Document Review System in Django and React

To implement a document review feature with versioning in your Django and React application, you'll need to set up proper URL routing, file storage, and version tracking. Here's how you can approach this:

Django Implementation

First, create a model to store your documents and their revisions:

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# models.py
from django.db import models

class Document(models.Model):
    name = models.CharField(max_length=255)
    file_path = models.CharField(max_length=255)
    created_at = models.DateTimeField(auto_now_add=True)
    
class DocumentRevision(models.Model):
    document = models.ForeignKey(Document, related_name='revisions', on_delete=models.CASCADE)
    file = models.FileField(upload_to='documents/')
    revision_number = models.IntegerField()
    created_at = models.DateTimeField(auto_now_add=True)
    
    class Meta:
        unique_together = ('document', 'revision_number')

Then, set up your URL patterns:

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# urls.py
from django.urls import path
from . import views

urlpatterns = [
    path('doc/review/<str:document_name>', views.document_view, name='document_view'),
]

Implement the view to handle document retrieval with optional revision parameter:

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# views.py
from django.http import FileResponse, Http404
from django.shortcuts import get_object_or_404
from .models import Document, DocumentRevision

def document_view(request, document_name):
    document = get_object_or_404(Document, name=document_name)
    
    # Check if a specific revision was requested
    revision_number = request.GET.get('revision', None)
    
    if revision_number is not None:
        # Get specific revision
        try:
            revision = DocumentRevision.objects.get(
                document=document, 
                revision_number=int(revision_number)
            )
        except (DocumentRevision.DoesNotExist, ValueError):
            raise Http404("Document revision not found")
    else:
        # Get latest revision
        revision = DocumentRevision.objects.filter(
            document=document
        ).order_by('-revision_number').first()
        
        if not revision:
            raise Http404("No revisions found for this document")
    
    # Return the file
    return FileResponse(revision.file.open('rb'), content_type='application/pdf')

For file uploads, create an API endpoint:

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# views.py (continued)
from rest_framework.decorators import api_view
from rest_framework.response import Response
from rest_framework import status

@api_view(['POST'])
def upload_document(request):
    file = request.FILES.get('file')
    document_name = request.data.get('name')
    
    if not file or not document_name:
        return Response(
            {"error": "Both file and name are required"}, 
            status=status.HTTP_400_BAD_REQUEST
        )
    
    # Get or create document
    document, created = Document.objects.get_or_create(
        name=document_name,
        defaults={'file_path': f'documents/{document_name}'}
    )
    
    # Determine revision number
    if created:
        revision_number = 0
    else:
        latest_revision = DocumentRevision.objects.filter(
            document=document
        ).order_by('-revision_number').first()
        
        revision_number = latest_revision.revision_number + 1 if latest_revision else 0
    
    # Create new revision
    DocumentRevision.objects.create(
        document=document,
        file=file,
        revision_number=revision_number
    )
    
    return Response({
        "success": True,
        "document_name": document_name,
        "revision": revision_number,
        "url": f"/doc/review/{document_name}"
    })

Don't forget to add the upload URL:

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# urls.py (updated)
urlpatterns = [
    path('doc/review/<str:document_name>', views.document_view, name='document_view'),
    path('api/documents/upload/', views.upload_document, name='upload_document'),
]

This implementation will allow you to:

1. Upload documents with a specific name
2. Access the latest version at /doc/review/blabla.pdf
3. Access specific revisions at /doc/review/blabla.pdf?revision=0

Make sure to configure your Django settings properly for file storage and to include these URLs in your main URL configuration.