FileMonitor Manual

Table of Contents

• About
• FileMonitor
• Further Reading

About

The maxon::FileMonitor class can be used to watch a certain folder. If a file in that folder is changed, a delegate is called.

Warning

The events observed and messages sent depend on the OS.

FileMonitor

maxon::FileMonitor::WatchDirectory() is used to watch the given folder.

// This example shows how to use maxon::FileMonitor to watch a given folder.
 
// global instance of FileMonitorItemRef
maxon::FileMonitorItemRef g_directoryWatch;
 
// ------------------------------------------------------------
// This function watches the given folder.
// ------------------------------------------------------------
static maxon::Result<void> WatchFolder(const maxon::Url& url)
{
  iferr_scope;
 
  // check argument
  if (url.IoDetect() != maxon::IODETECT::DIRECTORY)
    return maxon::IllegalArgumentError(MAXON_SOURCE_LOCATION);
 
  // lambda function called when a file is was changed
  auto folderActivity = [](const maxon::Url& watched, const maxon::Url& updated, maxon::FileMonitor::STATE state)
                        {
                          DiagnosticOutput("Some change in folder @.", watched);
                        };
 
  // watch folder and store FileMonitorItemRef
  g_directoryWatch = nullptr;
  g_directoryWatch = maxon::FileMonitor::WatchDirectory(url, false, folderActivity) iferr_return;
 
  return maxon::OK;
}
 
static void ClearWatcher()
{
  // clear global instance at the end
  g_directoryWatch = nullptr;
}
 
MAXON_INITIALIZATION(nullptr, ClearWatcher);

Further Reading

• Maxon API Files & Media
• Url Manual