See also: Discord.Addons.Linking
An extension for Discord.Net that provides classes to filter and collect messages.
To initialize a new MessageCollector, you require an instance of a Discord.WebSocket.BaseSocketClient. Any inheriting types of this class also works.
private readonly BaseSocketClient _client;
var collector = new MessageCollector(_client);It might also help to set up a default filter method that can be used as a reference for any future matches you intend to use. All of the required parameters can be omitte
B0B7
d if you wish to use a custom filter of your own, as long as the contents of your filter are stored in this method. Here is an example of a MessageCollector in applied use:
public class DummyModule : ModuleBase<SocketCommandContext>
{
private readonly MessageCollector _collector;
// The MessageCollector class can be specified as a singleton for dependency injection instead
// This is a 'hacky' way to get around that for this example
public DummyModule(DiscordSocketClient client)
{
_collector = new MessageCollector(client);
}
private bool Judge(SocketMessage message, int index)
{
return Context.User.Id == message.Author.Id && Context.Channel.Id == message.Channel.Id && message.Content == "4";
}
[Command("demo")]
public async Task DummyCommandAsync()
{
var options = new MatchOptions
{
Timeout = TimeSpan.FromSeconds(10),
ResetTimeoutOnAttempt = false
};
IUserMessage message = await Context.Channel.SendMessageAsync("What is 2+2?");
MessageMatch match = await _collector.MatchAsync(Judge, options);
// If the match is null, this means that the collector failed to receive any matches within the specified time limit
if (match == null)
{
await message.ModifyAsync(m => m.Content = "No response was given. The answer was 4.");
}
else
{
await message.ModifyAsync(m => m.Content = "Correct! You get a gold star in my book.");
}
}
}There are three methods that can be used in a MessageCollector:
MessageCollector.MatchAsync(FilterDelegate, MatchOptions): Attempt to find a single message that matches the specified filterMessageCollector.CollectAsync(FilterCollectionDelegate, CollectionOptions): Attempt to collect all messages that match the specified filterMessageCollector.RunSessionAsync(MessageSession, FilterDelegate, SessionOptions): Starts the specified message session
Message sessions are a useful way to handle messages in an advanced manner. These can be built in any way to give you freedom on how a session should be handled. Here is an example of a simple message session:
public class DummySession : MessageSession
{
public DummySession(SocketCommandContext context)
{
Context = context;
Attempts = 0;
}
private SocketCommandContext Context { get; }
private int Attempts { get; set; }
private IUserMessage MessageReference { get; set; }
public override async Task OnStartAsync()
{
MessageReference = await Context.Channel.SendMessageAsync("What is 2+2?");
}
public override async Task<SessionResult> OnMessageReceivedAsync(SocketMessage message)
{
if (message.Content == "4")
{
await MessageReference.ModifyAsync(delegate (MessageProperties x)
{
x.Content = "Correct!";
});
return SessionResult.Success;
}
Attempts++;
if (Attempts >= 3)
{
await MessageReference.ModifyAsync(delegate (MessageProperties x)
{
x.Content = "You ran out of attempts. The answer was 4.";
});
return SessionResult.Success;
}
}
public override async Task OnTimeoutAsync()
{
await MessageReference.ModifyAsync(delegate (MessageProperties x)
{
x.Content = "You ran out of time. The answer was 4.";
});
}
}Using this custom session, that example command from before can be tweaked:
public class DummyModule : ModuleBase<SocketCommandContext>
{
private readonly MessageCollector _collector;
public DummyModule(DiscordSocketClient client)
{
_collector = new MessageCollector(client);
}
private bool Judge(SocketMessage message, int index)
{
return Context.User.Id == message.Author.Id && Context.Channel.Id == message.Channel.Id;
}
[Command("demo")]
public async Task DummyCommandAsync()
{
var options = new MatchOptions
{
Timeout = TimeSpan.FromSeconds(5),
ResetTimeoutOnAttempt = true
};
var session = new DummySession(Context);
// The result of this method returns a TimeSpan containing the time that was elapsed for this session
// This can easily be omitted if this is undesired
TimeSpan elapsedTime = await _collector.RunSessionAsync(session, Judge, options);
}
}Discord.Net for the original logo design.