/// <summary>
/// Called once before ProcessRecord(). Internally it calls
/// BeginProcessing() of the InternalCommand.
/// </summary>
/// <exception cref="PipelineStoppedException">
/// a terminating error occurred, or the pipeline was otherwise stopped
/// </exception>
internal virtual void DoBegin()
{
// Note that DoPrepare() and DoBegin() should NOT be combined.
// Reason: Encoding of commandline parameters happen as part
// of DoPrepare(). If they are combined, the first command's
// DoBegin() will be called before the next command's
// DoPrepare(). Since BeginProcessing() can write objects
// to the downstream commandlet, it will end up calling
// DoExecute() (from Pipe.Add()) before DoPrepare.
if (!RanBeginAlready)
{
RanBeginAlready = true;
Pipe oldErrorOutputPipe = _context.ShellFunctionErrorOutputPipe;
CommandProcessorBase oldCurrentCommandProcessor = _context.CurrentCommandProcessor;
try
{
//
// On V1 the output pipe was redirected to the command's output pipe only when it
// was already redirected. This is the original comment explaining this behaviour:
//
// NTRAID#Windows Out of Band Releases-926183-2005-12-15
// MonadTestHarness has a bad dependency on an artifact of the current implementation
// The following code only redirects the output pipe if it's already redirected
// to preserve the artifact. The test suites need to be fixed and then this
// the check can be removed and the assignment always done.
//
// However, this makes the hosting APIs behave differently than commands executed
// from the command-line host (for example, see bugs Win7:415915 and Win7:108670).
// The RedirectShellErrorOutputPipe flag is used by the V2 hosting API to force the
// redirection.
//
if (this.RedirectShellErrorOutputPipe || _context.ShellFunctionErrorOutputPipe != null)
{
_context.ShellFunctionErrorOutputPipe = this.commandRuntime.ErrorOutputPipe;
}
_context.CurrentCommandProcessor = this;
using (commandRuntime.AllowThisCommandToWrite(true))
{
using (ParameterBinderBase.bindingTracer.TraceScope(
"CALLING BeginProcessing"))
{
SetCurrentScopeToExecutionScope();
if (Context._debuggingMode > 0 && !(Command is PSScriptCmdlet))
{
Context.Debugger.CheckCommand(this.Command.MyInvocation);
}
Command.DoBeginProcessing();
}
}
}
catch (Exception e)
{
// This cmdlet threw an exception, so
// wrap it and bubble it up.
throw ManageInvocationException(e);
}
finally
{
_context.ShellFunctionErrorOutputPipe = oldErrorOutputPipe;
_context.CurrentCommandProcessor = oldCurrentCommandProcessor;
RestorePreviousScope();
}
}
}