FAQs
This section answers common questions developers may encounter while integrating and customizing the Powerful File Uploader with Dropzone. If you're running into unexpected behavior, layout issues, or file handling limitations, the answers below will likely help you resolve them quickly.
1. Why is my entire app rendering blank after adding the uploader?
By default, the component is inserted with an expansion setting of "Expanded", which can break your layout if placed inside a parent that doesn't allow expanded children
✅ Solution: Select the inserted component and change the expansion setting to "Default". This should fix the blank screen and render your app as expected.
2. Why doesn’t the uploaded file (bytes) get stored along with the rest of the file metadata?
To ensure maximum performance and memory efficiency, especially when handling large files, the component does not store the actual file (bytes) in the AppState. Only metadata like file name, size, and temporary URL (tempUrl) are stored.
If you wish to manually manage and store the full file object (including the bytes), you can enable the userHandleUploadExternally parameter and handle the uploaded file yourself inside the custom action, storing it in a Page State or sending it directly to a backend or storage service. Read more.
3. How can I hide the file list but still keep the uploaded files in AppState?
If you want to build your own custom layout for previewing files (like a custom image grid) without handling the logic of file uploads manually, simply leave the fileInListComponent parameter empty.
This will:
Prevent the default file list from rendering.
Still store the uploaded file metadata in the AppState under
receivedFilesInfo, so you can use them in your layout.
4. How do I limit the number of characters shown in file names?
The built-in file list component (fileInListComponent) includes a parameter called maxCharacters. This allows you to set the maximum number of characters to display for each file name.
The file extension (e.g. .pdf, .jpg) is always preserved and shown, even if the file name is truncated. This keeps your UI clean and avoids very tall list items caused by long file names.
5. Why doesn’t Android show a prompt to choose between Camera and Gallery?
On Android, users can access all files — including photos taken with the camera — directly from the file explorer. For this reason, the uploader skips the extra step of prompting for source selection, reducing user effort.
If a user wants to upload a photo:
They simply take it using their camera.
Then select it from the file explorer, where it will appear under "Camera" or "DCIM".
This is different from iOS, where files captured by the camera are not easily accessible in the file explorer, making source selection dialogs more useful there.
6. Why do some of my download links fail even though the URLs are correct?
This is often caused by CORS (Cross-Origin Resource Sharing) restrictions on the server hosting the file. If the server does not explicitly allow your app’s origin to access the file, the download request will fail.
🛠 How to check:
Open the browser developer tools.
Go to the "Network" tab.
Enable the "Fetch/XHR" filter.
Try downloading the file again.
You will likely see the file in the list with a "CORS error".
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