When working with Supabase, a popular open-source backend-as-a-service platform, many developers encounter the createClient function from the supabase-js library. The question arises: Does calling this function create a singleton instance, and is it memory efficient to call it multiple times? This article aims to clarify this concept and offer practical advice for developers, especially those working with React Native.
Understanding createClient
The createClient function initializes a new Supabase client. This client allows you to communicate with your Supabase database, perform operations like authentication, and manage data. Here’s a typical example of how it’s used:
import { createClient } from '@supabase/supabase-js';
const supabaseUrl = process.env.SUPABASE_URL;
const supabaseKey = process.env.SUPABASE_KEY;
const supabase = createClient(supabaseUrl, supabaseKey);
The Singleton Pattern
A singleton is a design pattern that restricts a class to a single instance and provides a global point of access to that instance. In the context of createClient, if it were a singleton, calling it multiple times would return the same client instance every time.
Analysis of createClient Behavior
According to a Stack Overflow post by user benmcl, there is a common pattern emerging in tutorials:
const supabaseClient = (supabaseAccessToken) => {
const supabase = createClient(
process.env.SUPABASE_URL,
process.env.SUPABASE_KEY,
{
global: { headers: { Authorization: `Bearer ${supabaseAccessToken}` } }
}
);
return supabase;
};
In this example, createClient is called every time a fetch operation is performed, which raises concerns about memory usage, especially in a React Native context where performance and efficiency are crucial.
Is it a Memory Issue?
In React Native, repeatedly calling createClient does not create a singleton. Each call generates a new instance of the client, which can lead to increased memory usage if done excessively. This is particularly relevant in mobile environments where resources are limited.
Practical Example
If your application needs to fetch data with the latest authorization token each time, consider the following pattern:
const fetchData = async (supabaseAccessToken) => {
const supabase = createClient(
process.env.SUPABASE_URL,
process.env.SUPABASE_KEY,
{
global: { headers: { Authorization: `Bearer ${supabaseAccessToken}` } }
}
);
const { data, error } = await supabase
.from('table')
.select('*');
if (error) {
console.error('Error fetching data:', error);
return null;
}
return data;
};
Recommendations for React Native Developers
-
Create a Singleton Client: Instead of creating a new instance every time, create a singleton client instance at the module level:
import { createClient } from '@supabase/supabase-js'; const supabaseUrl = process.env.SUPABASE_URL; const supabaseKey = process.env.SUPABASE_KEY; const supabase = createClient(supabaseUrl, supabaseKey); -
Update Tokens When Necessary: You can still update the authorization headers when necessary without creating a new client:
supabase.auth.setAuth(supabaseAccessToken); -
Monitor Memory Usage: Use profiling tools available in React Native to monitor memory usage, ensuring that the application remains efficient.
Conclusion
While the createClient function from Supabase does not create a singleton instance, developers should be mindful of how they utilize it in applications, particularly in environments like React Native. Creating a single instance and updating the necessary headers when required can help maintain performance and resource efficiency. This knowledge not only enhances application performance but also contributes to a smoother user experience.
Additional Resources
By understanding the implications of your client management strategy, you can create more robust and efficient applications using Supabase.
