result = QString("Cannot exec qrc importer: %1")
+                    .arg(formatExc());
+            PyErr_Clear();
+            return result;
+        }
+        Py_XDECREF(co);
+    }
+
+    Py_XDECREF(qrc_importer);
+
+    return QString();
+}

src/qpython_priv.h

@@ -38,6 +38,8 @@ class QPythonPriv : public QObject {
         void enter();
         void leave();
 
+        QString importFromQRC(const char *module, const QString &filename);
+
         void receiveObject(PyObject *o);
         static void closing();
         static QPythonPriv *instance();

src/qrc_importer.py

@@ -0,0 +1,47 @@
+#
+# PyOtherSide: Asynchronous Python 3 Bindings for Qt 5
+# Copyright (c) 2014, Thomas Perl <m@thp.io>
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+# FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+# PERFORMANCE OF THIS SOFTWARE.
+#
+
+import sys
+import pyotherside
+
+from importlib import abc
+
+class PyOtherSideQtRCImporter(abc.MetaPathFinder, abc.SourceLoader):
+    def find_module(self, fullname, path):
+        if path is None or all(x.startswith('qrc:') for x in path):
+            if self.get_filename(fullname):
+                return self
+
+    def get_filename(self, fullname):
+        basename = fullname.replace('.', '/')
+
+        for import_path in sys.path:
+            if not import_path.startswith('qrc:'):
+                continue
+
+            for candidate in ('{}/{}.py', '{}/{}/__init__.py'):
+                filename = candidate.format(import_path, basename)
+                if pyotherside.qrc_is_file(filename[len('qrc:'):]):
+                    return filename
+
+    def get_data(self, path):
+        return pyotherside.qrc_get_file_contents(path[len('qrc:'):])
+
+    def module_repr(self, m):
+        return "<module '{}' from '{}'>".format(m.__name__, m.__file__)
+
+sys.meta_path.append(PyOtherSideQtRCImporter())

src/qrc_importer.qrc

@@ -0,0 +1,6 @@
+<!DOCTYPE RCC>
+<RCC version="1.0">
+  <qresource prefix="/io/thp/pyotherside/">
+    <file>qrc_importer.py</file>
+  </qresource>
+</RCC>

src/src.pro

@@ -28,6 +28,9 @@ HEADERS += pyotherside_plugin.h
 SOURCES += qpython_imageprovider.cpp
 HEADERS += qpython_imageprovider.h
 
+# Importer from Qt Resources
+RESOURCES += qrc_importer.qrc
+
 # Python QML Object
 SOURCES += qpython.cpp
 HEADERS += qpython.h

tests/tests.cpp

@@ -153,4 +153,8 @@ TestPyOtherSide::testEvaluate()
     // PyOtherSide API 1.2
     QPython12 py12;
     testEvaluateWith(&py12);
+
+    // PyOtherSide API 1.3
+    QPython13 py13;
+    testEvaluateWith(&py13);
 }