Create message drafts

MessageDraft represents an unpublished message. Use it to:

• Edit text before publishing
• Add channel references, user mentions, and links
• Attach files

Display message elements (mentions, references, links) in your UI by adding a message draft change listener.

Basics

Message drafts consist of MessageElement objects, which can be either instances of plainText or link.

plainText elements are simple strings. link elements are used for user mentions, channel references, and URLs. Each link contains text and a reference to the linked element.

Each link implements a MentionTarget interface, which defines the type of mention. Available targets include:

• MentionTarget.user(userId: String)
• MentionTarget.channel(channelId: String)
• MentionTarget.url(url: String)

Store draft messages locally

Chat SDK does not persist drafts. Implement your own local storage to save drafts across channel switches.

Class diagram

Example

Consider the message Hey, I sent Alex this link on the #offtopic channel. where:

• Alex is a reference to the user with the ID of alex_d
• link is a URL of the www.pubnub.com website
• #offtopic is a reference to the channel with the ID of group.offtopic

The list of MessageElement objects returned by the MessageDraftChangeListener is as follows:

Part of Message	Element Type	Code Used to Create
Hey, I sent	plainText	messageDraft.update(text = "Hey, I sent Alex this link on the #offtopic channel.")
Alex	link	messageDraft.addMention(offset = 12, length = 4, target = MentionTarget.User(userId = "alex_d"))
this	plainText	messageDraft.update(text = "Hey, I sent Alex this link on the #offtopic channel.")
link	link	messageDraft.addMention(offset = 22, length = 4, target = MentionTarget.Url(url = "www.pubnub.com"))
on the	plainText	messageDraft.update(text = "Hey, I sent Alex this link on the #offtopic channel.")
#offtopic	link	messageDraft.addMention(offset = 34, length = 9, target = MentionTarget.Channel(channelId = "group.offtopic"))
channel.	plainText	messageDraft.update(text = "Hey, I sent Alex this link on the #offtopic channel.")

Internal mention format

By internally leveraging a Markdown-like syntax, the message draft format integrates links directly into the message text using the pattern [link text](link target) understood by the Swift Chat SDK.

Mention Type	Example
user	[John Doe](pn-user://john_doe)
channel	[General Chat](pn-channel://group.chat.123)
url	[PubNub](https://www.pubnub.com)

Custom schemas like pn-user:// and pn-channel:// are used to identify user and channel mentions, while traditional URLs are supported as-is.

Adding message elements

You don't use this Markdown-like syntax when adding message elements. It's only a representation of your message elements under the hood.

For more information, refer to Add message element.

Create a draft message

createMessageDraft() creates a message draft (MessageDraft object) that can consist of:

• Plain text
• Files
• Mentioned users
• Referenced channels
• Links

Method signature

This method has the following signature:

1channel.createMessageDraft(
2  userSuggestionSource: UserSuggestionSource = .channel,
3  isTypingIndicatorTriggered: Bool = true,
4  userLimit: Int = 10,
5  channelLimit: Int = 10
6) -> MessageDraftImpl

Input

* required

Parameter	Description
userSuggestionSource Type: UserSuggestionSource = .channel or UserSuggestionSource = .global Default: UserSuggestionSource = .channel	This parameter refers to the Mentions feature. Data source from which you want to retrieve users. You can choose either the list of channel members (.channel) or users on the app's Admin Portal keyset (.global).
isTypingIndicatorTriggered Type: Bool Default: true	This parameter refers to the Typing Indicator feature. Defines if the typing indicator should be enabled when writing the message.
userLimit Type: Int Default: 10	This parameter refers to the Mentions feature. Maximum number of usernames (name field from the User object) you can mention in one message. The default value is 10, the min is 1, and max is 100.
channelLimit Type: Int Default: 10	This parameter refers to the References feature. Maximum number of channel names (name field from the Channel object) you can reference in one message. The default value is 10, the min is 1, and max is 100.

Output

Parameter	Description
MessageDraftType	Instance of MessageDraftType, which represents a draft version of a message with the content, all links, referenced channels, mentioned users and their names.

Sample code

Create a draft message containing just plain text.

