Restrict file size Lightning file upload?

Question

I have a Lightning file Upload component I am using Lightning:fileupload . so user tries to upload more than 100MB. I want to show an error message, it is possible?

Answer 1

I can't see such a feature being supported out of the box looking at the specifications for Aura File Upload. The supported attributes are:

• accept
• body
• class
• disabled
• label
• multiple
• name
• onuploadfinished
• recordId
• title

Answer 2

I had a similar requirement but using LWC and what I did was, allowed the User to upload the 100MB file but then check the document size, if it was greater than XXX MB, I deleted the file and showed an error message.

Example code:

HTML:

<lightning-file-upload label="" onuploadfinished={uploadFile}
                                            </lightning-file-upload>

JS:

    async handleUpload(event) {
    const fileUploaded = event.detail.files;
    try {
            const file = fileUploaded[0];

            const checkDocSize = await getDocumentSize({docId : file.documentId});

            if(checkDocSize == true) {
                const toastEvent = new ShowToastEvent({
                    message: 'File cannot be uploaded as it exceeds the maximum size of 5MB',
                    variant: 'error'
                });
                this.dispatchEvent(toastEvent);
                const docDeleted = await deleteDocument({fileId : file.documentId});
            }
            else {
                const toastEvent = new ShowToastEvent({
                    message: 'File uploaded successfully',
                    variant: 'success'
                });
            }
    } catch(e) {
        console.error('Error during file upload:',error);
    }
}

Apex:

    @AuraEnabled
public static Boolean getDocumentSize(String docId) {
    List<ContentDocument> documentList = [SELECT Id, Title, ContentSize FROM ContentDocument WHERE Id = :docId WITH SECURITY_ENFORCED];
    Boolean sizeExceeded = false;

    try{
        if(!documentList.isEmpty()) {
            Decimal contentSize = documentList[0].ContentSize;
            Decimal fileSize = (contentSize / (1024.0*1024.0)).setScale(2);
            if(fileSize > 5 ) {
                return true;
            }
            return false;
        }
    } catch(Exception e){
        throw new AuraHandledException(e.getMessage());
    }
}
    @AuraEnabled
public static void deleteDocument(String docId) {
    List<ContentDocument> docToBeDeleted = [SELECT Id FROM ContentDocument WHERE Id = :docId];
    
    try{
        if(!docToBeDeleted.isEmpty()) {
            delete docToBeDeleted;
        }
    } catch(Exception e){
        throw new AuraHandledException(e.getMessage());
    }
}