File Sharing API for Go SDK

Allows users to upload and share files. You can upload any file of up to 5 MB in size. This feature is commonly used in social apps to share images, or in medical apps to share medical records for patients.

When a file is uploaded on a channel, it's stored and managed using a storage service, and associated with your key. Subscribers to that channel receive a file event which contains a file ID, filename, and optional description.

Send file

Upload the file to a specified channel.

This method covers the entire process of sending a file, including preparation, uploading the file to a cloud storage service, and post-uploading messaging on a channel.

For the last messaging step, SendFile internally calls the PublishFileMessage method to publish a message on the channel.

The published message contains metadata about the file, such as the file identifier and name, enabling others on the channel to find out about the file and access it.

Method(s)

pn.SendFile().
    Channel(string).
    Message(string).
    Name(string).
    File(*os.File).
    TTL(int).
    ShouldStore(bool).
    Meta(interface{}).
    CustomMessageType(string).    
    Execute()

* required

Parameter	Description
`Channel` * Type: string Default: n/a	Channel to upload the file.
`Message` Type: string Default: n/a	Message which should be sent along with file to specified `channel`.
`File` * Type: *os.File Default: n/a	Pointer to the File object
`TTL` Type: int Default: n/a	How long message should be stored in channel's storage.
`ShouldStore` Type: bool Default: `true`	If `true` the published file message will be stored in channel's history.
`Meta` Type: interface Default: null	Meta data object which can be used with the filtering ability
`CustomMessageType` Type: string Default: n/a	A case-sensitive, alphanumeric string from 3 to 50 characters describing the business-specific label or category of the message. Dashes `-` and underscores `_` are allowed. The value cannot start with special characters or the string `pn_` or `pn-`. Examples: `text`, `action`, `poll`.

Deprecated parameter

The CipherKey parameter in this method is deprecated. We recommend that you configure the crypto module on your PubNub instance instead.

If you pass CipherKey as an argument, it overrides the crypto module configuration and the legacy encryption with 128-bit cipher key entropy is used.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. It includes necessary imports and executes methods with console logging. Use it as a reference when working with other examples in this document.

package main

import (
	"fmt"
	"log"
	"os"

	pubnub "github.com/pubnub/go/v7"
)

func main() {
	// Configure the PubNub instance with demo keys
	config := pubnub.NewConfigWithUserId("myUniqueUserId")
	config.SubscribeKey = "demo"
	config.PublishKey = "demo"
show all 49 lines

Returns

The SendFile() operation returns a type PNSendFileResponse which contains the following properties:

Property Name	Type	Description
`Data`	PNFileData	Details of type `PNFileData` are here
`Timestamp`	int64	Returns an `int64` representation of the timetoken when the message was published.

PNFileData

PNFileData contains the following properties:

Property Name	Type	Description
`ID`	string	Returns the `ID` of the file.

List channel files

Retrieve list of files uploaded to Channel.

Method(s)

pn.ListFiles().
    Channel(string).
    Limit(int).
    Next(string).
    Execute()

* required

Parameter	Description
`Channel` * Type: string Default: n/a	`Channel` to get list of files.
`Limit` Type: int Default: 100	Number of files to return.
`Next` Type: string Default: n/a	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.

Sample code

resListFile, statusListFile, errListFile := pn.ListFiles()
    .Channel("my_channel")
    .Execute()
fmt.Println(resListFile, statusListFile, errListFile)
if resListFile != nil {
    for _, m := range resListFile.Data {
        fmt.Println(m.ID, m.Created, m.Name, m.Size)
    }
}

Returns

The ListFiles() operation returns a type PNListFilesResponse which contains the following properties:

Property Name	Type	Description
`Data`	PNFileInfo	Details of type PNFileData are here
`Count`	int	Number of files returned.
`Next`	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.

PNFileInfo

PNFileInfo contains the following properties:

Property Name	Type	Description
`Name`	string	`Name` of the file.
`Id`	string	`ID` of the file.
`Size`	int	`Size` of the file.
`Created`	string	`Created` date of the file.

Get file URL

Generate URL which can be used to download file from target Channel.

Method(s)

pn.GetFileURL().
    Channel(string).
    ID(string).
    Name(string).
    Execute()

* required

Parameter	Description
`Channel` * Type: string	Name of `channel` within which `file` with `name` has been uploaded.
`ID` * Type: string	Unique file `identifier` which has been assigned during file upload.
`Name` * Type: string	Name under which the uploaded `file` is stored for the `channel`.

Sample code

resGetFileUrl, statusGetFileUrl, errGetFileUrl := pn.GetFileURL()
    .Channel("my_channel")
    .ID("d9515cb7-48a7-41a4-9284-f4bf331bc770")
    .Name("cat_picture.jpg")
    .Execute()
fmt.Println(resGetFileUrl, statusGetFileUrl, errGetFileUrl)
fmt.Println(resGetFileUrl.URL)

Returns

The GetFileUrl() operation returns a type PNGetFileURLResponse which contains the following properties:

Property Name	Type	Description
`Url`	string	`URL` which can be used to download remote file with specified `name` and `identifier`.

