misc: add |convert_image_format filter tag (#86003)

debian/control

@@ -43,7 +43,8 @@ Depends: graphviz,
          uwsgi-plugin-python3,
          ${misc:Depends},
          ${python3:Depends},
-Recommends: libreoffice-writer-nogui | libreoffice-writer,
+Recommends: graphicsmagick,
+            libreoffice-writer-nogui | libreoffice-writer,
             poppler-utils,
             python3-docutils,
             python3-langdetect,

tests/test_templates.py

@@ -2,6 +2,8 @@ import datetime
 import html
 import os
 import string
+import subprocess
+from unittest import mock
 
 import pytest
 from django.test import override_settings
@@ -1696,3 +1698,83 @@ def test_details_format(pub):
     pub.loggederror_class.wipe()
     assert tmpl.render(context) == 'String:\n  foo'
     assert pub.loggederror_class.count() == 0
+
+
+@pytest.mark.parametrize('image_format', ['jpeg', 'png', 'pdf'])
+def test_convert_image_format(pub, image_format):
+    with pub.complex_data():
+        img = Template('{{ url|qrcode|convert_image_format:"%s" }}' % image_format).render(
+            {'url': 'http://example.com/', 'allow_complex': True}
+        )
+        assert pub.has_cached_complex_data(img)
+        value = pub.get_cached_complex_data(img)
+        assert value.orig_filename == 'qrcode.%s' % image_format
+        assert value.content_type == {'jpeg': 'image/jpeg', 'png': 'image/png', 'pdf': 'application/pdf'}.get(
+            image_format
+        )
+        with value.get_file_pointer() as fp:
+            if image_format in ('jpeg', 'png'):
+                img = PIL.Image.open(fp)
+                assert img.format == image_format.upper()
+                assert img.size == (330, 330)
+                assert (
+                    zbar_decode_qrcode(img, symbols=[ZBarSymbol.QRCODE])[0].data.decode()
+                    == 'http://example.com/'
+                )
+            else:
+                assert b'%PDF-' in fp.read()[:200]
+
+
+def test_convert_image_format_no_name(pub):
+    with pub.complex_data():
+        img = Template('{{ url|qrcode|rename_file:""|convert_image_format:"jpeg" }}').render(
+            {'url': 'http://example.com/', 'allow_complex': True}
+        )
+        assert pub.has_cached_complex_data(img)
+        value = pub.get_cached_complex_data(img)
+        assert value.orig_filename == 'file.jpeg'
+
+
+def test_convert_image_format_errors(pub):
+    pub.loggederror_class.wipe()
+    with pub.complex_data():
+        img = Template('{{ "xxx"|convert_image_format:"gif" }}').render({'allow_complex': True})
+        assert pub.has_cached_complex_data(img)
+        assert pub.get_cached_complex_data(img) is None
+    assert pub.loggederror_class.count() == 1
+    assert (
+        pub.loggederror_class.select()[0].summary
+        == '|convert_image_format: unknown format (must be one of jpeg, pdf, png)'
+    )
+
+    pub.loggederror_class.wipe()
+    with pub.complex_data():
+        img = Template('{{ "xxx"|convert_image_format:"jpeg" }}').render({'allow_complex': True})
+        assert pub.has_cached_complex_data(img)
+        assert pub.get_cached_complex_data(img) is None
+    assert pub.loggederror_class.count() == 1
+    assert pub.loggederror_class.select()[0].summary == '|convert_image_format: missing input'
+
+    pub.loggederror_class.wipe()
+    with mock.patch('subprocess.run', side_effect=FileNotFoundError()):
+        with pub.complex_data():
+            img = Template('{{ url|qrcode|convert_image_format:"jpeg" }}').render(
+                {'url': 'http://example.com/', 'allow_complex': True}
+            )
+            assert pub.has_cached_complex_data(img)
+            assert pub.get_cached_complex_data(img) is None
+    assert pub.loggederror_class.count() == 1
+    assert pub.loggederror_class.select()[0].summary == '|convert_image_format: not supported'
+
+    pub.loggederror_class.wipe()
+    with mock.patch(
+        'subprocess.run', side_effect=subprocess.CalledProcessError(returncode=-1, cmd='xx', stderr=b'xxx')
+    ):
+        with pub.complex_data():
+            img = Template('{{ url|qrcode|convert_image_format:"jpeg" }}').render(
+                {'url': 'http://example.com/', 'allow_complex': True}
+            )
+            assert pub.has_cached_complex_data(img)
+            assert pub.get_cached_complex_data(img) is None
+    assert pub.loggederror_class.count() == 1
+    assert pub.loggederror_class.select()[0].summary == '|convert_image_format: conversion error (xxx)'

wcs/qommon/templatetags/qommon.py

@@ -24,6 +24,7 @@ import math
 import os
 import random
 import string
+import subprocess
 import urllib.parse
 from decimal import Decimal
 from decimal import DivisionByZero as DecimalDivisionByZero
@@ -1086,6 +1087,58 @@ def rename_file(value, new_name):
     return file_object
 
 
+@register.filter
+def convert_image_format(value, new_format):
+    from wcs.fields import FileField
+
+    formats = {
+        'jpeg': 'image/jpeg',
+        'pdf': 'application/pdf',
+        'png': 'image/png',
+    }
+    if new_format not in formats:
+        get_publisher().record_error(
+            _('|convert_image_format: unknown format (must be one of %s)') % ', '.join(formats.keys())
+        )
+        return None
+
+    try:
+        file_object = FileField.convert_value_from_anything(value)
+    except ValueError:
+        file_object = None
+    if not file_object:
+        get_publisher().record_error(_('|convert_image_format: missing input'))
+        return None
+
+    if file_object.base_filename:
+        current_name, current_format = os.path.splitext(file_object.base_filename)
+        if current_format == f'.{new_format}':
+            return file_object
+        new_name = f'{current_name}.{new_format}'
+    else:
+        new_name = '%s.%s' % (_('file'), new_format)
+
+    try:
+        proc = subprocess.run(
+            ['gm', 'convert', '-', f'{new_format}:-'],
+            input=file_object.get_content(),
+            capture_output=True,
+            check=True,
+        )
+    except FileNotFoundError:
+        get_publisher().record_error(_('|convert_image_format: not supported'))
+        return None
+    except subprocess.CalledProcessError as e:
+        get_publisher().record_error(_('|convert_image_format: conversion error (%s)' % e.stderr.decode()))
+        return None
+
+    new_file_object = FileField.convert_value_from_anything(
+        {'content': proc.stdout, 'filename': new_name, 'content_type': formats[new_format]}
+    )
+
+    return new_file_object
+
+
 @register.filter
 def first(value):
     try: