Скачать или смотреть How to Fix File Upload Issues from Angular to NodeJS Backend

Discover simple steps to troubleshoot and resolve file upload problems from your Angular frontend to a NodeJS backend and API.
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Troubleshooting File Upload from Angular to NodeJS Backend

In web development, transferring files from a client application to a server can pose challenges. One common issue developers face is successfully forwarding files from an Angular frontend to a NodeJS backend, and subsequently to a NodeJS API. If you are encountering empty file requests at your API endpoint, you're not alone. This guide will walk you through the problem and provide a detailed solution to get your file uploads working seamlessly.

The Problem

In our setup, we have:

An Angular frontend that captures file uploads using a form.

A NodeJS web backend that receives the file and forwards it to an API built in NodeJS.

However, upon trying to upload files, we noticed that the API output displays:

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

This indicates that no files are being recognized in the request sent to the API, despite having files present in the backend.

Understanding the Components

Angular Component

The Angular setup consists of a file input within a form element, which triggers the file upload process. The key pieces of the Angular code include:

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

The submitUpload method in Angular captures file selection and submits the form.

NodeJS Web Backend

The backend is responsible for receiving the file and then forwarding it to the API. In the NodeJS web backend, we can see the relevant route to handle file uploads, which is configured to receive files.

The Solution

Sending Form Data with Pipe

The issue lies in how the NodeJS web backend forwards the file from the request to the API. To solve this, you need to use a pipe to send the data properly. Here’s the corrected code for your request:

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

Important Notes

No need for postReq.end(): After piping the form data to postReq, you do not need to call postReq.end(); this is handled automatically by the pipe method.

Debugging Uploads

If you want to further debug what is being sent to your API, you can write the form data to a file. This is very useful to ensure everything is working as intended:

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

When you check the contents of debug.log, you should see the structure of the form data being sent, which will look something like this:

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

Conclusion

By making simple adjustments to how you handle file uploads in your NodeJS web backend, specifically by using the pipe method, you can resolve issues related to empty file requests sent to your NodeJS API. With this solution, you're well on your way to successful file uploads from your Angular application to your backend!

Feel free to implement these changes and let us know how it works for you. Happy coding!