Developer Documentation: useProfileActions Hook

This documentation explains the useProfileActions hook, which provides actions for interacting with a user's profile, such as adding friends and sending messages in a Firebase-authenticated React Native application.

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Overview

The useProfileActions hook:

1. Enables users to send friend requests by updating the Firestore database.
2. Facilitates navigation to a chat screen for messaging.
3. Tracks loading states for friend addition actions.

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Features and Functionality

1. Adding Friends

Purpose

• Allows the current user to add another user as a friend by updating both users' Firestore friends arrays.

Implementation

1. Functionality:

   • Ensures the user is logged in before proceeding.
   • Updates the friends array of both the current user and the friend in the users collection.

2. Code Snippet:

   const handleAddFriend = async () => {
     if (!currentUser) return; // Ensure the user is logged in
     setLoading(true);
     try {
       const currentUserDocRef = doc(db, 'users', currentUser.uid);
       const ownerUserDocRef = doc(db, 'users', ownerId);
   
       await updateDoc(currentUserDocRef, {
         friends: arrayUnion(ownerId),
       });
       await updateDoc(ownerUserDocRef, {
         friends: arrayUnion(currentUser.uid),
       });
   
       Alert.alert('Success', 'You are now friends!');
     } catch (error) {
       console.error('Error adding friend:', error);
       Alert.alert('Error', 'There was an error adding this user as a friend.');
     } finally {
       setLoading(false);
     }
   };
   

3. Process:

   • Retrieves references to both the current user's and friend's documents in Firestore.
   • Uses arrayUnion to add the friend’s UID to the friends array while avoiding duplicates.
   • Displays an alert on success or error.

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2. Sending Messages

Purpose

• Navigates to a chat screen with a unique chat ID generated based on the current user and the profile owner's UID.

Implementation

1. Functionality:

   • Checks if the user is logged in before proceeding.
   • Creates a chat ID by sorting and concatenating the current user's and owner's UIDs.
   • Navigates to the Chat screen with the generated chatId.

2. Code Snippet:

   const handleSendMessage = () => {
     console.log('Send Message pressed');
     const currentUserId = currentUser?.uid;
     if (!currentUserId) {
       console.error('User not authenticated');
       return;
     }
     const chatId = [currentUserId, ownerId].sort().join('_');
     navigation.navigate('Chat', { chatId });
   };
   

3. Process:

   • Validates user authentication.
   • Generates a deterministic chat ID to ensure consistency for the same pair of users.
   • Passes the chatId to the Chat screen via navigation.

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3. Loading State

Purpose

• Tracks the state of asynchronous operations, such as adding a friend.

Implementation

1. Functionality:

   • Sets loading to true before starting an operation and resets it to false when completed.

2. Code Snippet:

   const [loading, setLoading] = useState(false);
   

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Key Properties and Methods

Property/Method	Description
handleAddFriend	Adds the profile owner as a friend to the current user's friend list.
handleSendMessage	Navigates to the Chat screen with a unique chatId for messaging.
loading	Tracks whether the handleAddFriend operation is in progress.

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Usage Example

import React from 'react';
import { Button } from 'react-native';
import { useProfileActions } from './hooks/useProfileActions';

const ProfileScreen = ({ ownerId }: { ownerId: string }) => {
  const { handleAddFriend, handleSendMessage, loading } = useProfileActions(ownerId);

  return (
    <>
      <Button title="Add Friend" onPress={handleAddFriend} disabled={loading} />
      <Button title="Send Message" onPress={handleSendMessage} />
    </>
  );
};

export default ProfileScreen;

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Error Handling

• Authentication Errors:

  • Ensures the user is logged in before performing actions.
  • Logs errors and displays alerts for unauthenticated users.

• Firestore Errors:

  • Logs errors and displays alerts if updating the friends array fails.

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Notes

• Friendship Relationship:

  • The friends array is updated bi-directionally, ensuring both users see each other as friends.

• Chat ID Generation:

  • The chat ID is deterministic and consistent for a pair of users to avoid duplication.

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For more details, refer to the Firebase Firestore Documentation and React Navigation Documentation.