Command Invoker
The command invoker interface abstracts and decouples the functionality of calling commands to the backend.
Two types of commands
It is important to note the difference in the underlying split between types of commands:
Pod command (used in the
<PodCommandButton>): a command that acts like a message to the pod. These commands are entirely meant as communication to the pod from the GUI.Backend command (used in the
<BackendCommandButton>): a command that triggers auxiliary backend functionality (e.g. loading procedures, stopping the server, initiating connection, etc.)
Reasoning behind this split: when developing the DH08 GUI, the initial implementation provided such one command for sending messages to the pod in the Tauri backend, which acts as simply an intermediary between the pod and the GUI. Other commands meant to change the state of the backend or trigger different functionality were implemented as separate Tauri commands.
Usage and place in the architecture
The original GUI used Tauri, and the necessity for such an interface was not apparent at first. To support Serpenta for different stacks, the actual implementation of communication to a backend was decoupled from the Serpenta UI kit logic.
Implementation in the Tauri Starter Kit
When creating the provided Tauri Starter Kit, the implementation of the command invoker is done by using the Tauri api for commands as done in the real DH08 GUI. The option to swap it out for a different implementation still exists if desired.
Reference
Below are the TSDoc comments of each method or field part of this interface.
Methods
invokeCommand<T>(...):Promise<T>;
Invoke a command given its name/identifier and an object of arguments.
Params:
commandName: the name/identifier of the command to be executed.
args: the arguments with which the command will be called. They are of the type
Record<string, unknown>because they will take an object representing the arguments we call the command with.
Type params:
T: the return type of the invoked command.
Returns: a Promise of type T—the return type of the command itself.
Example:
If we were to call a function (in an arbitrary language) that takes arguments (width: integer, height: integer, label: string) which returns an integer, we will call this invokeCommand method as: