Скачать или смотреть Why You Can't Set an Image src Dynamically After Component is Mounted in React

Discover why dynamically setting an image source in React can be problematic and learn how to properly handle image paths using Webpack's `require`.
---
This video is based on the question https://stackoverflow.com/q/63104575/ asked by the user 'Brand New' ( https://stackoverflow.com/u/9309517/ ) and on the answer https://stackoverflow.com/a/63104747/ provided by the user 'Helix' ( https://stackoverflow.com/u/11307217/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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: Why I can't set an image src dynamically after component is mounted?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Problem: Dynamic Image Sources in React

When building React components, you may run into an issue trying to set an image source (src) dynamically after the component has mounted. For instance, you might retrieve an image path from a database, but it doesn't display as expected. Instead, it works fine when using a hard-coded path. Why is this happening? Let's explore this challenge and find a solution.

The Heart of the Issue

In React, when we fetch or dynamically create paths for images, the require() function faces a limitation— fully dynamic paths aren't supported. This means Webpack requires a static path to understand where your image assets are located during the building process. The dynamic path you've tried to set is literally ‘dynamic’, which prevents Webpack from being able to reference it correctly.

A Common Example

Here's a scenario we've encountered:

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

In this code, even though response.data returns a valid path (e.g., images/img1.jpg), using it in a require() statement fails since Webpack cannot determine where to find the image asset.

The Solution: Modify the Approach

To effectively handle dynamic paths in React components, you need to make some adjustments. Let’s break down the required changes step-by-step.

1. Storing the Image Name

Instead of managing the full path directly, store just the image name in the component’s state. This way you maintain a clearer and more manageable structure, as shown below:

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

With the name state variable, you retain only the image file's name without worrying about the preceding directory paths.

2. Fetch and Set the Image Name

When you make the axios request, split the response.data to extract and store the image file name. Here's the revamped useEffect hook:

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

Notice here how the path is split with .pop() to only get the last part, which corresponds to the image name (e.g. img1.jpg).

3. Render the Image

Finally, update the return statement of your component to set the src with the statically defined path, concatenated with the dynamically acquired name of the image. This ensures Webpack knows where to look when rendering the image:

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

By using a static base path together with the dynamic name, you achieve a functional solution that adheres to Webpack’s requirements.

Conclusion

In summary, dynamically setting image sources in React requires understanding Webpack's static path constraints. By adjusting your approach to only use the necessary part of the image path, you can successfully render your images without error.

This method increases flexibility while still complying with Webpack’s asset management rules, allowing your applications to remain robust and reliable.

Implement this solution in your React components and watch your images load seamlessly even after component mounting!