Post-Execution Logic

Interaction Service uses IResult to provide information about the state of command execution. These can be used to log internal exceptions or provide some insight to the command user.

If you are running your commands using RunMode.Sync these command results can be retrieved from the return value of InteractionService.ExecuteCommandAsync method or by registering delegates to Interaction Service events.

If you are using the RunMode.Async to run your commands, you must use the Interaction Service events to get the execution results. When using RunMode.Async, InteractionService.ExecuteCommandAsync will always return a successful result.

Results

Interaction Result come in a handful of different flavours:

AutocompletionResult: returned by Autocompleters
ExecuteResult: contains the result of method body execution process
PreconditionGroupResult: returned by Precondition groups
PreconditionResult: returned by preconditions
RuntimeResult: a user implementable result for returning user defined results
SearchResult: returned by command lookup map
TypeConverterResult: returned by TypeConverters

Note

You can either use the IResult.Error property of an Interaction result or create type check for the aforementioned result types to branch out your post-execution logic to handle different situations.

CommandExecuted Events

Every time a command gets executed, Interaction Service raises a CommandExecuted event. These events can be used to create a post-execution pipeline.

interactionService.SlashCommandExecuted += SlashCommandExecuted;

async Task SlashCommandExecuted(SlashCommandInfo arg1, Discord.IInteractionContext arg2, IResult arg3)
{
    if (!arg3.IsSuccess)
    {
        switch (arg3.Error)
        {
            case InteractionCommandError.UnmetPrecondition:
                await arg2.Interaction.RespondAsync($"Unmet Precondition: {arg3.ErrorReason}");
                break;
            case InteractionCommandError.UnknownCommand:
                await arg2.Interaction.RespondAsync("Unknown command");
                break;
            case InteractionCommandError.BadArgs:
                await arg2.Interaction.RespondAsync("Invalid number or arguments");
                break;
            case InteractionCommandError.Exception:
                await arg2.Interaction.RespondAsync($"Command exception: {arg3.ErrorReason}");
                break;
            case InteractionCommandError.Unsuccessful:
                await arg2.Interaction.RespondAsync("Command could not be executed");
                break;
            default:
                break;
        }
    }
}

Log Event

InteractionService regularly outputs information about the occuring events to keep the developer informed.

Runtime Result

Interaction commands allow you to return Task<RuntimeResult> to pass on additional information about the command execution process back to your post-execution logic.

Custom RuntimeResult classes can be created by inheriting the base RuntimeResult class.