1

Create a thread message draft

createThreadMessageDraft() creates a MessageDraft for composing a reply inside a message thread. Call it on a Message or ThreadMessage object. The resulting draft targets the message's thread channel and supports the same features as a regular draft: mentions, channel references, links, and file attachments.

Method signature

This method has the following signature:

1message.createThreadMessageDraft(
2  userSuggestionSource: UserSuggestionSource = .channel,
3  isTypingIndicatorTriggered: Bool = true,
4  userLimit: Int = 10,
5  channelLimit: Int = 10
6) -> MessageDraftImpl

Input

* required

Parameter	Description
userSuggestionSource Type: UserSuggestionSource = .channel or UserSuggestionSource = .global Default: UserSuggestionSource = .channel	Data source from which you want to retrieve users for mention suggestions. Choose either the list of channel members (.channel) or all users on your Admin Portal keyset (.global).
isTypingIndicatorTriggered Type: Bool Default: true	Defines if the typing indicator should be enabled while writing the message.
userLimit Type: Int Default: 10	Maximum number of usernames (name field from the User object) you can mention in one message. The default value is 10, the min is 1, and max is 100.
channelLimit Type: Int Default: 10	Maximum number of channel names (name field from the Channel object) you can reference in one message. The default value is 10, the min is 1, and max is 100.

Output

Parameter	Description
MessageDraftType	Instance of MessageDraftType targeting the message's thread channel.

Sample code

Create a draft reply for a thread started by an existing message, then send it.

1

Add message draft change listener

Add a MessageDraftChangeListener to receive draft content changes and suggestions for mentions, channel references, and links.

Method signature

This method has the following signature:

1messageDraft.addChangeListener(_ listener: MessageDraftChangeListener)
2

3public protocol MessageDraftChangeListener: AnyObject {
4  /// Called when there is a change in the message elements or suggested mentions.
5  func onChange(messageElements: [MessageElement], suggestedMentions: any FutureObject<[SuggestedMention]>)
6}

Input

Parameter	Description
_ listener Type: MessageDraftChangeListener	The listener that receives the most current message elements and suggestions list.

MessageDraftChangeListener

Parameter

Description

onChange(messageElements: [MessageElement], suggestedMentions: any FutureObject<[SuggestedMention]>) Type: function

messageElements: [MessageElement] - this parameter is a list of MessageElement objects, representing the current state of the message draft. This could contain a mix of plain text and links, channel references, or user mentions. suggestedMentions: any FutureObject<[SuggestedMention]> - this parameter is a FutureObject containing a list of SuggestedMention objects. These are potential suggestions for message elements based on the current text in the draft.

SuggestedMention

A SuggestedMention represents a potential mention suggestion received from MessageDraftChangeListener.

Parameter	Description
offset Type: Int	The position from the start of the message draft where the message elements starts. It's counted from the beginning of the message (including spaces), with 0 as the first character.
replaceFrom Type: String	The original text at the given offset in the message draft text.
replaceWith Type: String	The suggested replacement for the replaceFrom text.
target Type: MentionTarget	The message element type. Available types include: MentionTarget.user(userId: String) MentionTarget.channel(channelId: String) MentionTarget.url(url: String)

Output

This method doesn't return any data.

Sample code

Add the listener to your message draft.

1

Remove message draft change listener

Remove a previously added MessageDraftChangeListener.

Method signature

This method has the following signature:

1messageDraft.removeChangeListener(_ listener: MessageDraftChangeListener)

Input

Parameter	Description
_ listener Type: MessageDraftChangeListener	The listener to remove.

Output

This method doesn't return any data.

Sample code

Remove a listener from your message draft.

1

Add message element

addMention() adds a user mention, channel reference or a link specified by a mention target at a given offset.

Method signature

This method has the following signature:

1messageDraft.addMention(
2  offset: Int, 
3  length: Int, 
4  target: MentionTarget
5)

Input

* required

Parameter	Description
offset * Type: Int Default: n/a	Position of a character in a message where the message element you want to insert starts. It's counted from the beginning of the message (including spaces), with 0 as the first character.
length * Type: Int Default: n/a	Number of characters the message element should occupy in the draft message's text.
target * Type: MentionTarget Default: n/a	Message element type. Available types include: MentionTarget.user(userId: String) MentionTarget.channel(channelId: String) MentionTarget.url(url: String)

Output

This method returns no output data.

