Manage the user-channel membership relation

Requires App Context

Enable App Context for your keyset in the Admin Portal.

A Membership entity is created when a user joins or is invited to a channel, and ends when the user leaves.

You can use PubNub's functionality via Blueprints or directly in C++ code.

• In Blueprints, you can access PubNub from any Widget or Actor. Start by initializing chat using InitChat on UPubnubChatSubsystem. Afterwards, you can use the returned UPubnubChat object reference to call all Chat SDK functions.

Blueprint functions

The Blueprints provided in the documentation show how you can structure your application and may contain utility methods and elements like buttons that are not part of the Unreal Chat SDK and are meant to serve as guidance.

• In C++, you can use UPubnubChatSubsystem as any other Game Instance Subsystem.

  1
  

  Chat now allows you to call all Chat SDK functions, for example, Chat->GetChannel("my_channel").

Usage in Blueprints and C++

Asynchronous and synchronous method execution

Most PubNub Unreal SDK methods are available in both asynchronous and synchronous variants.

• Asynchronous methods (Async suffix) return void and take an optional delegate parameter that fires when the operation completes.

  1Channel->GetMembersAsync(OnGetMembersResponseDelegate);

  You can also use native callbacks that accept lambdas instead of dynamic delegates. Native callback types have the Native suffix (for example, FOnPubnubChatMembershipsResponseNative).

• Synchronous methods (no suffix) block the main game thread until the operation completes and return a result struct directly.

  1FPubnubChatMembershipsResult Result = Channel->GetMembers();

Get members

Get all members of a channel with GetMembers().

Method signature

Blueprint

C++ / Input parameters

1Channel->GetMembers(
2    int Limit = 0, 
3    FString Filter = "", 
4    FPubnubMemberSort Sort = ..., 
5    FPubnubPage Page = FPubnubPage()
6);

* required

Parameter	Description
Limit Type: int Default: 0	Number of objects to return in response. The default (and maximum) value is 100.
Filter Type: FString Default: ""	Expression used to filter the results. Returns only these channels whose properties satisfy the given expression are returned. The filter language is defined here.
Sort Type: FPubnubMemberSort Default: n/a	Struct used to specify a property to sort by and sort direction. Available options are id, name, and updated. Use asc or desc to specify the sorting direction. By default, the items are sorted by the last updated date.
Page Type: FPubnubPage Default: FPubnubPage()	Object used for pagination to define which previous or next result page you want to fetch.
> Next Type: FString 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.
> Prev Type: FString Default: n/a	Random string returned from the server, indicating a specific position in a data set. Used for backward pagination, it fetches the previous page, enabling access to earlier data. Ignored if the Next parameter is supplied.

Output

Parameter	Description
FPubnubChatMembershipsResult Type: struct	Returned object containing these fields: Result, Memberships, Page, and Total.
> Result Type: FPubnubChatOperationResult	Contains Error and ErrorMessage for operation status.
> Memberships Type: TArray<UPubnubChatMembership*>	Array of all related memberships.
> Page Type: FPubnubPage	Object used for pagination to define which previous or next result page you want to fetch.
>> Next Type: FString	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.
>> Prev Type: FString	Random string returned from the server, indicating a specific position in a data set. Used for backward pagination, it fetches the previous page, enabling access to earlier data. Ignored if the Next parameter is supplied.
> Total Type: int	Total number of channel members.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Get channel members with user data asynchronously.

C++

Actor.h

1

Actor.cpp

1

Blueprint

Get member

Get a specific channel member by user ID with GetMember().

Method signature

C++ / Input parameters

1Channel->GetMember(const FString UserID);

* required

Parameter	Description
UserID * Type: FString Default: n/a	Unique identifier of the user to retrieve the membership for.

Blueprint

Output

Parameter	Description
FPubnubChatMembershipResult Type: struct	Returned object containing Result and Membership.
> Result Type: FPubnubChatOperationResult	Contains Error and ErrorMessage for operation status.
> Membership Type: UPubnubChatMembership*	Membership of the specified user, or nullptr if they are not a member.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Get the membership of a user on the current channel.

