Minimum LabVIEW version required is 2016

The “FileHandler” class writes every log entry to disk, but holds the log file open and executes a “Flush” command only with a minimum rate of 5 seconds (default) and only with a new log entry. This behavior was implemented to improve the performance when a lot of log entries occur very fast. You can configure the flush timeout by providing a time in seconds to the Flush Timeout (5 s) terminal of the “Create FileHandler” method. With a value of 0 (zero), the “FileHandler” directly flushes every log entry.

Version 2 of the HSE Logger introduces Create methods for the log handlers. These wrap the now-private Init methods. This is due to our efforts towards standardising on „constructors“ for our classes in LabVIEW.

To upgrade an existing project from v1.x to v2.x, the Init method needs to be replaced with the Create method (the class constant is obsolete, too):

With version 2.1.2 we swapped the Name and Level input terminals of the Create UserEventHandler method to align it with the other Handler classes. Unfortunately, this introduces a breaking change in the HSE Logger API and breaks existent code that use the UserEventHandler class. Luckily, all you have to do is to switch the “Name” and “Level” wires for the Create UserEventHandler method (see example below).

⤋ Fix the broken code by switching the input wires. ⤋

With v2.1.0 we introduced the Formatter classes to give the developer an easy tool to affect how Handler classes format their string output. But as so often in software development, we made a few mistakes in the first version and fixed them with version 2.1.2. One of these mistakes was to give the Handler base class (Handler.lvclass) a Formatter property and Set/Get Formatter methods, despite the fact that there are Handler classes which have no usage for a Formatter object (like the UserEventHandler class). In our strive for clean code, we decided to remove the Formatter object and related methods from the base class and include them only in classes that actually can use them (e.g. FileHandler).

A second issue in version 2.1.0 was, that the “Handler Create” methods had no Formatter input terminal. This led to the fact that one has to use the Set Formatter method to set a custom Formatter object for a Handler. With the update to version 2.1.2 we moved the Setter/Getter methods and LabVIEW can't find the Set Formatter method anymore, the code is broken. To fix this for the FileHandler class, you have to relink the missing VI with the FileHandler.lvclass:Set Formatter.vi method. For the UserEventHandler class, you have to remove the Set Formatter method from the block diagram because the class no longer has a Formatter property (makes no sense for this class).

The recommended way to use Formatter objects with Handlers from version 2.1.2 onwards is to use the Formatter input terminal in the respective “Create Handler” methods. Only “Create” methods from Handler classes which support Formatters have this input terminal. See the Logging with Helper-VIs.vi example.