Display total amount preview. Close #2

src/purchase/forms.py

@@ -2,6 +2,7 @@ from crispy_forms.bootstrap import InlineRadios
 from crispy_forms.helper import FormHelper
 from crispy_forms.layout import Div, Layout, Submit
 from django import forms
+from django.urls import reverse
 from django.utils.translation import gettext as _
 
 from purchase.layout import BasketItemField
@@ -25,6 +26,12 @@ class BasketForm(forms.ModelForm):
         self.helper = FormHelper()
         self.helper.form_class = "form-horizontal"
         self.helper.add_input(Submit("submit", _("Save")))
+        self.helper.attrs = {
+            "hx_post": reverse("purchase:price_preview"),
+            "hx_trigger": "change",
+            "hx_target": "#price_preview",
+            "hx_swap": "innerHTML",
+        }
         self.helper.layout = Layout()
         products = {}
         basket = kwargs.get("instance")
@@ -51,6 +58,7 @@ class BasketForm(forms.ModelForm):
                 css_id="products",
             ),
             InlineRadios("payment_method"),
+            Div(css_id="price_preview", css_class="mb-2"),
         )
 
     def save(self):

src/purchase/static/purchase/js/basket_form.js

@@ -1,14 +1,25 @@
 window.incrementValue = function (id) {
-    let value = parseInt(document.getElementById(id).value);
+    const element = document.getElementById(id);
+    let value = parseInt(element.value);
     value = isNaN(value) ? 0 : value;
     value++;
-    document.getElementById(id).value = value;
+    element.value = value;
+
+    window.dispatchChanged(element);
 };
 
 window.decrementValue = function (id) {
-    let value = parseInt(document.getElementById(id).value);
+    const element = document.getElementById(id);
+    let value = parseInt(element.value);
     value = isNaN(value) ? 0 : value;
     value--;
     value = value < 0 ? 0 : value;
-    document.getElementById(id).value = value;
+    element.value = value;
+
+    window.dispatchChanged(element);
+};
+
+window.dispatchChanged = function (element) {
+    const event = new Event("change", { bubbles: true });
+    element.dispatchEvent(event);
 };

src/purchase/urls.py

@@ -1,12 +1,19 @@
 from django.urls import path
 
-from purchase.views import delete_basket, list_baskets, new_basket, update_basket
-from purchase.views.basket import additional_unpriced_product
+from purchase.views import (
+    additional_unpriced_product,
+    delete_basket,
+    list_baskets,
+    new_basket,
+    price_preview,
+    update_basket,
+)
 from purchase.views.reports import by_hour_plot_view, products_plots_view, reports
 
 app_name = "purchase"
 urlpatterns = [
     path("", list_baskets, name="list"),
+    path("price_preview/", price_preview, name="price_preview"),
     path("new/", new_basket, name="new"),
     path("<int:pk>/update/", update_basket, name="update"),
     path("<int:pk>/delete/", delete_basket, name="delete"),

src/purchase/views/__init__.py

@@ -1,3 +1,17 @@
-from .basket import delete_basket, list_baskets, new_basket, update_basket
+from .basket import (
+    additional_unpriced_product,
+    delete_basket,
+    list_baskets,
+    new_basket,
+    price_preview,
+    update_basket,
+)
 
-__all__ = ["new_basket", "update_basket", "delete_basket", "list_baskets"]
+__all__ = [
+    "new_basket",
+    "update_basket",
+    "delete_basket",
+    "list_baskets",
+    "additional_unpriced_product",
+    "price_preview",
+]

src/purchase/views/basket.py

@@ -3,7 +3,7 @@ import logging
 from django.contrib import messages
 from django.contrib.auth.decorators import permission_required
 from django.core.handlers.wsgi import WSGIRequest
-from django.http import HttpRequest, HttpResponse
+from django.http import HttpResponse
 from django.shortcuts import get_object_or_404, redirect, render
 from django.template.response import TemplateResponse
 from django.urls import reverse
@@ -12,7 +12,7 @@ from django.utils.translation import gettext_lazy as _
 from django.views.decorators.http import condition, require_http_methods
 from django_htmx.http import trigger_client_event
 
-from purchase.forms import UNPRICED_PREFIX, BasketForm
+from purchase.forms import PRICED_PREFIX, UNPRICED_PREFIX, BasketForm
 from purchase.models import Basket, Product, reports_etag, reports_last_modified
 
 logger = logging.getLogger(__name__)
@@ -100,14 +100,14 @@ def additional_unpriced_product(request: WSGIRequest) -> HttpResponse:
 
 @permission_required("purchase.view_basket")
 @condition(etag_func=reports_etag, last_modified_func=reports_last_modified)
-def list_baskets(request: HttpRequest) -> HttpResponse:
+def list_baskets(request: WSGIRequest) -> HttpResponse:
     context = {"baskets": Basket.objects.priced().order_by("-id")}
     return TemplateResponse(request, "purchase/basket_list.html", context)
 
 
 @require_http_methods(["GET", "POST"])
 @permission_required("purchase.delete_basket")
-def delete_basket(request: HttpRequest, pk: int) -> HttpResponse:
+def delete_basket(request: WSGIRequest, pk: int) -> HttpResponse:
     basket = get_object_or_404(Basket, pk=pk)
     if request.method == "GET":
         context = {"basket": basket}
@@ -115,3 +115,18 @@ def delete_basket(request: HttpRequest, pk: int) -> HttpResponse:
     basket.delete()
     messages.success(request, _("Basket successfully deleted."))
     return redirect("purchase:list")
+
+
+@require_http_methods(["POST"])
+@permission_required("purchase.add_basket")
+def price_preview(request: WSGIRequest) -> HttpResponse:
+    total = 0
+    for name in request.POST:
+        if name.startswith(PRICED_PREFIX):
+            product_id = name[len(PRICED_PREFIX) :]
+            product = get_object_or_404(Product, pk=product_id)
+            total += product.unit_price_cents * int(request.POST.get(name, 0))
+        elif name.startswith(UNPRICED_PREFIX):
+            total += sum(map(int, request.POST.getlist(name)))
+
+    return HttpResponse(f"Montant total : {total/100:.2f}€")