Actor.h

1

Actor.cpp

1

Check member

Check if a specific user is a member of the channel with HasMember().

Method signature

C++ / Input parameters

1Channel->HasMember(const FString UserID);

* required

Parameter	Description
UserID * Type: FString Default: n/a	Unique identifier of the user to check.

Blueprint

Output

Parameter	Description
FPubnubChatHasMemberResult Type: struct	Returned object containing Result and HasMember.
> Result Type: FPubnubChatOperationResult	Contains Error and ErrorMessage for operation status.
> HasMember Type: bool	true if the user is a member of the channel; false otherwise.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Check if a user is a member of the current channel.

Actor.h

1

Actor.cpp

1

Get membership

Get all channel memberships for a user with GetMemberships().

To list all channels, use GetChannels() instead.

C++ / Input parameters

1User->GetMemberships(
2    const int Limit = 0,
3    const FString Filter = "",
4    FPubnubMembershipSort Sort = FPubnubMembershipSort(),
5    FPubnubPage Page = FPubnubPage()
6);

* required

Parameter	Description
Limit Type: int Default: 0	Number of objects to return in response. Pass 0 to use the server default.
Filter Type: FString Default: ""	Expression used to filter the results. Returns only these channels whose properties satisfy the given expression. The filter language is defined here.
Sort Type: FPubnubMembershipSort Default: n/a	Struct defining the property to sort by, and a sort direction. Available options are id, name, and updated.
Page Type: FPubnubPage Default: n/a	Object used for pagination to define which previous or next result page you want to fetch.
> Next Type: FString 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.
> Prev Type: FString Default: n/a	Random string returned from the server, indicating a specific position in a data set. Used for backward pagination, it fetches the previous page, enabling access to earlier data. Ignored if the Next parameter is supplied.

Blueprint

Output

Parameter	Description
FPubnubChatMembershipsResult Type: struct	Returned object containing these fields: Page, Total, Result, and Memberships.
> Page Type: FPubnubPage	Object used for pagination to define which previous or next result page you want to fetch.
>> Next Type: FString	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.
>> Prev Type: FString	Random string returned from the server, indicating a specific position in a data set. Used for backward pagination, it fetches the previous page, enabling access to earlier data. Ignored if the Next parameter is supplied.
> Total Type: int	Total number of channel members.
> Result Type: FPubnubChatOperationResult	Contains Error and ErrorMessage for operation status.
> Memberships Type: TArray<UPubnubChatMembership*>	Array of all related memberships.

Sample code

Find out which channels the support_agent_15 user is a member of.

C++

1

Blueprint

Get single membership

Get a user's membership on a specific channel with GetMembership().

Method signature

C++ / Input parameters

1User->GetMembership(const FString ChannelID);

* required

Parameter	Description
ChannelID * Type: FString Default: n/a	ID of the channel to retrieve the user's membership for.

Blueprint

Output

Parameter	Description
FPubnubChatMembershipResult Type: struct	Returned object containing Result and Membership.
> Result Type: FPubnubChatOperationResult	Contains Error and ErrorMessage for operation status.
> Membership Type: UPubnubChatMembership*	The user's membership on the specified channel, or nullptr if not a member.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Get the membership of a user on a specific channel.

Actor.h

1

Actor.cpp

1

Check channel membership

Check if a user is a member of a specific channel with IsMemberOn().

Method signature

C++ / Input parameters

1User->IsMemberOn(const FString ChannelID);

* required

Parameter	Description
ChannelID * Type: FString Default: n/a	ID of the channel to check membership on.

Blueprint

Output

Parameter	Description
FPubnubChatIsMemberOnResult Type: struct	Returned object containing Result and IsMemberOn.
> Result Type: FPubnubChatOperationResult	Contains Error and ErrorMessage for operation status.
> IsMemberOn Type: bool	true if the user is a member of the specified channel; false otherwise.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Check if a user is a member of a specific channel.

