Allow counter to start from an offset

Signed-off-by: DL6ER <[email protected]>

Author: DL6ER

README.md

@@ -98,7 +98,7 @@ Additional printer support comes from [matmair/brother_ql-inventree](https://git
 
 ### Supported templates
 
--   `{{counter}}` — Inserts the current counter value (automatically increments when printing multiple labels at the same time).
+-   `{{counter[:start]}}` — Inserts the current counter value (automatically increments when printing multiple labels at the same time).
 -   `{{datetime:<format>}}` — Inserts the current date and time, e.g. `%H:%M:%S %d.%m.%Y` (see [strftime](https://strftime.org/)).
 -   `{{uuid}}` — Inserts a random UUID (Universally Unique Identifier).
 -   `{{short-uuid}}` — Inserts a shortened version of a UUID.

app/labeldesigner/label.py

@@ -92,7 +92,7 @@ def __init__(
             border_distance=(0, 0),
             border_color=(0, 0, 0),
             timestamp=0,
-            counter=1,
+            counter=0,
             red_support=False):
         self._width = width
         self._height = height
@@ -128,7 +128,7 @@ def want_text(self, img):
         # We always want to draw text (even when empty) when no image is
         # provided to avoid an error 500 because we created no image at all
         return img is None or self._label_content not in (LabelContent.QRCODE_ONLY,) and len(self.text) > 0 and len(self.text[0]['text']) > 0
-    
+
     @property
     def need_image_text_distance(self):
         return self._label_content in (LabelContent.TEXT_QRCODE,
@@ -173,16 +173,17 @@ def label_type(self, value):
         self._label_type = value
 
     def process_templates(self):
-        # Loop over text lines and replace
-        # {{datetime:x}} by current datetime in specified format x
-        # {{counter}} by an incrementing counter
+        # Loop over text lines and replace templates
         self.text = self.input_text.copy()
         for line in self.text:
             if len(line['text']) > 500:
                 logger.warning("Text line is very long (> 500 characters), this may lead to long processing times.")
 
-            # Replace {{counter}} with current counter value
-            line['text'] = line['text'].replace("{{counter}}", str(self._counter))
+            # Replace {{counter[:offset]}} with current label counter (x is an optional offset defaulting to 1)
+            def counter_replacer(match):
+                offset = int(match.group(1)) if match.group(1) else 1
+                return str(self._counter + offset)
+            line['text'] = re.sub(r"\{\{counter(?:\:(\d+))?\}\}", counter_replacer, line['text'])
 
             # Replace {{datetime:x}} with current datetime formatted as x
             def datetime_replacer(match):

app/labeldesigner/routes.py

@@ -128,7 +128,7 @@ def print_label():
 
     try:
         for i in range(print_count):
-            label = create_label_from_request(request, i + 1)
+            label = create_label_from_request(request, i)
             # Cut only if we
             # - always cut, or
             # - we cut only once and this is the last label to be generated
@@ -164,7 +164,7 @@ def parse_text_form(input):
         return []
     return json.loads(input)
 
-def create_label_from_request(request, counter: int = 1):
+def create_label_from_request(request, counter: int = 0):
     d=request.values
     label_size = d.get('label_size', "62")
     kind = [label.form_factor for label in ALL_LABELS if label.identifier == label_size][0]

app/labeldesigner/templates/labeldesigner.html

@@ -356,7 +356,8 @@ <h6>Additional Font Options:</h6>
                             <li><code>{{'{{datetime:%H:%M:%S %d.%m.%Y'}}}}</code> — Inserts the current date and time when printing.
                                 You can customize the format using <a href="https://strftime.org/" target="_blank"
                                     rel="noopener">strftime</a> options.</li>
-                            <li><code>{{'{{counter'}}}}</code> — Inserts an up-counting number, increasing for every printed label.
+                            <li><code>{{'{{counter[:start]}}'}}</code> — Inserts an up-counting number. You can optionally specify a <code>start</code> value (defaulting to 1) to start counting from a different number.
+                                When printing multiple labels at once, the counter automatically increments for each label.
                             </li>
                             <li><code>{{'{{uuid'}}}}</code> — Inserts a random UUID (Universally Unique Identifier).</li>
                             <li><code>{{'{{short-uuid'}}}}</code> — Inserts a shortened version of a UUID.</li>

tests/template.png

@@ -392,7 +392,7 @@ def test_generate_template(client):
         {
             'family': 'DejaVu Sans',
             'style': 'Book',
-            'text': '{{datetime:%d.%m.%Y %H:%M:%S}} COUNTER: {{counter}}',
+            'text': '{{datetime:%d.%m.%Y %H:%M:%S}} COUNTER: {{counter}} {{counter:5}}',
             'size': '30',
             'align': 'left'
         },