ChatView | Permissions

ChatView derives every action affordance from Info.Permissions + ownership (CurrentUserId). There is no per-tool wiring anymore — you set permissions on the ChatSessionInfo your session returns, and the control shows or hides the matching UI automatically.

ChatSessionPermissions

[Flags]
public enum ChatSessionPermissions
{
    None = 0,
    CanSendMessages     = 1,
    CanEditMessages     = 2,    // own messages only
    CanDeleteMessages   = 4,    // own messages only
    CanReactToMessages  = 8,
    CanInviteUsers      = 16,
    CanLeaveSession     = 32,
    CanChangeSessionName= 64,
    CanSendImages       = 128,  // gates the gallery/camera attach affordance (independent of text send)

    Default = CanSendMessages | CanSendImages | CanReactToMessages | CanInviteUsers | CanLeaveSession,
    All = CanSendMessages | CanEditMessages | CanDeleteMessages | CanReactToMessages
        | CanInviteUsers | CanLeaveSession | CanChangeSessionName | CanSendImages
}

Permission → affordance map

Permission	Surfaced as	Calls
CanSendMessages	input bar enabled	SendMessageAsync
CanEditMessages	”Edit” on own bubbles	EditMessageAsync
CanDeleteMessages	”Delete” on own bubbles	DeleteMessageAsync
CanReactToMessages	reaction picker (filtered to PermittedEmojis)	ReactToMessageAsync
CanInviteUsers	invite affordance	InviteUserAsync
CanLeaveSession	leave affordance	LeaveAsync
CanChangeSessionName	rename affordance	RenameAsync
CanSendImages	gallery/camera attach affordance	SendMessageAsync with OutgoingAttachment

Set permissions when you build Info:

public ChatSessionInfo BuildInfo() => new(
    SessionId: this.SessionId,
    SessionName: this.SessionName,
    Users: this.Users,
    PermittedEmojis: null,                                   // null => control default emoji set
    BodyPermissions: MessageBodyPermissions.All,
    Permissions: ChatSessionPermissions.Default,            // or .All, or a hand-picked set
    CreatedAt: this.CreatedAt,
    LastReadDate: this.LastReadDate,
    UnreadMessageCount: this.Unread
);

Changing permissions at runtime is just a matter of refreshing Info and raising SessionUpdated — the control re-derives the affordances.

Common combinations

Goal	Permissions
Read-only feed	None (also set IsInputBarVisible="false")
Text-only, no reactions	CanSendMessages
1:1 chat with edit/delete	CanSendMessages | CanSendImages | CanReactToMessages | CanEditMessages | CanDeleteMessages
Group admin	ChatSessionPermissions.All
Standard member	ChatSessionPermissions.Default

CanSendImages is independent of CanSendMessages, so a session can be image-only, text-only, or both.

MessageBodyPermissions

This separate flags enum drives the markdown composition toolbar (see Markdown & Input Bar). Only granted formats show a toolbar button; None means a plain-text input with no toolbar.

[Flags]
public enum MessageBodyPermissions
{
    None = 0,
    Links = 1, Bold = 2, Italics = 4, Underline = 8, Strikethrough = 16, Codeblocks = 32,
    All = Links | Bold | Italics | Underline | Strikethrough | Codeblocks
}

MessageBodyPermissions is strictly about text formatting — image sending is the CanSendImages action above, not a body flag.

Validation Lives in the Provider

The control never pre-checks size, counts, or content policy — those depend on your server/business rules. It attempts optimistically and renders the verdict you return. Throw the right exception:

// GetSessionAsync: the session is missing or the current user has no access
public class ChatSessionException : Exception
{
    public ChatSessionException(string message) : base(message) { }
}

// SendMessageAsync / ResendMessageAsync / EditMessageAsync: content refused
public class ChatSendRejectedException : Exception
{
    public ChatSendRejectedException(string reason, SendRejectionKind kind) : base(reason)
        => this.Kind = kind;
    public SendRejectionKind Kind { get; }
}

public enum SendRejectionKind
{
    MessageTooLarge, TooManyAttachments, AttachmentTooLarge, UnsupportedContent, NotPermitted, Other
}

Exception	Thrown from	Control reaction
ChatSessionException	GetSessionAsync (and the session methods, for not-found)	renders an error state instead of the chat
ChatSendRejectedException	SendMessageAsync / ResendMessageAsync / EditMessageAsync	flips the optimistic bubble to MessageStatus.Rejected, sets StatusReason, no retry

A transient failure — any other exception — flips the bubble to MessageStatus.Failed with a retry affordance. See Messages & Paging.

Tip

Gate features with permissions and re-validate in the provider. Permissions hide the UI; the provider is the source of truth and re-checks regardless — a permission flag is a UX hint, not a security boundary.

Next Steps

• Markdown & Input Bar — what MessageBodyPermissions enables
• Reactions & Read Receipts — CanReactToMessages + PermittedEmojis
• Custom Actions — append app-specific verbs to the permission-driven set