Updating a Channel

There are two ways to update a channel using the Stream API - a partial or full update. A partial update will retain any custom key-value data, whereas a complete update is going to remove any that are unspecified in the API request.

Partial Update

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

// Create a channel with some custom field data that might be useful
FChannelProperties Props = FChannelProperties{Type, Id};

// Set extra data using dynamic JSON. You'd more likely want to use statically typed structs.
Props.ExtraData.SetString(TEXT("source"), TEXT("user"));
const TSharedRef<FJsonObject> SourceDetail = MakeShared<FJsonObject>();
SourceDetail->SetNumberField(TEXT("user_id"), 123);
Props.ExtraData.SetJsonValue(TEXT("source_detail"), MakeShared<FJsonValueObject>(SourceDetail));
const TSharedRef<FJsonObject> ChannelDetail = MakeShared<FJsonObject>();
ChannelDetail->SetStringField(TEXT("topic"), TEXT("Plants and Animals"));
ChannelDetail->SetStringField(TEXT("rating"), TEXT("pg"));
Props.ExtraData.SetJsonValue(TEXT("source_detail"), MakeShared<FJsonValueObject>(ChannelDetail));
Client->CreateChannel(
  Props,
  [](UChatChannel* Channel)
  {
    // let's change the source of this channel
    const TSharedRef<FJsonObject> NewSource = MakeShared<FJsonObject>();
    NewSource->SetStringField(TEXT("source"), TEXT("system"));
    Channel->PartialUpdate(NewSource);

    // since it's system generated we no longer need source_detail
    Channel->PartialUpdate({}, {TEXT("source_detail")});

    // and finally update one of the nested fields in the channel_detail
    const TSharedRef<FJsonObject> NewTopic = MakeShared<FJsonObject>();
    NewSource->SetStringField(TEXT("channel_detail.topic"), TEXT("Nature"));
    Channel->PartialUpdate(NewSource);

    // and maybe we decide we no longer need a rating
    Channel->PartialUpdate({}, {TEXT("channel_detail.rating")});
  });

Full Update (overwrite)

The update function updates all of the channel data. Any data that is present on the channel and not included in a full update will be deleted.

FAdditionalFields Data;
Data.SetString(TEXT("name"), TEXT("myspecialchannel"));
Data.SetString(TEXT("color"), TEXT("green"));
const FMessage Message{TEXT("Thierry changed the channel color to green")};
Channel->Update(Data, Message);

Request Params

NameTypeDescriptionOptional
channel dataobjectObject with the new channel information. One special field is “frozen”. Setting this field to true will freeze the channel. Read more about freezing channels in “Freezing Channels”
textobjectMessage object allowing you to show a system message in the Channel that something changed.Yes

Updating a channel using these methods cannot be used to add or remove members. For this, you must use specific methods for adding/removing members, more information can be found here.

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