Store invoice source code instead of generate it everytime

apps/treasury/forms.py

@@ -28,7 +28,7 @@ class InvoiceForm(forms.ModelForm):
 
     class Meta:
         model = Invoice
-        exclude = ('bde', )
+        exclude = ('bde', 'tex', )
 
 
 class ProductForm(forms.ModelForm):

apps/treasury/models.py

@@ -6,6 +6,7 @@ from django.contrib.auth.models import User
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.db.models import Q
+from django.template.loader import render_to_string
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 from note.models import NoteSpecial, SpecialTransaction, MembershipTransaction
@@ -62,6 +63,34 @@ class Invoice(models.Model):
         verbose_name=_("Acquitted"),
     )
 
+    tex = models.TextField(
+        default="",
+        verbose_name=_("tex source"),
+    )
+
+    def save(self, *args, **kwargs):
+        """
+        When an invoice is generated, we store the tex source.
+        The advantage is to never change the template.
+        Warning: editing this model regenerate the tex source, so be careful.
+        """
+        products = self.products.all()
+
+        self.place = "Gif-sur-Yvette"
+        self.my_name = "BDE ENS Cachan"
+        self.my_address_street = "4 avenue des Sciences"
+        self.my_city = "91190 Gif-sur-Yvette"
+        self.bank_code = 30003
+        self.desk_code = 3894
+        self.account_number = 37280662
+        self.rib_key = 14
+        self.bic = "SOGEFRPP"
+
+        # Fill the template with the information
+        self.tex = render_to_string("treasury/invoice_sample.tex", dict(obj=self, products=products))
+
+        return super().save(*args, **kwargs)
+
     class Meta:
         verbose_name = _("invoice")
         verbose_name_plural = _("invoices")
@@ -75,6 +104,8 @@ class Product(models.Model):
     invoice = models.ForeignKey(
         Invoice,
         on_delete=models.PROTECT,
+        related_name="products",
+        verbose_name=_("invoice"),
     )
 
     designation = models.CharField(

apps/treasury/templatetags/escape_tex.py

@@ -13,6 +13,8 @@ def do_latex_escape(value):
         .replace("_", "\\_")
         .replace("{", "\\{")
         .replace("}", "\\}")
+        .replace("\n", "\\\\")
+        .replace("\r", "")
     )
 
 

apps/treasury/views.py

@@ -139,23 +139,7 @@ class InvoiceRenderView(LoginRequiredMixin, View):
     def get(self, request, **kwargs):
         pk = kwargs["pk"]
         invoice = Invoice.objects.filter(PermissionBackend.filter_queryset(request.user, Invoice, "view")).get(pk=pk)
-        products = Product.objects.filter(invoice=invoice).all()
-
-        invoice.place = "Gif-sur-Yvette"
-        invoice.my_name = "BDE ENS Cachan"
-        invoice.my_address_street = "4 avenue des Sciences"
-        invoice.my_city = "91190 Gif-sur-Yvette"
-        invoice.bank_code = 30003
-        invoice.desk_code = 3894
-        invoice.account_number = 37280662
-        invoice.rib_key = 14
-        invoice.bic = "SOGEFRPP"
-
-        # Replace line breaks with the LaTeX equivalent
-        invoice.description = invoice.description.replace("\r", "").replace("\n", "\\\\ ")
-        invoice.address = invoice.address.replace("\r", "").replace("\n", "\\\\ ")
-        # Fill the template with the information
-        tex = render_to_string("treasury/invoice_sample.tex", dict(obj=invoice, products=products))
+        tex = invoice.tex
 
         try:
             os.mkdir(BASE_DIR + "/tmp")