Changes in src/sas/qtgui/Utilities/SasviewLogger.py [4992ff2:5dba493] in sasview

File:

• src/sas/qtgui/Utilities/SasviewLogger.py (modified) (6 diffs)

src/sas/qtgui/Utilities/SasviewLogger.py

@@ -7 +7 @@
 
 class XStream(QObject):
+    """
+    Imitates, loosely, an `io.TextIOWrapper` class in order to intercept
+    messages going to stdout and stderr.
+
+    To intercept messages to stdout, use:
+
+    .. code-block:: python
+       XStream.stdout().messageWritten.mySignalHandler()
+
+    All messages to stdout will now also be emitted to your handler. Use
+    `XStream.stderr()` in the same way to intercept stderr messages.
+
+    An additional function, `XStream.write_log()`, emits a message only to the
+    messageWritten signal, and not the stdout or stderr streams. It is intended
+    for separation of log handling between console and Qt, as reflected in the
+    name.
+    """
     _stdout = None
     _stderr = None
     messageWritten = pyqtSignal(str)
+
+    _real_stream = None
 
     def flush(self):
@@ -18 +37 @@
 
     def write(self, msg):
+        """
+        'msg' is emitted in the messageWritten signal, and is also written to
+        the original stream. This means stdout/stderr messages have been
+        redirected to a custom location (e.g. in-widget), but also reach
+        console output.
+
+        :param msg: message to write
+        :return: None
+        """
+        if(not self.signalsBlocked()):
+            self.messageWritten.emit(str(msg))
+        self._real_stream.write(msg)
+
+    def write_log(self, msg):
+        """
+        'msg' is only emitted in the messageWritten signal, not in the original
+        stdout/stderr stream, for the purposes of logging. Use in, e.g. a
+        custom logging handler's emit() function.
+
+        :param msg: message to write
+        :return: None
+        """
         if(not self.signalsBlocked()):
             self.messageWritten.emit(str(msg))
@@ -23 +64 @@
     @staticmethod
     def stdout():
+        """
+        Creates imitation of sys.stdout.
+        :return: An XStream instance that interfaces exactly like sys.stdout,
+                 but, has redirection capabilities through the
+                 messageWritten(str) signal.
+        """
         if(not XStream._stdout):
             XStream._stdout = XStream()
+            XStream._stdout._real_stream = sys.stdout
             sys.stdout = XStream._stdout
         return XStream._stdout
@@ -30 +78 @@
     @staticmethod
     def stderr():
+        """
+        Creates imitation of sys.stderr.
+        :return: An XStream instance that interfaces exactly like sys.stderr,
+                 but, has redirection capabilities through the
+                 messageWritten(str) signal.
+        """
         if(not XStream._stderr):
             XStream._stderr = XStream()
+            XStream._stderr._real_stream = sys.stderr
             sys.stderr = XStream._stderr
         return XStream._stderr
 
+
 class QtHandler(logging.Handler):
     """
-    Version of logging handler
-    "emitting" the message to custom stdout()
+    Version of logging handler "emitting" the message to custom stdout()
     """
     def __init__(self):
@@ -46 +101 @@
         record = self.format(record)
         if record:
-            XStream.stdout().write('%s\n'%record)
+            XStream.stdout().write_log('%s\n'%record)
 
 
@@ -52 +107 @@
 logger = logging.getLogger()
 
-# Add the file handler
-logging.basicConfig(level=logging.INFO,
-                    format='%(asctime)s %(levelname)s %(message)s',
-                    filename=os.path.join(os.path.expanduser("~"),
-                                          'sasview.log'))
 # Add the qt-signal logger
 handler = QtHandler()
-handler.setFormatter(logging.Formatter("%(levelname)s: %(message)s"))
+handler.setFormatter(logging.Formatter(
+    fmt="%(asctime)s - %(levelname)s: %(message)s",
+    datefmt="%H:%M:%S"
+))
 logger.addHandler(handler)