beremiz
Altered DropDown widget (#60)
* Altered DropDown widget: Added another mandatory path variable - selection value (depending on use case, one could prefer direct access to selection value rather than selection index); and another optional path variable - options (string variable to allow for dynamic change of options, as opposed to providing static list of options through arguments); and example with both static and dynamic dropdowns.
* Make second path variable optional, for backwards compatibility
* Altered DropDown widget: Added another mandatory path variable - selection value (depending on use case, one could prefer direct access to selection value rather than selection index); and another optional path variable - options (string variable to allow for dynamic change of options, as opposed to providing static list of options through arguments); and example with both static and dynamic dropdowns.
* Make second path variable optional, for backwards compatibility
* - Multiple SVGHMI instances can be configured simultaneously in the same Beremiz :doc:`../programming/configuration`, exposing different HMIs.
Each SVGHMI instance must bind to different interface-port-path triplet. In case of conflict, a build error is issued.
By default, interface is set to ``localhost``, port to ``8008`` and path is set to :doc:`../programming/configuration` Node's name: ``{name}``.
As an example, in case SVGHMI instance is first node in :doc:`../programming/configuration`, default URL to reach HMI is ``http://localhost:8008/svghmi_0``
Up to ``MaxConnections`` clients (i.e. web browser) can connect to the same SVGHMI instance simultaneously.
In case of repeated connection loss with long TCP `TTL <https://en.wikipedia.org/wiki/Time_to_live>`_, small ``MaxConnections`` number can lead to connection refusal.
When SVHGMI server doesn't receive HMI heartbeat in due time, watchdog is triggered, and ``OnWatchdog`` command is executed.
Only one single client can use watchdog at a time, and ``Watchdog`` configuration setting can be active on only one SVGHMI instance at a time.
``WatchdogInitial`` and ``WatchdogInterval`` define how long watchdog will accept to wait before receiving first heartbeat,