Messages Overview

Let’s dive right into it, the example below shows how to send a simple message using Stream:

import StreamChat

/// 1: Create a `ChannelId` that represents the channel you want to send a message to.
let channelId = ChannelId(type: .messaging, id: "general")

/// 2: Use the `ChatClient` to create a `ChatChannelController` with the `ChannelId`.
let channelController = chatClient.channelController(for: channelId)

/// 3: Call `ChatChannelController.createNewMessage` to create the message.
channelController.createNewMessage(text: "Hello") { result in
  switch result {
  case .success(let messageId):
    print(messageId)
  case .failure(let error):
    print(error)
  }
}

Note how server side SDKs require that you specify user_id to indicate who is sending the message. You can add custom fields to both the message and the attachments. There’s a 5KB limit for the custom fields. File uploads are uploaded to the CDN so don’t count towards this 5KB limit.

nametypedescriptiondefaultoptional
textstringThe text of the chat message (Stream chat supports markdown and automatically enriches URLs).
attachmentsarrayA list of attachments (audio, videos, images, and text). Max is 30 attachments per message. The total combined attachment size can’t exceed 5KB.
user_idobjectThis value is automatically set in client-side mode. You only need to send this value when using the server-side APIs.
mentioned_usersarrayA list of users mentioned in the message. You send this as a list of user IDs and receive back the full user data.
message custom dataobjectExtra data for the message. Must not exceed 5KB in size.
skip_pushbooldo not send a push notificationfalse

Complex Example

A more complex example for creating a message is shown below:

// 1: Create a `ChannelId` that represents the channel you want to send a message to.
let channelId = ChannelId(type: .messaging, id: "general")

// 2: Use the `ChatClient` to create a `ChatChannelController` with the `ChannelId`.
let channelController = chatClient.channelController(for: channelId)

// 3: Call `ChatChannelController.createNewMessage`
let fileURL = URL(filePath: "<file url>")
let attachment = try AnyAttachmentPayload(
  localFileURL: fileURL,
  attachmentType: .file
)
channelController.createNewMessage(
  text: "Hello",
  pinning: .noExpiration,
  isSilent: false,
  attachments: [attachment],
  mentionedUserIds: [],
  quotedMessageId: "quotedid",
  skipPush: false,
  skipEnrichUrl: false,
  extraData: ["priority": .bool(true)]) { result in
    // …
  }

mentioned_users field must contain a maximum of 25 items.

By default Stream’s UI components support the following attachment types:

  • Audio
  • Video
  • Image
  • Text

You can specify different types as long as you implement the frontend rendering logic to handle them. Common use cases include:

  • Embedding products (photos, descriptions, outbound links, etc.)
  • Sharing of a users location

The React tutorial for Stream Chat explains how to customize the Attachment component.

Get a Message

You can get a single message by its ID using the getMessage call:

import StreamChat

/// 1: Create a `ChannelId` that represents the channel you want to get a message from.
let channelId = ChannelId(type: .messaging, id: "general")

/// 1: Create a `MessageId` that represents the message you want to get.
let messageId = "message-id"

/// 2: Use the `ChatClient` to create a `ChatChannelController` with the `ChannelId`.
let messageController = chatClient.messageController(cid: channelId, messageId: messageId)

/// 3: Call `ChatChannelController.createNewMessage` to create the message.
messageController.synchronize { error in
  // handle possible errors / access message
  print(error ?? messageController.message!)
}

Get a Message Options

nametypedescriptiondefaultoptional
show_deleted_messagebooleanif true, returns the original messagefalse

show_deleted_message is exposed for server-side calls only.

Update a Message

You can edit a message by calling updateMessage and including a message with an ID – the ID field is required when editing a message:

messageController.editMessage(text: "Hello!!!") { error in
  // handle possible errors / access message
  print(error ?? messageController.message!)
}

Partial Update

A partial update can be used to set and unset specific fields when it is necessary to retain additional data fields on the object. AKA a patch style update.

let originalMessage = (
  await channel.sendMessage({
    text: "this message is about to be partially updated",
    color: "red",
    details: {
      status: "pending",
    },
  })
).message;

// partial update message text
const text = "the text was partial updated";
const updated = await client.partialUpdateMessage(originalMessage.id, {
  set: {
    text,
  },
});

// unset color property
const updated = await client.partialUpdateMessage(originalMessage.id, {
  unset: ["color"],
});

// set nested property
const updated = await client.partialUpdateMessage(originalMessage.id, {
  set: {
    "details.status": "complete",
  },
});

Delete A Message

You can delete a message by calling deleteMessage and including a message with an ID. Messages can be soft deleted or hard deleted. Unless specified via the hard parameter, messages are soft deleted. Be aware that deleting a message doesn’t delete its attachments. See the docs for more information on deleting attachments.

messageController.deleteMessage { error in
  // handle possible errors
  print(error ?? "success")
}

Soft delete

  1. Can be done client-side by users

  2. Message is still returned in the message list and all its data is kept as it is

  3. Message type is set to “deleted”

  4. Reactions and replies are kept in place

  5. Can be undeleted

Hard delete

  1. Can be done client-side by users but be cautious this action is not recoverable

  2. The message is removed from the channel and its data is wiped

  3. All reactions are deleted

  4. All replies and their reactions are deleted

By default messages are soft deleted, this is a great way to keep the channel history consistent.

Undelete a message

A message that was soft-deleted can be undeleted. This is only allowed for server-side clients. The userID specifies the user that undeleted the message, which can be used for auditing purposes.

Messages can be undeleted if:

  • The message was soft-deleted

  • The channel has not been deleted

  • It is not a reply to a deleted message. If it is, the parent must be undeleted first

  • The user that undeletes the message is valid

await client.undeleteMessage(messageID, userID);
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