Send files

Attach files to messages to share information or improve collaboration.

Chat SDK supports multiple file attachments per message (unlike the JavaScript SDK). Each file must be 5 MB or less. Files upload sequentially, so consider implementing a progress indicator for better UX.

Requires File Sharing

Enable File Sharing in the Admin Portal and configure storage region and retention. Align file retention with Message Persistence retention.

Send files

Attach files to a draft message and publish using send().

Method signature

To add files, you must add elements to the files field (MutableList<InputFile>) of a MessageDraft object.

Sample code

Attach two files of different formats to a text message.

1// create a draft message
2val messageDraft = channel.createMessageDraft(isTypingIndicatorTriggered = channel.type != ChannelType.PUBLIC)
3

4// add a listener
5val listener = { elements: List<MessageElement>, suggestedMentions: PNFuture<List<SuggestedMention>> ->
6        updateUI(elements) // updateUI is your own function for updating UI
7        suggestedMentions.async { result ->
8            result.onSuccess { updateSuggestions(it) } // updateSuggestions is your own function for displaying suggestions
9        }
10    }
11messageDraft.addChangeListener(listener)
12

13// work on editing message with messageDraft.update(text)
14

15// attach files
16messageDraft.files.add(
17    InputFile("filename.txt", "text/plain", FileInputStream("filename.txt")))
18messageDraft.files.add(
19    InputFile("document.pdf", "application/pdf", FileInputStream("/path/to/document.pdf")))
20

21messageDraft.send()

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Get all message files

files returns all files attached to a message.

Field signature

This field has the following signature:

1val files: List<File>

Sample code

List all files attached to the last message on the support channel.

1val channel: Channel
2// ...
3

4// get the last message from the channel’s history
5channel.getHistory(count = 1).async { historyResult ->
6    historyResult.onSuccess { historyResponse ->
7        val lastMessage = historyResponse.messages.firstOrNull()
8        if (lastMessage != null) {
9            // access the files property of the last message
10            val files = lastMessage.files
11

12            if (files.isNotEmpty()) {
13                println("The last message contains the following files:")
14                files.forEach { file ->
15                    println("File Name: ${file.name}, File Type: ${file.type}")
16                }
17            } else {
18                println("The last message does not contain any files.")
19            }
20        } else {
21            println("No messages found in the support channel.")
22        }
23    }.onFailure {
24        println("Error getting history for the support channel: ${it.message}")
25        it.printStackTrace()
26    }
27}

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Get all channel files

getFiles() returns all files attached to messages on a channel.

Method signature

This method takes the following parameters:

1channel.getFiles(
2    limit: Int?,
3    next: String? 
4): PNFuture<GetFilesResult>

Input

* required

Parameter	Description
limit Type: Int Default: 100	Number of files to return.
next Type: String Default: n/a	String token to get the next batch of files.

Output

Parameter	Description
PNFuture<GetFilesResult> Type: object	Returned object containing these fields: files, next, and total.
→ files Type: Collection<GetFileItem>	Array containing file details.
→ next Type: String	Random string returned from the server, indicating a specific position in a data set. Used for forward pagination, it fetches the next page, allowing you to continue from where you left off.
→ total Type: Int	Total number of files.

GetFileItem contains the following properties:

Parameter	Description
name Type: String	Name of the file, like error-1.jpg.
id Type: String	Unique identifier assigned to the file by PubNub, like 736499374.
url Type: String	File's direct downloadable URL, like https://ps.pndsn.com/v1/files/demo/channels/support/files/736499374/error-1.jpg.

Sample code

List all files published on the support channel.

1val channel: Channel
2

3fun fetchFiles(channel: Channel, next: String?) {
4    channel.getFiles(limit = 100, next = next).async { result ->
5        result.onSuccess { filesResult ->
6            filesResult.files.forEach { file ->
7                println("File name: ${file.name}, File URL: ${file.url}")
8            }
9

10            // Check if there is another page of results
11            if (filesResult.next != null) {
12                fetchFiles(channel, filesResult.next)
13            }
14        }.onFailure {
15            // handle error
16            println("Error retrieving files: ${it.message}")
17        }
18    }
19}
20

21// ...
22

23fetchFiles(channel, null)

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Delete files

deleteFile() removes files from PubNub storage.

Endpoint limitation

After deleting a file, you cannot identify which historical messages contained it.

Method signature

This method takes the following parameters:

1channel.deleteFile(
2    id: String,
3    name: String
4): PNFuture<PNDeleteFileResult>

Input

* required

Parameter	Description
id * Type: String Default: n/a	Unique identifier assigned to the file by PubNub.
name * Type: String Default: n/a	Name of the file.

Output

Type	Description
PNFuture<PNDeleteFileResult>	Status code of the response.

Sample code

Remove a file named error-screenshot.png from the support channel.

1val channel: Channel
2// ...
3

4// delete the file named "error-screenshot.png" from the "support" channel
5val fileId = "file-id-to-delete" // Replace this with the actual file ID
6val fileName = "error-screenshot.png"
7

8channel.deleteFile(fileId, fileName).async { result ->
9    result.onSuccess {
10        println("File '$fileName' successfully deleted from 'support' channel.")
11    }.onFailure {
12        // handle error
13        println("Error deleting file '$fileName': ${it.message}")
14    }
15}