Download file

Download file from specified Channel.

Method(s)

pn.DownloadFile().
    Channel(string).
    ID(string).
    Name(string).
    Execute()

* required

Parameter	Description
`Channel` * Type: string	Name of `channel` within which `file` with `name` has been uploaded.
`ID` * Type: string	Unique `file` identifier which has been assigned during `file` upload.
`Name` * Type: string	Name under which uploaded `file` is stored for `channel`.

Deprecated parameter

Sample code

resDLFile, statusDLFile, errDLFile := pn.DownloadFile()
    .Channel("my_channel")
    .ID("d9515cb7-48a7-41a4-9284-f4bf331bc770")
    .Name("cat_picture.jpg")
    .Execute()
if resDLFile != nil {
    filepathOutput := "cat_picture.jpg"
    out, _ := os.Create(filepathOutput)
    _, err := io.Copy(out, resDLFile.File)

    if err != nil {
        fmt.Println(err)
    }
}

Returns

The DownloadFile() operation returns a type PNDownloadFileResponse which contains the following properties:

Property Name	Type	Description
`File`	`io.Reader`	File Reader that can be used to save the `File`.

Delete file

Delete file from specified Channel.

Method(s)

pn.DeleteFile().
    Channel(string).
    ID(string).
    Name(string).
    Execute()

* required

Parameter	Description
`Channel` * Type: string	Name of `channel` within which `file` with `name` needs to be deleted.
`ID` * Type: string	Unique `file` identifier of the `file` to be deleted.
`Name` * Type: string	Name of the `file` to be deleted from the `channel`.

Sample code

_, statusDelFile, errDelFile := pn.DeleteFile()
    .Channel("my_channel")
    .ID("d9515cb7-48a7-41a4-9284-f4bf331bc770")
    .Name("cat_picture.jpg")
    .Execute()
fmt.Println(statusDelFile, errDelFile)

Returns

The DeleteFile() operation returns a type PNDeleteFileResponse which is nil.

Publish file message

Publish the uploaded file message to a specified channel.

This method is called internally by SendFile as part of the file-sending process to publish the message with the file (already uploaded in a storage service) on a channel.

This message includes the file's unique identifier and name elements, which are needed to construct download links and inform channel subscribers that the file is available for download.

You can call this method when SendFile fails and returns the status.operation === PNPublishFileMessageOperation error. In that case, you can use the data from the status object to try again and use PublishFileMessage to manually resend a file message to a channel without repeating the upload step.

Method(s)

pn.PublishFileMessage().
    TTL(int).
    Meta(interface{}).
    ShouldStore(bool).
    Channel(string).
    Message(PNPublishFileMessage).
    CustomMessageType(string).
    Execute()

* required

Parameter	Description
`TTL` Type: int Default: n/a	How long message should be stored in channel's storage.
`Meta` Type: interface Default: n/a	Meta data object which can be used with the filtering ability.
`ShouldStore` Type: bool Default: `true`	Store in `history`.
`Channel` * Type: string Default: n/a	Name of `channel` to publish file message.
`Message` * Type: PNPublishFileMessage Default: n/a	The payload should be of the type `PNPublishFileMessage`.
`CustomMessageType` Type: string Default: n/a	A case-sensitive, alphanumeric string from 3 to 50 characters describing the business-specific label or category of the message. Dashes `-` and underscores `_` are allowed. The value cannot start with special characters or the string `pn_` or `pn-`. Examples: `text`, `action`, `poll`.

Sample code

m := PNPublishMessage{
    Text: "Look at this photo!",
}

file := PNFileInfoForPublish{
    ID:   "d9515cb7-48a7-41a4-9284-f4bf331bc770",
    Name: "cat_picture.jpg",
}

message := PNPublishFileMessage{
    PNFile:    file,
    PNMessage: m,
}
resPubFile, pubFileResponseStatus, errPubFileResponse := pn.PublishFileMessage()
    .Channel("my_channel")
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Returns

The PublishFileMessage() operation returns type PublishFileMessageResponse which contains the following properties:

Property Name	Type	Description
`Timetoken`	int64	Returns a long representation of the timetoken when the `message` was published.

Send file​

Method(s)​

Deprecated parameter

Sample code​

Reference code

Returns​

PNFileData​

List channel files​

Method(s)​

Sample code​

Returns​

PNFileInfo​

Get file URL​

Method(s)​

Sample code​

Returns​

Download file​

Method(s)​

Deprecated parameter

Sample code​

Returns​

Delete file​

Method(s)​

Sample code​

Returns​

Publish file message​

Method(s)​

Sample code​

Returns​

Send file

Method(s)

Sample code

Returns

PNFileData

List channel files

Method(s)

Sample code

Returns

PNFileInfo

Get file URL

Method(s)

Sample code

Returns

Download file

Method(s)

Sample code

Returns

Delete file

Method(s)

Sample code

Returns

Publish file message

Method(s)

Sample code

Returns