ShortCut Formatter

Implement message shortcuts using the ShortCutFormatter class in CometChat UI Kit for iOS

Introduction

The ShortCutFormatter class extends the CometChatTextFormatter class to provide a mechanism for handling shortcuts within messages. This guide walks you through the process of using ShortCutFormatter to implement shortcut extensions in your CometChat application.

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Setup

1. Create the ShortCutFormatter Class

Define the ShortCutFormatter class by extending the CometChatTextFormatter class:

Swift

class ShortcutFormatter: CometChatTextFormatter {
    
    // Store fetched shortcuts from the extension
    private var messageShortcuts: [String: String] = [:]
    
    // Store suggestion items for display
    private var shortcuts: [CometChatUIKitSwift.SuggestionItem] = []
}

2. Initialize with Tracking Character

Set the trackingCharacter to '!' in the initializer:

Swift

override init(trackingCharacter: Character) {
    super.init(trackingCharacter: "!")
}

3. Define the Regex Pattern

Set the regular expression for shortcut detection in the getRegex() method:

Swift

override func getRegex() -> String {
    return "(^|\\s)!\\w+"
}

4. Return the Tracking Character

Define the getTrackingCharacter() method to return '!' as the shortcut tracking character:

Swift

override func getTrackingCharacter() -> Character {
    return "!"
}

5. Implement the Search Method

Override the search() method to search for shortcuts based on the entered query:

Swift

override func search(string: String, suggestedItems: (([CometChatUIKitSwift.SuggestionItem]) -> ())? = nil) {
    
    // Fetch shortcuts from extension if not already cached
    if messageShortcuts.isEmpty {
        CometChat.callExtension(
            slug: "message-shortcuts",
            type: .get,
            endPoint: "v1/fetch",
            body: nil
        ) { [weak self] extensionResponseData in
            guard let self = self else { return }
            
            if let shortcutData = extensionResponseData?["shortcuts"] as? [String: String] {
                self.messageShortcuts = shortcutData
                
                // Filter shortcuts matching the search string
                let suggestedItemsList = self.messageShortcuts
                    .filter { $0.key.hasPrefix(string) }
                    .map { CometChatUIKitSwift.SuggestionItem(id: $0.key, name: $0.value, visibleText: $0.value) }
                
                suggestedItems?(suggestedItemsList)
            }
        } onError: { error in
            print("Error occurred while fetching shortcuts: \(error?.errorDescription ?? "Unknown error")")
        }
    } else {
        // Use cached shortcuts
        let suggestedItemsList = messageShortcuts
            .filter { $0.key.hasPrefix(string) }
            .map { CometChatUIKitSwift.SuggestionItem(id: $0.key, name: $0.value, visibleText: $0.value) }
        
        suggestedItems?(suggestedItemsList)
    }
}

6. Handle Message String Preparation

Implement the prepareMessageString() method to convert the base chat message into an attributed string for display:

Swift

override func prepareMessageString(
    baseMessage: BaseMessage,
    regexString: String,
    alignment: MessageBubbleAlignment = .left,
    formattingType: FormattingType
) -> NSAttributedString {
    let message = (baseMessage as? TextMessage)?.text ?? ""
    return NSAttributedString(string: message)
}

7. Handle Text Tap Events

Override the onTextTapped() method if you need to handle tap events on formatted text:

Swift

override func onTextTapped(baseMessage: BaseMessage, tappedText: String, controller: UIViewController?) {
    // Handle tap event on shortcut text
}

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Complete Implementation

Here’s the complete ShortcutFormatter class:

Swift

import Foundation
import CometChatSDK
import CometChatUIKitSwift

class ShortcutFormatter: CometChatTextFormatter {
    
    // MARK: - Properties
    
    private var messageShortcuts: [String: String] = [:]
    private var shortcuts: [CometChatUIKitSwift.SuggestionItem] = []
    
    // MARK: - Initialization
    
    override init(trackingCharacter: Character) {
        super.init(trackingCharacter: "!")
    }
    
    // MARK: - Override Methods
    
    override func getRegex() -> String {
        return "(^|\\s)!\\w+"
    }
    
    override func getTrackingCharacter() -> Character {
        return "!"
    }
    
    override func search(string: String, suggestedItems: (([CometChatUIKitSwift.SuggestionItem]) -> ())? = nil) {
        
        if messageShortcuts.isEmpty {
            CometChat.callExtension(
                slug: "message-shortcuts",
                type: .get,
                endPoint: "v1/fetch",
                body: nil
            ) { [weak self] extensionResponseData in
                guard let self = self else { return }
                
                if let shortcutData = extensionResponseData?["shortcuts"] as? [String: String] {
                    self.messageShortcuts = shortcutData
                    
                    let suggestedItemsList = self.messageShortcuts
                        .filter { $0.key.hasPrefix(string) }
                        .map { CometChatUIKitSwift.SuggestionItem(id: $0.key, name: $0.value, visibleText: $0.value) }
                    
                    suggestedItems?(suggestedItemsList)
                }
            } onError: { error in
                print("Error occurred while fetching shortcuts: \(error?.errorDescription ?? "Unknown error")")
            }
        } else {
            let suggestedItemsList = messageShortcuts
                .filter { $0.key.hasPrefix(string) }
                .map { CometChatUIKitSwift.SuggestionItem(id: $0.key, name: $0.value, visibleText: $0.value) }
            
            suggestedItems?(suggestedItemsList)
        }
    }
    
    override func prepareMessageString(
        baseMessage: BaseMessage,
        regexString: String,
        alignment: MessageBubbleAlignment = .left,
        formattingType: FormattingType
    ) -> NSAttributedString {
        let message = (baseMessage as? TextMessage)?.text ?? ""
        return NSAttributedString(string: message)
    }
    
    override func onTextTapped(baseMessage: BaseMessage, tappedText: String, controller: UIViewController?) {
        // Handle tap event on shortcut text
    }
}

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Usage

1. Initialize the Formatter

Create an instance of ShortCutFormatter:

Swift

let shortcutFormatter = ShortcutFormatter(trackingCharacter: "!")

2. Integrate with Message Composer

If you’re using the CometChatMessageComposer component, integrate the ShortCutFormatter to manage shortcut functionalities:

Swift

let shortcutFormatter = ShortcutFormatter(trackingCharacter: "!")

let cometChatMessageComposer = CometChatMessageComposer()
cometChatMessageComposer.set(textFormatter: [shortcutFormatter])

Ensure to pass and present cometChatConversationsWithMessages. If a navigation controller is already in use, utilize the pushViewController function instead of directly presenting the view controller.

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Example

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Next Steps

Mentions Formatter

Add @mentions with styled tokens and click handling.

Message Composer

Customize the message input component.

Message List

Display and customize chat messages.

Message Template

Define custom message bubble structures.

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