auto calculate total

pyinvoice/models.py

@@ -1,4 +1,5 @@
 from __future__ import unicode_literals
+from decimal import Decimal
 
 
 class PDFInfo(object):
@@ -55,22 +56,22 @@ class Item(object):
     """
     Product/Item information
     """
-    def __init__(self, item_id, name, description, units, unit_price, subtotal, vat_tax=None):
+    def __init__(self, name, description, units, unit_price):
         """
         Item modal init
-        :param item_id: Order id or Item id
         :param name: Item name
         :param units: Amount
         :param unit_price: Unit price
         :return:
         """
-        self.item_id = item_id
         self.name = name
         self.description = description
         self.units = units
         self.unit_price = unit_price
-        self.vat_tax = vat_tax
+
-        self.subtotal = subtotal
+    @property
+    def amount(self):
+        return int(self.units) * Decimal(self.unit_price)
 
 
 class Transaction(object):

pyinvoice/templates.py

@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 from datetime import datetime, date
+from decimal import Decimal
 from reportlab.lib import colors
 from reportlab.lib.enums import TA_CENTER, TA_RIGHT
 from reportlab.lib.pagesizes import letter
@@ -42,8 +43,7 @@ class SimpleInvoice(SimpleDocTemplate):
         self.client_info = None
         self.is_paid = False
         self._items = []
-        self.item_tax_total = None
+        self._item_tax_rate = None
-        self.item_total = None
         self._transactions = []
         self._story = []
 
@@ -55,6 +55,9 @@ class SimpleInvoice(SimpleDocTemplate):
         if isinstance(item, Item):
             self._items.append(item)
 
+    def set_item_tax_rate(self, rate):
+        self._item_tax_rate = rate
+
     @property
     def transactions(self):
         return self._transactions[:]
@@ -162,37 +165,65 @@ class SimpleInvoice(SimpleDocTemplate):
 
     def __build_items(self):
         # Items
-        item_data = [
+        item_data = []
-            (
+        item_subtotal = 0
-                item.item_id,
+
-                item.name,
+        for item in self._items:
-                Paragraph(item.description, self._defined_styles.get('TableParagraph')),
+            if not isinstance(item, Item):
-                item.units,
+                continue
-                item.unit_price,
+
-                item.vat_tax if item.vat_tax is not None else '-',
+            item_data.append(
-                item.subtotal
+                (
-            ) for item in self._items if isinstance(item, Item)
+                    item.name,
-        ]
+                    Paragraph(item.description, self._defined_styles.get('TableParagraph')),
+                    item.units,
+                    item.unit_price,
+                    item.amount
+                )
+            )
+            item_subtotal += item.amount
 
         if item_data:
             self._story.append(
                 Paragraph('Detail', self._defined_styles.get('Heading1'))
             )
-            item_data.insert(0, ('#', 'Name', 'Description', 'Units', 'Unit Price', 'Vat/Tax', 'Subtotal'))
+
-            if self.item_tax_total or self.item_total:
+            item_data_title = ('Name', 'Description', 'Units', 'Unit Price', 'Amount')
+            item_data.insert(0, item_data_title)  # Insert title
+
+            # Summary field
+            sum_start_y_index = len(item_data)
+            sum_end_x_index = -1 - 1
+            sum_start_x_index = len(item_data_title) - abs(sum_end_x_index)
+            style = []
+
+            # ##### Subtotal #####
+            item_data.append(
+                ('Subtotal', '', '', '', item_subtotal)
+            )
+
+            style.append(('SPAN', (0, sum_start_y_index), (sum_start_x_index, sum_start_y_index)))
+            style.append(('ALIGN', (0, sum_start_y_index), (sum_end_x_index, -1), 'RIGHT'))
+
+            # Tax total
+            if self._item_tax_rate is not None:
+                tax_total = item_subtotal * (Decimal(str(self._item_tax_rate)) / Decimal('100'))
                 item_data.append(
-                    (
+                    ('Vat/Tax ({0}%)'.format(self._item_tax_rate), '', '', '', tax_total)
-                        'Total', '', '', '', '',
-                        self.item_tax_total if self.item_tax_total else '-',
-                        self.item_total if self.item_total else '-'
-                    )
                 )
-                style = [
+                sum_start_y_index += 1
-                    ('SPAN', (0, len(item_data) - 1), (4, len(item_data) - 1)),
+                style.append(('SPAN', (0, sum_start_y_index), (sum_start_x_index, sum_start_y_index)))
-                    ('ALIGN', (0, len(item_data) - 1), (-3, -1), 'RIGHT'),
+                style.append(('ALIGN', (0, sum_start_y_index), (sum_end_x_index, -1), 'RIGHT'))
-                ]
             else:
-                style = None
+                tax_total = None
+
+            # Total
+            total = item_subtotal + tax_total if tax_total else Decimal('0')
+            item_data.append(('Total', '', '', '', total))
+            sum_start_y_index += 1
+            style.append(('SPAN', (0, sum_start_y_index), (sum_start_x_index, sum_start_y_index)))
+            style.append(('ALIGN', (0, sum_start_y_index), (sum_end_x_index, -1), 'RIGHT'))
+
             self._story.append(TableWithHeader(item_data, horizontal_align='LEFT', style=style))
 
     def __build_transactions(self):

simple.py

@@ -32,11 +32,10 @@ doc.client_info = ClientInfo(
     post_code='222222'
 )
 
-doc.add_item(Item('0000', 'Item', 'Item', 1, '1.1', '1.32', '0.22'))
+doc.add_item(Item('Item', 'Item desc', 1, '1.1'))
-doc.add_item(Item('1111', 'Item', 'Item', 2, '2.2', '4.4'))
+doc.add_item(Item('Item', 'Item desc', 2, '2.2'))
-doc.add_item(Item('2222', 'Item', 'Item', 3, '3.3', '9.9'))
+doc.add_item(Item('Item', 'Item desc', 3, '3.3'))
-doc.item_tax_total = Decimal('.22')
+doc.set_item_tax_rate(20)  # 20%
-doc.item_total = Decimal('16.2')
 
 doc.add_transaction(Transaction('Paypal', 111, datetime.now(), 1))
 doc.add_transaction(Transaction('Strip', 222, datetime.now(), 2))