How can a bot start a thread in Slack

Question

I am trying to have my bot framework bot reply to a user by starting a thread. This way I can keep who the bot is talking to when in a channel with many people straight.

According to the slack documentation what I need to do is set the thread_ts property to the ts property sent to my bot. I have tried a few things and have been unable to accomplish this. This is the most concise example I have:

var reply = (Activity)activity;
reply = reply.CreateReply("reply");

reply.ChannelData = JObject.Parse($"{{thread_ts:'{ts}'}}");
await context.PostAsync(reply);

This is not working for me.

Answer 1

You will need to set the text in the ChannelData in order for your bot to reply in the thread. Right now you are setting it in your activity reply = reply.CreateReply("reply"); All you need to do is this:

reply.ChannelData = JObject.Parse($"{{text:'reply', thread_ts:'{ts}'}}");

here is a full working method from a dialog:

public async Task MessageReceivedAsync(IDialogContext context, IAwaitable<IMessageActivity> argument)
{
    var activity = await argument;
    var ts = activity.ChannelData?.SlackMessage?.thread_ts
             ?? activity.ChannelData?.SlackMessage?.ts
             ?? activity.ChannelData?.SlackMessage["event"].thread_ts
             ?? activity.ChannelData?.SlackMessage["event"].ts;

    var reply = (Activity)activity;
    reply = reply.CreateReply();

    reply.ChannelData = JObject.Parse($"{{text:'reply', thread_ts:'{ts}'}}");
    await context.PostAsync(reply);
}