Sample code

Create the Hello Alex! I have sent you this link on the #offtopic channel. message where Alex is a user mention, link is a URL, and #offtopic is a channel reference.

1

Remove message element

removeMention() removes a user mention, channel reference, or a link at a given offset.

Method signature

This method has the following signature:

1messageDraft.removeMention(offset: Int)

Input

* required

Parameter	Description
offset * Type: Int Default: n/a	Position of the first character of the message element you want to remove.

Offset value

If you don't provide the position of the first character of the message element to remove, it isn't removed.

Output

This method returns no output data.

Sample code

Remove the URL element from the word link in the Hello Alex! I have sent you this link on the #offtopic channel. message.

1

Update message text

update() replaces the text of a draft message with new content.

Removing message elements

The SDK preserves message elements when possible. If element text is modified, that element is removed.

Method signature

This method has the following signature:

1messageDraft.update(text: String)

Input

* required

Parameter	Description
text * Type: string Default: n/a	Text of the message that you want to update.

Output

This method returns no output data.

Sample code

Change the message I sent Alex this picture. to I did not send Alex this picture. where Alex is a user mention.

1

Mention text changes

Changing mention text removes that mention. For finer control, use Insert message text and Remove message text.

Insert suggested message element

Insert a message element from the MessageDraftChangeListener into the MessageDraft object.

Text must match

SuggestedMention.replaceFrom must match the draft text at the specified position, or an exception is thrown.

Method signature

This method has the following signature:

1messageDraft.insertSuggestedMention(
2  mention: SuggestedMention, 
3  text: String
4)

Input

* required

Parameter	Description
mention * Type: SuggestedMention Default: n/a	A user, channel, or URL suggestion obtained from MessageDraftChangeListener.
text * Type: string Default: n/a	The text you want the message element to display.

Output

This method returns no output data.

Sample code

Register a listener and insert a suggested element.

1

Insert message text

insertText() inserts plain text in the draft message at the specified offset.

Removing message elements

Inserting text at an existing message element position removes that element.

Method signature

This method has the following signature:

1messageDraft.insertText(
2    offset: Int, 
3    text: String
4)

Input

* required

Parameter	Description
offset * Type: Int Default: n/a	Position of a character in a message where the text you want to insert starts. It's counted from the beginning of the message (including spaces), with 0 as the first character.
text * Type: string Default: n/a	Text that you want to insert.

Output

This method returns no output data.

Sample code

In the message Check this support article https://www.support-article.com/., add the word out between the words Check and this.

1

Remove message text

removeText() removes plain text from the draft message at the specified offset.

Removing message elements

Removing text at an existing message element position removes that element.

Method signature

This method has the following signature:

1messageDraft.removeText(
2    offset: Int, 
3    length: Int
4)

Input

* required

Parameter	Description
offset * Type: Int Default: n/a	Position of a character in a message where the text you want to insert starts. It's counted from the beginning of the message (including spaces), with 0 as the first character.
length * Type: Int Default: n/a	How many characters to remove, starting at the given offset.

Output

This method returns no output data.

Sample code

In the message Check out this support article https://www.support-article.com/., remove the word out.

1

Send a draft message

send() publishes the draft message with all mentioned users, links, and referenced channels. Mentioning users also emits mention events.

Method signature

This method has the following signature:

1messageDraft.send(
2  params: SendTextParams = SendTextParams()
3) async throws -> Timetoken

The SendTextParams struct groups common publishing options:

1public struct SendTextParams {
2    public var meta: [String: JSONCodable]?
3    public var shouldStore: Bool
4    public var usePost: Bool
5    public var ttl: Int?
6    public var customPushData: [String: String]?
7}

Input

* required

Parameter	Description
params Type: SendTextParams Default: SendTextParams()	Publishing options grouped in a single struct. See sendText() for field descriptions.

Message elements (links, quotes, mentions, channel references) are not passed to send() directly. Add them to the MessageDraft object through addMention() and addQuote().

Output

Parameter	Description
Timetoken	Timetoken of the message.

Sample code

Send a draft message containing just plain text.

1