> ## Documentation Index
> Fetch the complete documentation index at: https://docs.quickblox.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Privacy List
> Learn how to create privacy lists and implement user-to-user blocks.
Privacy list API allows enabling or disabling communication with other users in a chat. You can create, modify, delete privacy lists or define a default list.
The user can have multiple privacy lists, but only one can be active.
Visit [Key Concepts](/docs/key-concepts) page to learn the most important QuickBlox concepts.
## Before you begin
1. Register a [QuickBlox account](https://admin.quickblox.com/signin). This is a matter of a few minutes and you will be able to use this account to build your apps.
2. Configure QuickBlox SDK for your app. Check out [Setup](/sdks/ios-setup) page for more details.
3. Create a user session to be able to use QuickBlox functionality. See [Authentication](/sdks/ios-authentication) page to learn how to do it.
4. Connect to the Chat server. See [Connection](/sdks/ios-chat-connection) page to learn how to do it.
## Create privacy list
A privacy list must have at least one element in order to be created. If no elements are specified, then the list with a given name will be deleted.
```Swift theme={null}
let userID: UInt = 34
let privateChatPrivacyItem = QBPrivacyItem.init(privacyType: .userID, userID: userID, allow: false)
privateChatPrivacyItem.mutualBlock = true
let groupChatPrivacyItem = QBPrivacyItem.init(privacyType: .groupUserID, userID: userID, allow: false)
let privacyList = QBPrivacyList.init(name: "PrivacyList", items: [privateChatPrivacyItem, groupChatPrivacyItem])
//Setting privacy list
QBChat.instance.setPrivacyList(privacyList)
```
```Objective-C theme={null}
NSUInteger userID = 34;
QBPrivacyItem *privateChatPrivacyItem =
[[QBPrivacyItem alloc] initWithPrivacyType:QBPrivacyTypeUserID userID:userID allow:NO];
privateChatPrivacyItem.mutualBlock = YES;
QBPrivacyItem *groupChatPrivacyItem =
[[QBPrivacyItem alloc] initWithPrivacyType:QBPrivacyTypeGroupUserID userID:userID allow:NO];
QBPrivacyList *privacyList =
[[QBPrivacyList alloc] initWithName:@"PrivacyList" items:@[privateChatPrivacyItem,groupChatPrivacyItem]];
//Setting privacy list
[QBChat.instance setPrivacyList:privacyList];
```
If the privacy list is set successfully, the `QBChat` instance will call `chatDidSetPrivacyList(withName:)` delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidSetPrivacyList(withName name: String) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidSetPrivacyListWithName:(NSString *)name {
}
```
In case of error the `QBChat` instance will call the `chatDidNotSetPrivacyList(withName:error:)` delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidNotSetPrivacyList(withName name: String, error: Error) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidNotSetPrivacyListWithName:(NSString *)name error:(NSError *)error {
}
```
In order to be used the privacy list should be not only set but also activated (set as default).
## Activate privacy list
In order to activate rules from a privacy list, you should set it as default.
```Swift theme={null}
QBChat.instance.setDefaultPrivacyListWithName("PrivacyList")
```
```Objective-C theme={null}
[QBChat.instance setDefaultPrivacyListWithName:@"PrivacyList"];
```
If the privacy list is activated, the`QBChat` instance will call the `chatDidSetDefaultPrivacyList(withName:)` method of deledate.
```Swift theme={null}
//MARK: QBQBChatDelegate
func chatDidSetDefaultPrivacyList(withName name: String) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidSetDefaultPrivacyListWithName:(NSString *)name {
}
```
Otherwise, the `QBChat` instance will call `chatDidNotSetDefaultPrivacyList(withName:error:)` delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidNotSetDefaultPrivacyList(withName name: String, error: Error) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidNotSetDefaultPrivacyListWithName:(NSString *)name error:(NSError *)error {
}
```
## Update privacy list
There are some rules you should follow to update a privacy list:
* Include **all** of the desired items (not a "delta").
* If you want to update or set a new privacy list instead of the current one, you should decline the current default list first.
```Swift theme={null}
//Deactivating privacy list before update
QBChat.instance.setDefaultPrivacyListWithName(nil)
//Some updates here
//....
//Activating privacy list
QBChat.instance.setDefaultPrivacyListWithName("PrivacyList")
```
```Objective-C theme={null}
//Deactivating privacy list before update
[QBChat.instance setDefaultPrivacyListWithName:nil];
//Some updates here
//....
//Activating privacy list
[QBChat.instance setDefaultPrivacyListWithName:@"PrivacyList"];
```
## Retrieve privacy lists
To get a list of **all** your privacy lists names, use the following request.
```Swift theme={null}
QBChat.instance.retrievePrivacyListNames()
```
```Objective-C theme={null}
[QBChat.instance retrievePrivacyListNames];
```
If the privacy list names are retrieved successfully, the `QBChat` instance will call `chatDidReceivePrivacyListNames()` delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidReceivePrivacyListNames(_ listNames: [String]) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidReceivePrivacyListNames:(NSArray *)listNames {
}
```
Otherwise, the `QBChat` instance will call `chatDidNotReceivePrivacyListNamesDue(toError:)` delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidNotReceivePrivacyListNamesDue(toError error: Error) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidNotReceivePrivacyListNamesDueToError:(NSError *)error {
}
```
## Retrieve privacy list by name
To get the privacy list by name, you should use the following method.
```Swift theme={null}
QBChat.instance.retrievePrivacyList(withName: "PrivacyList")
```
```Objective-C theme={null}
[QBChat.instance retrievePrivacyListWithName:@"PrivacyList"];
```
If the privacy list is retrieved successfully, the `QBChat` instance will call `chatDidReceive(_ privacyList:)` its delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidReceive(_ privacyList: QBPrivacyList) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidReceivePrivacyList:(QBPrivacyList *)privacyList {
}
```
Otherwise, the `QBChat` instance will call `chatDidNotReceivePrivacyList(withName:error)` delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidNotReceivePrivacyList(withName name: String, error: Error) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidNotReceivePrivacyListWithName:(NSString *)name error:(NSError *)error {
}
```
## Remove privacy list
To delete a list, you can call the method below or you can edit a list and set items to `nil`.
```Swift theme={null}
QBChat.instance.removePrivacyList(withName: "PrivacyList")
```
```Objective-C theme={null}
[QBChat.instance removePrivacyListWithName:@"PrivacyList"];
```
If the privacy list is removed successfully, the `QBChat` instance will call `chatDidRemovedPrivacyList(withName:)` delegate method.
```Swift theme={null}
//MARK: QBChatDelegate
func chatDidRemovedPrivacyList(withName name: String) {
}
```
```Objective-C theme={null}
//MARK: QBChatDelegate
- (void)chatDidRemovedPrivacyListWithName:(NSString *)name {
}
```
Before deleting the privacy list, you should decline it.
## Blocked user attempts to communicate with user
A user can be blocked in **1-1 dialog** and **group dialog**. In this case, the blocked user receives an error when trying to send a message in a **1-1 dialog** and receives nothing when trying to send a message in **group dialog**.
```Swift theme={null}
chatDialog.onBlockedMessage = { (error) in
}
```
```Objective-C theme={null}
chatDialog.onBlockedMessage = ^(NSError * _Nullable error) {
};
```