def get_interactive_withdraw(request: Request) -> Response:
"""
GET /transactions/withdraw/webapp
This endpoint retrieves the next form to be served to the user in the
interactive flow. The following steps are taken during this process:
1. URL arguments are parsed and validated.
2. interactive_url() is called to determine whether or not the anchor
uses an external service for the interactive flow. If a URL is
returned, this function redirects to the URL. However, the session
cookie should still be included in the response so future calls to
GET /transactions/withdraw/interactive/complete are authenticated.
3. form_for_transaction() is called to retrieve the next form to
render to the user.
4. get and post URLs are constructed with the appropriate arguments
and passed to the response to be rendered to the user.
"""
args_or_error = interactive_args_validation(request)
if "error" in args_or_error:
return args_or_error["error"]
transaction = args_or_error["transaction"]
asset = args_or_error["asset"]
callback = args_or_error["callback"]
amount = args_or_error["amount"]
url = rwi.interactive_url(request, transaction, asset, amount, callback)
if url: # The anchor uses a standalone interactive flow
return redirect(url)
form = rwi.form_for_transaction(transaction, amount=amount)
content = rwi.content_for_template(Template.WITHDRAW,
form=form,
transaction=transaction)
if not (form or content):
logger.error(
"The anchor did not provide content, unable to serve page.")
if transaction.status != transaction.STATUS.incomplete:
return render_error_response(
_("The anchor did not provide content, is the interactive flow already complete?"
),
status_code=422,
content_type="text/html",
)
return render_error_response(
_("The anchor did not provide content, unable to serve page."),
status_code=500,
content_type="text/html",
)
elif content is None:
content = {}
if form:
scripts = registered_scripts_func({"form": form, **content})
else:
scripts = registered_scripts_func(content)
url_args = {"transaction_id": transaction.id, "asset_code": asset.code}
if callback:
url_args["callback"] = callback
if amount:
url_args["amount"] = amount
post_url = f"{reverse('post_interactive_withdraw')}?{urlencode(url_args)}"
get_url = f"{reverse('get_interactive_withdraw')}?{urlencode(url_args)}"
content.update(
form=form,
post_url=post_url,
get_url=get_url,
scripts=scripts,
operation=settings.OPERATION_WITHDRAWAL,
asset=asset,
use_fee_endpoint=registered_fee_func != calculate_fee,
)
return Response(content, template_name="withdraw/form.html")
def post_interactive_withdraw(request: Request) -> Response:
"""
POST /transactions/withdraw/webapp
This endpoint processes form submissions during the withdraw interactive
flow. The following steps are taken during this process:
1. URL arguments are parsed and validated.
2. form_for_transaction() is called to retrieve the form used to
submit this request. This function is implemented by the anchor.
3. The form is used to validate the data submitted, and if the form
is a TransactionForm, the fee for the transaction is calculated.
4. after_form_validation() is called to allow the anchor to process
the data submitted. This function should change the application
state such that the next call to form_for_transaction() returns
the next form in the flow.
5. form_for_transaction() is called again to retrieve the next
form to be served to the user. If a form is returned, the
function redirects to GET /transaction/withdraw/webapp. Otherwise,
The user's session is invalidated, the transaction status is
updated, and the function redirects to GET /more_info.
"""
args_or_error = interactive_args_validation(request,
Transaction.KIND.withdrawal)
if "error" in args_or_error:
return args_or_error["error"]
transaction = args_or_error["transaction"]
asset = args_or_error["asset"]
callback = args_or_error["callback"]
amount = args_or_error["amount"]
form = rwi.form_for_transaction(transaction, post_data=request.data)
if not form:
logger.error("Initial form_for_transaction() call returned None "
f"for {transaction.id}")
if transaction.status != transaction.STATUS.incomplete:
return render_error_response(
_("The anchor did not provide content, is the interactive flow already complete?"
),
status_code=422,
content_type="text/html",
)
return render_error_response(
_("The anchor did not provide content, unable to serve page."),
status_code=500,
content_type="text/html",
)
if not form.is_bound:
# The anchor must initialize the form with request.data
logger.error(
"form returned was not initialized with POST data, returning 500")
return render_error_response(
_("Unable to validate form submission."),
status_code=500,
content_type="text/html",
)
elif form.is_valid():
if issubclass(form.__class__, TransactionForm):
transaction.amount_in = form.cleaned_data["amount"]
transaction.save()
rwi.after_form_validation(form, transaction)
next_form = rwi.form_for_transaction(transaction)
if next_form or rwi.content_for_template(
Template.WITHDRAW, form=next_form, transaction=transaction):
args = {"transaction_id": transaction.id, "asset_code": asset.code}
if amount:
args["amount"] = amount
if callback:
args["callback"] = callback
url = reverse("get_interactive_withdraw")
return redirect(f"{url}?{urlencode(args)}")
else: # Last form has been submitted
logger.info(
f"Finished data collection and processing for transaction {transaction.id}"
)
invalidate_session(request)
# ensure all changes from `after_form_validation()` have been saved to the db
transaction.refresh_from_db()
# Add memo now that interactive flow is complete
#
# We use the transaction ID as a memo on the Stellar transaction for the
# payment in the withdrawal. This lets us identify that as uniquely
# corresponding to this `Transaction` in the database. But a UUID4 is a 32
# character hex string, while the Stellar HashMemo requires a 64 character
# hex-encoded (32 byte) string. So, we zero-pad the ID to create an
# appropriately sized string for the `HashMemo`.
transaction_id_hex = transaction.id.hex
padded_hex_memo = "0" * (
64 - len(transaction_id_hex)) + transaction_id_hex
transaction.memo = memo_hex_to_base64(padded_hex_memo)
if transaction.status != transaction.STATUS.pending_anchor:
transaction.status = Transaction.STATUS.pending_user_transfer_start
else:
logger.info(
f"Transaction {transaction.id} is pending KYC approval")
transaction.save()
args = {"id": transaction.id, "initialLoad": "true"}
if callback:
args["callback"] = callback
return redirect(f"{reverse('more_info')}?{urlencode(args)}")
else:
content = (rwi.content_for_template(
Template.WITHDRAW, form=form, transaction=transaction) or {})
if registered_scripts_func is not scripts:
logger.warning(
"DEPRECATED: the `scripts` Polaris integration function will be "
"removed in Polaris 2.0 in favor of allowing the anchor to override "
"and extend Polaris' Django templates. See the Template Extensions "
"documentation for more information.")
template_scripts = registered_scripts_func({"form": form, **content})
url_args = {"transaction_id": transaction.id, "asset_code": asset.code}
if callback:
url_args["callback"] = callback
if amount:
url_args["amount"] = amount
toml_data = registered_toml_func()
post_url = f"{reverse('post_interactive_withdraw')}?{urlencode(url_args)}"
get_url = f"{reverse('get_interactive_withdraw')}?{urlencode(url_args)}"
content.update(
form=form,
post_url=post_url,
get_url=get_url,
scripts=template_scripts,
operation=settings.OPERATION_WITHDRAWAL,
asset=asset,
use_fee_endpoint=registered_fee_func != calculate_fee,
org_logo_url=toml_data.get("DOCUMENTATION", {}).get("ORG_LOGO"),
)
return Response(content,
template_name="polaris/withdraw.html",
status=400)