In views.py, I have a view that displays invoice information to the user, and a button for creating a batch payment file. When the button is clicked, a CSV template file is read, and a new CSV is created from that template with updated with data from the database, and then downloaded directly to the browser.
At the same time, I want to return some context to generate toast notifications about the processing status, return error messages, etc. It seems I need to do this via multiple HTTP requests/responses, and I'm not sure how to go about it.
Here's the view:
class InvoiceView(TemplateView):
model = Cost
template_name = "pipeline/invoices_list.html"
costs = Cost.objects.all()
def get_context_data(self, **kwargs):
# some context data
return context
def post(self, request, *args, **kwargs):
if "batch-pay-csv" in request.POST:
response, batch_payment_status = create_batch_payment_template(self.costs)
context = self.get_context_data(**kwargs)
context['batch_payment_status'] = batch_payment_status
return response
and an abbreviated version of the create_batch_payment_file() function (in utils.py):
def create_batch_payment_file(costs):
'''
Create a batch payment file from the template in /static.
'''
invoices = costs.filter(invoice_status__in=["REC", "REC2"])
processing_status = {} # format: invoice PO number {status (success/error), message}
response = HttpResponse(
content_type='text/csv',
headers = {'Content-Disposition': 'attachment; filename = "WISE_BATCH_PAYMENT.csv"'},
)
# for invoice in invoices, write stuff to the CSV
context = processing_status
return response, context
I'm starting to think it would be easier to generate a download button on the template rather than try to automatically download it to the browser, but would love to hear any ideas.
Figured it out! Instead of using it as a utility function, I turned it into a view in views.py so I could call it with AJAX, and passed the data dict into the headers of the HttpResponse object.
def create_batch_payment_file(request):
'''
Create a batch payment file from the template in /static.
'''
invoices = Cost.objects.filter(invoice_status__in=["REC", "REC2"])
processing_status = {} # format: invoice PO number {status (success/error), message}
response = HttpResponse(
content_type='text/csv',
headers = {'Content-Disposition': 'attachment; filename = "WISE_BATCH_PAYMENT.csv"'},
)
# for invoice in invoices, write stuff to the CSV
data = processing_status
response['X-Processing-Status'] = json.dumps(data)
return response
Then on the client side, made an AJAX call:
$("#batch-payment-create").on("submit", function(e) {
e.preventDefault()
const csrftoken = document.querySelector('[name=csrfmiddlewaretoken]').value;
$.ajax({
headers: { 'X-CSRFToken': csrftoken },
type: "POST",
url: "/myapp/myview/",
data: "",
success: function(data, testStatus, xhr) {
var blob = new Blob([data]);
var link = document.createElement('a');
var processing_status = xhr.getResponseHeader('X-Processing-Status');
console.log('Processing status:', processing_status);
link.href = window.URL.createObjectURL(blob);
link.download = "WISE_batch_payment.csv";
link.click();
}
})
})
Hopefully this helps someone else!