Django rest framework PDF creation and email via gmail SMTP and reportLab

In this blog we create PDF using Report Lab and email it to the user using gmail SMTP service. All actions are performed in Django.

Overview

Ever wanted to send email with attachements that too in django? And have the attachments created from the user input? This post tries to solve exactly that.

Main steps

In this blog we create PDF using Report Lab and email it to the user using gmail SMTP service. All actions are performed in Django.

Step 1 : create django view to serialize data

To begin with, we create a view CreatePDF which accepts POST request and the data gets passed onto CreatePDFSerializer which serializes our data and validates it. If our data is valid, we generate PDF using generate_pdf function and email to the recipent (emailaddress of the users) using the sendPDF function. If everything does not execute properly, we return an error response else a success.

The local variable myresponse is a dictionary which helps us manage the response for each return statement in the correct format as expected by response method.

SUCCESS = 'success'
ERROR = 'error'
message_list = ['response', 'status', 'message'] # eg: ["success", 201, "successfully upload the file"]

@csrf_exempt
@api_view(['POST',])
def CreatePDF(request):
    myresponse = {k: [] for k in message_list}

    try:
        myData = request.data
        # serialier the data
        serializer = serializers.CreatePDFSerializer(data=myData)  
        if serializer.is_valid():
            try:
                sendPDF(**myData.dict())  # create pdf and send email
            except Exception as e:
                RequestResponse(
                    myresponse,
                    ERROR,
                    status.HTTP_400_BAD_REQUEST,
                    {"Email": ["Could not send mail!"]},
                )
                return Response(data=myresponse)
            
            account = serializer.save()
            RequestResponse(
                myresponse,
                SUCCESS,
                status.HTTP_201_CREATED,
                {"Success": [f"Inspection Report e-mailed to {account.EmailAddress}!"]},
            )
            return Response(data=myresponse)

        RequestResponse(
            myresponse, ERROR, status.HTTP_400_BAD_REQUEST, serializer.errors
        )
        return Response(data=myresponse)
    
    except Exception as e:
        print(e)
        RequestResponse(
            myresponse,
            ERROR,
            status.HTTP_500_INTERNAL_SERVER_ERROR,
            {"Error": ["Internal Server Error"]},
        )
        return Response(data=myresponse)

step 2: Generate PDF using Report Lab

In views.py we create a function to generate pdf using Report Lab package. This allows us to define the page size and line strings with text placement to be included.

def generate_pdf(**Mydata):
    y = 700
    buffer = io.BytesIO()  # in memory create pdf
    p = canvas.Canvas(buffer, pagesize=letter)
    p.setFont('Helvetica', 14)
    p.drawString(220, y, Mydata['Title'])
    p.drawString(450, y, 'Date:' + timezone.now().strftime('%Y-%b-%d'))
    p.line(30, 675, 550, 675)
    p.drawString(220, y - 300, 'Time'
                 + str(Mydata['time']))
    p.showPage()
    p.save()
    pdf = buffer.getvalue()
    buffer.close()
    return pdf

step 3: Send Email via SMTP backend

In views.py, we create sendPDF function which calls the generate_pdfto generate PDF and attaches the pdf to the email using the EmailMessage class method attach. We additionally need to setup backend for smtp service and host user which is to be done in settings.py.

# views.py
def sendPDF(**Mydata):
    pdf = generate_pdf(**Mydata)
    msg = EmailMessage(Mydata['Title'], " Your Report is ready! ", settings.EMAIL_HOST_USER, to=[Mydata['EmailAddress']])
    msg.attach(f"{Mydata['Title']}.pdf", pdf, 'application/pdf')
    msg.content_subtype = "html"
    resp = msg.send()
    print("resp:" , resp)

In settings.py

# settings.py
EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST = "smtp.gmail.com"
EMAIL_HOST_USER = 'your_email@gmail.com'
EMAIL_HOST_PASSWORD = 'your_password'
EMAIL_PORT = 587
EMAIL_USE_TLS = True

At this point we have been able to successfully setup and send email with attachment.