Actor.h

1

Actor.cpp

1

Get updates

Receive updates when Membership objects are edited or removed:

• StreamUpdates() - monitors a single membership
• StreamUpdatesOn() - monitors multiple memberships (static method)

Both methods return FPubnubChatOperationResult. Updates are delivered via the membership's OnUpdated delegate (with channel ID, user ID, and data) and deletions via the OnDeleted delegate. Bind these delegates before calling StreamUpdates() or StreamUpdatesOn().

Stream update behavior

• StreamUpdates() delivers updates via the membership's OnUpdated delegate (with channel ID, user ID, and data) and deletions via OnDeleted delegate.

• StreamUpdatesOn() delivers updates on any of the monitored memberships via the same delegate pattern.

• To stop receiving updates, call StopStreamingUpdates() or StopStreamingUpdatesAsync() on the membership.

Method signature

C++ / Input parameters

• StreamUpdates()

  1Membership->StreamUpdates();

• StreamUpdatesOn() (static)

  1UPubnubChatMembership::StreamUpdatesOn(const TArray<UPubnubChatMembership*>& Memberships);

Blueprint

Parameter	Required in StreamUpdates()	Required in StreamUpdatesOn()	Description
Memberships Type: TArray<UPubnubChatMembership*> Default: n/a	No	Yes	Array of Membership objects for which you want to get updates.

Output

Type	Description
FPubnubChatOperationResult	Contains Error (bool) and ErrorMessage (FString). Check Error to determine if the operation succeeded.

Sample code

Stream updates on a membership and stop when no longer needed.

C++

1

Blueprint

Stopping updates

To stop receiving membership updates, call StopStreamingUpdates() or StopStreamingUpdatesAsync() on the membership.

Update

Update a user's channel membership information with Update().

Method signature

C++ / Input parameters

1Membership->Update(FPubnubChatUpdateMembershipInputData UpdateMembershipData);

Type	Description
FPubnubChatUpdateMembershipInputData	The object containing the membership fields to update.

FPubnubChatUpdateMembershipInputData

* required

Parameter	Description
Custom Type: FString Default: n/a	JSON custom data associated with the membership.
Status Type: FString Default: n/a	Status of the membership.
Type Type: FString Default: n/a	Type of the membership.
ForceSetCustom Type: bool Default: false	When true, overwrites the custom data even if empty.
ForceSetStatus Type: bool Default: false	When true, overwrites the status even if empty.
ForceSetType Type: bool Default: false	When true, overwrites the type even if empty.

Blueprint

Output

Type	Description
FPubnubChatOperationResult	Contains Error (bool) and ErrorMessage (FString). Check Error to determine if the operation succeeded. The membership is updated in place.

Sample code

Update a membership's status to active.

C++

1

Blueprint

Get membership data

GetMembershipData() returns the channel membership data for a given user.

Method signature

C++ / Input parameters

1Membership->GetMembershipData();

Blueprint

Output

Type	Description
FPubnubChatMembershipData	The object containing all membership data.

FPubnubChatMembershipData

Parameter	Description
Custom Type: FString	Custom data associated with the membership.
Status Type: FString	Status of the membership.
Type Type: FString	Type of the membership.

Sample code

Get the membership data for a membership.

C++

1

Blueprint

Other examples

These accessors return the user or channel associated with a membership. They are local getters and do not make network calls.

Get user

Get channel

Get user ID

Get channel ID

Delete

Remove a user's channel membership with Delete(). This removes the user from the channel's members on the server.

Method signature

C++ / Input parameters

1Membership->Delete();

Blueprint

Output

Type	Description
FPubnubChatOperationResult	Contains Error (bool) and ErrorMessage (FString). Check Error to determine if the operation succeeded.

Sample code

Delete a membership.

C++

1

Blueprint