ShortCut Formatter

Overview

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

Usage

Here are the steps to create a ShortCutFormatter for CometChat using the CometChatTextFormatter:

1. Firstly, you need to import CometChatTextFormatter from the CometChat UI Kit angular library.

import { CometChatTextFormatter } from "@cometchat/chat-uikit-angular";

2. Now, extend the CometChatTextFormatter class to create your custom text formatter class. In this case, let’s create a HashTagTextFormatter.

class ShortCutFormatter extends CometChatTextFormatter {
  ...
}

3. Set up the trackCharacter and define any necessary private fields.

this.setTrackingCharacter("!");

4. Implement the onKeyDown method to handle key events and trigger actions based on defined shortcuts.

onKeyDown(event: KeyboardEvent) {
  // Your implementation
}

5. Implement any additional methods required for your custom formatter, such as opening and closing dialogs, handling button clicks, and formatting text.

openDialog(buttonText: string) {
  // Your implementation
}

closeDialog() {
  // Your implementation
}

handleButtonClick = () => {
  // Your implementation
};

getFormattedText(text: string): string {
  return text;
}

private getTextBeforeCaret(caretPosition: number): string {
  // Your implementation
}

Example

Below is an example demonstrating how to use a custom formatter class in components such as CometChatConversations, CometChatMessageList, CometChatMessageComposer.

ShortCutFormatter.ts

import { CometChatTextFormatter } from "@cometchat/uikit-shared";
import { Subject } from 'rxjs';
import { CometChat } from "@cometchat/chat-sdk-javascript";

export class ShortcutFormatter extends CometChatTextFormatter {
    private shortcuts: { [key: string]: string } = {};
    private dialogIsOpen: boolean = false;
    private currentShortcut: string | null = null;
    private openDialogSubject = new Subject<{ closeDialog?: boolean, buttonText?: string, shortcut?: string, handleButtonClick?:any }>();
    openDialog$ = this.openDialogSubject.asObservable();

    constructor() {
        super();
        this.setTrackingCharacter('!');
        CometChat.callExtension('message-shortcuts', 'GET', 'v1/fetch', undefined)
            .then((data: any) => {
                if (data && data.shortcuts) {
                    this.shortcuts = data.shortcuts;
                }
            })
            .catch(error => console.log("error fetching shortcuts", error));
    }

    override onKeyDown(event: KeyboardEvent) {
        const caretPosition = this.currentCaretPosition instanceof Selection
            ? this.currentCaretPosition.anchorOffset
            : 0;
        const textBeforeCaret = this.getTextBeforeCaret(caretPosition);

        const match = textBeforeCaret.match(/!([a-zA-Z]+)$/);
        if (match) {
            const shortcut = match[0];
            const replacement = this.shortcuts[shortcut];
            if (replacement) {
                if (this.dialogIsOpen && this.currentShortcut !== shortcut) {
                    this.closeDialog();
                }
                this.openDialog(replacement, shortcut);
            }
        }
    }

    getCaretPosition() {
        if (!this.currentCaretPosition?.rangeCount) return { x: 0, y: 0 };
        const range = this.currentCaretPosition?.getRangeAt(0);
        const rect = range.getBoundingClientRect();
        return {
            x: rect.left,
            y: rect.top
        };
    }

    openDialog(buttonText: string, shortcut: string) {
        this.openDialogSubject.next({ buttonText, shortcut , handleButtonClick: this.handleButtonClick});
        this.dialogIsOpen = true;
        this.currentShortcut = shortcut;
    }

    closeDialog() {
        this.openDialogSubject.next({closeDialog: true});
    }

    handleButtonClick = (buttonText: string) => {
        console.log(buttonText);
        
        if (this.currentCaretPosition && this.currentRange) {
            const shortcut = Object.keys(this.shortcuts).find(key => this.shortcuts[key] === buttonText);
            if (shortcut) {
                const replacement = this.shortcuts[shortcut];
                this.addAtCaretPosition(replacement, this.currentCaretPosition, this.currentRange);
            }
        }
        if (this.dialogIsOpen) {
            this.closeDialog();
        }
    };

    override getFormattedText(text: string): string {
        return text;
    }

    private getTextBeforeCaret(caretPosition: number): string {
        if (this.currentRange && this.currentRange.startContainer && typeof this.currentRange.startContainer.textContent === "string") {
            const textContent = this.currentRange.startContainer.textContent;
            if (textContent.length >= caretPosition) {
                return textContent.substring(0, caretPosition);
            }
        }
        return "";
    }
}

export default ShortcutFormatter;

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