slack-utils

Collection of utility methods/middleware I frequently use in slackbot projects.

Disclaimer

Until major release version 1.0.0, it is safe to expect some significant changes to existing functions.

Highlighted functionality

Easy verification

Easily verify incoming requests from slash commands/interactive callbacks using the provided verification middleware.

The simplest way to enable request verification is as follows:

r := chi.NewRouter()
r.Use(utils.VerifySlashCommand(env.SigningSecret, nil, nil))
r.Use(utils.VerifyInteractionCallback(env.SigningSecret, nil, nil))

The above will verify the authenticity of all incoming requests using your signing secret and embed the verified/unmarshalled request object into the context on success. Optionally configure additional actions to be taken on success/failure (e.g. logging) by passing in corresponding callback methods.

Retrieve the request from the context and use it in the following manner:

Slash command example

func Foo(w http.ResponseWriter, r *http.Request) {
  cmd, err := utils.SlashCommand(r.Context())
  if err != nil {
    // handle error
  }

  if err = doSomething(cmd.Text); err != nil {
    // handle error
  }
}

Interactive callback example

func Callback(w http.ResponseWriter, r *http.Request) {
  callback, err := utils.InteractionCallback(r.Context())
  if err != nil {
   // handle error
  }

  switch callback.Type {
  case slack.InteractionTypeBlockActions:
    // handle block action callback
  case slack.InteractionTypeMessageAction:
    // handle message action callback
  case slack.InteractionTypeDialogSubmission:
    // handle dialog submission callback
  }
}

Posting messages and using Blocks

Below is a pseudo-code example of how to post an interactive block message to Slack using some of the utilities offered by the library

client := slack.New(env.BotToken)

startDatePickerSectionBlock := utils.NewTextBlock("Please choose a *start date* for the new survey", nil)

startDatePickerElem := utils.NewDatePickerWithOpts(startDatePickerActionID, nil, time.Now())

startDatePickerActionBlock := slack.NewActionBlock(
    startDatePickerBlockID, 
    startDatePickerElem, 
    utils.CancelBtn,
)

startDatePickerMsg = utils.Msg{
	Blocks: []slack.Block{startDatePickerSectionBlock, startDatePickerActionBlock},
}
	
_, err := utils.PostMsg(client, startDatePickerMsg, channelID)

To post ephemerally, use PostEphemeralMsg and include the target user's ID.

Delete normal/ephemeral messages alike in the following manner:

utils.DeleteMsg(client, channelID, ts, responseURL)

Working with channels

Create a new channel, invite users, and post an init message with a single command

channelHandler := &utils.Channel{
	UserClient: slack.New(env.UserToken),
	BotClient: slack.New(env.BotToken),
}
err := channelHandler.CreateChannel(channelName, userIDs, utils.Msg{Body: initMsg})

Requires UserClient with channels:write scope. Include the BotClient as well if you wish to post the init message as the bot user and not as the user associated with the UserClient token

Get all channel members' Slack IDs or emails

client := slack.New(env.BotToken)
emails, err := utils.GetChannelMemberEmails(client, env.ChannelID)

Use GetChannelMembers for Slack IDs instead of emails

Leave or archive multiple channels

channelHandler := &utils.Channel{
	UserClient: slack.New(env.UserToken),
}
err := channelHandler.LeaveChannels(channelIDs)

User ArchiveChannels to archive channels instead (both methods require UserClient with channels:write scope)

Invite multiple users to a channel

channelHandler := &utils.Channel{
	UserClient: slack.New(env.UserToken),
}
err := channelHandler.InviteUsers(userIDs)

Requires UserClient with channels:write scope

Working with users

Convert emails to Slack IDs

client := slack.New(env.BotToken)
users, err := utils.EmailsToSlackIDs(client, userEmails)

Use EmailsToSlackIDsInclusive if you want to get back both the email and the Slack ID for each user

Working with files

Read and download CSV files shared in Slack

client := slack.New(env.BotToken)
rows, err := utils.DownloadAndReadCSV(h.client, urlPrivateDownload)

Per Slack API restrictions, requires the files:read scope on the UserClient and the user associated with the token must have access to the file

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Suggestions/requests for new functionality are always welcome