Optimize Page Load Times with Effective API Call Management in Blazor WebAssembly

Discover strategies to reduce page load times in your Blazor WebAssembly applications by optimizing multiple API calls and implementing efficient data handling techniques.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Multiple API calls slow down the page upload

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Optimize Page Load Times with Effective API Call Management in Blazor WebAssembly

When developing a Blazor WebAssembly application, efficient data retrieval is crucial for providing a smooth user experience. The challenge arises when your application makes multiple API calls, especially when dealing with large datasets. In this post, we will explore how to tackle the common issue of slow page uploads when multiple API calls are taking place.

The Problem: Slow Loading from Multiple API Calls

Imagine you have a Blazor WebAssembly application composed of a frontend and a .NET Core WebAPI project. On a particular Razor page, you're required to make five separate API calls to fetch data from various database tables, each containing over 60,000 records. This can lead to noticeably slow page load times because:

Each API call has to execute, which can lead to delays.

Large data sets are pulled, serialized, and then transmitted over the network.

The sample code provided highlights this issue well, as the performance bottleneck occurs in the OnInitializedAsync method, where several API calls are made in sequence.

The Solution: Improving API Call Efficiency

Here are some actionable strategies to enhance the performance of your Blazor WebAssembly application by optimizing API calls and data handling:

1. Use Data Transfer Objects (DTOs)

Instead of transferring entire entities, consider using View Models or DTOs. This approach minimizes the data sent over the network by focusing only on the fields required for the frontend. For example, if you only need an ID and a display name for lookups, your API can return a simplified object:

[[See Video to Reveal this Text or Code Snippet]]

Use the Select method in your query to only pick the needed fields:

[[See Video to Reveal this Text or Code Snippet]]

2. Implement Server-Side Pagination

When dealing with large datasets, loading everything at once is not practical. Instead, implement server-side pagination:

What is Server-Side Pagination? It allows the backend to send only a subset of data to the client rather than the entire dataset. Users can request specific pages, which significantly reduces the amount of data transmitted.

Benefits:

The user interface remains responsive.

Reduces memory usage on both the client and server.

Here's how it might look in a controller:

[[See Video to Reveal this Text or Code Snippet]]

3. Minimize Data Fetching

Assess how much data is truly necessary for the frontend. Consider whether you can consolidate requests or adjust the timing of when data is fetched, so it is not all loaded at once.

Lazy Loading vs. Eager Loading: Be mindful of lazy loading, as it may incur additional queries during serialization. Profiling can help identify unexpected database calls.

4. Optimize Subsequent Operations

Once the page is loaded, the response times for saving, updating, and deleting records may remain fast. This indicates that the bottleneck mainly resides in the initial data loading. Therefore, focus on optimizing the fetching process initially.

Conclusion

In summary, multiple API calls in a Blazor WebAssembly application can create a sluggish user experience, especially when large datasets are involved. By implementing strategies like using DTOs, enabling server-side pagination, and minimizing the amount of data fetched, you can significantly enhance your application's performance and user satisfaction.

By carefully balancing the amount of data sent and optimizing how that data is retrieved and processed, you can improve your application’s responsiveness and create a smoother, more engaging user experience. Happy coding!