Add util function to generate qr code for url

Author: johannaengland

changelog.d/2887.added.md

@@ -0,0 +1 @@
+Add functionality to create QR codes to a given url

python/nav/web/seeddb/utils/generate_qr_code.py

@@ -0,0 +1,55 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2024 Sikt
+#
+# This file is part of Network Administration Visualized (NAV).
+#
+# NAV is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License version 3 as published by the Free
+# Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.  You should have received a copy of the GNU General Public License
+# along with NAV. If not, see <http://www.gnu.org/licenses/>.
+#
+
+import base64
+import io
+import os
+
+import nav.web
+
+import qrcode
+from PIL import ImageDraw, ImageFont
+
+
+def generate_qr_code(url: str, name: str = "") -> str:
+    """
+    Generate a QR code from a given url, and, if given, adds the name below as a
+    caption
+
+    Returns the generated image as a byte string
+    """
+    # Creating QR code
+    qr = qrcode.QRCode(box_size=20)
+    qr.add_data(url)
+    img = qr.make_image()
+    draw = ImageDraw.Draw(img)
+
+    # Adding the name as caption
+    if name:
+        W, H = img.size
+        font_dir = os.path.dirname(nav.web.__file__)
+        font = ImageFont.truetype(os.path.join(font_dir, "static/fonts/OS600.woff"), 50)
+        w = font.getlength(name)
+        draw.text(((W - w) / 2, H * 0.9), text=name, font=font, fill="black")
+
+    # Turning image into byte string
+    data = io.BytesIO()
+    img.save(data, "JPEG")
+    encoded_img_data = base64.b64encode(data.getvalue())
+    out = encoded_img_data.decode('utf-8')
+
+    return out

requirements/base.txt

@@ -9,7 +9,9 @@ pyaml
 twisted~=23.8.0  # last version that still supports Python 3.7
 
 networkx==2.6.3
+# Cannot be removed as long as qrcode is included 
 Pillow>3.3.2
+qrcode>7.4
 pyrad==2.1
 sphinx==5.3.0
 sphinxcontrib-programoutput==0.17

tests/unittests/web/generate_qr_code_test.py

@@ -0,0 +1,6 @@
+from nav.web.seeddb.utils.generate_qr_code import generate_qr_code
+
+
+def test_generate_qr_code_returns_string():
+    qr_code = generate_qr_code(url="www.example.com", name="buick.lab.uninett.no")
+    assert isinstance(qr_code, str)