diff --git a/nbconvert/exporters/html.py b/nbconvert/exporters/html.py
index 055e69915..367039d7a 100644
--- a/nbconvert/exporters/html.py
+++ b/nbconvert/exporters/html.py
@@ -211,7 +211,7 @@ def default_config(self):
@validate("language_code")
def _valid_language_code(self, proposal):
if self.language_code not in iso639_1:
- self.log.warn(
+ self.log.warning(
f'"{self.language_code}" is not an ISO 639-1 language code. '
'It has been replaced by the default value "en".'
)
@@ -259,8 +259,12 @@ def from_notebook_node( # type:ignore
html, resources = super().from_notebook_node(nb, resources, **kw)
soup = BeautifulSoup(html, features="html.parser")
# Add image's alternative text
+ missing_alt = 0
for elem in soup.select("img:not([alt])"):
- elem.attrs["alt"] = "Image"
+ elem.attrs["alt"] = "No description has been provided for this image"
+ missing_alt += 1
+ if missing_alt:
+ self.log.warning(f"Alternative text is missing on {missing_alt} image(s).")
# Set input and output focusable
for elem in soup.select(".jp-Notebook div.jp-Cell-inputWrapper"):
elem.attrs["tabindex"] = "0"
diff --git a/nbconvert/exporters/tests/test_html.py b/nbconvert/exporters/tests/test_html.py
index 04c2a74f8..3b8be156d 100644
--- a/nbconvert/exporters/tests/test_html.py
+++ b/nbconvert/exporters/tests/test_html.py
@@ -73,10 +73,17 @@ def test_png_metadata(self):
"""
Does HTMLExporter with the 'classic' template treat pngs with width/height metadata correctly?
"""
- (output, resources) = HTMLExporter(template_name="classic").from_filename(
- self._get_notebook(nb_name="pngmetadata.ipynb")
+ exporter = HTMLExporter(template_name="classic")
+ with self.assertLogs(exporter.log, level="WARN") as log:
+ (output, resources) = exporter.from_filename(
+ self._get_notebook(nb_name="pngmetadata.ipynb")
+ )
+ assert len(log.output) == 1
+ assert "Alternative text is missing on 1 image(s)." in log.output[0]
+
+ check_for_png = re.compile(
+ r'![No description has been provided for this image]()
]*?)>'
)
- check_for_png = re.compile(r'![Image]()
]*?)>')
result = check_for_png.search(output)
assert result
attr_string = result.group(1)
@@ -198,3 +205,23 @@ def test_javascript_injection(self):
assert "" not in output
assert "" not in output
assert "alert('application/javascript output')" not in output
+
+ def test_language_code_not_set(self):
+ (output, resources) = HTMLExporter(template_name="classic").from_filename(
+ self._get_notebook()
+ )
+ assert '' in output
+
+ def test_set_language_code(self):
+ exporter = HTMLExporter(template_name="classic", language_code="fr")
+ (output, resources) = exporter.from_filename(self._get_notebook())
+ assert '' in output
+
+ def test_language_code_error(self):
+ with self.assertLogs(level="WARN") as log:
+ exporter = HTMLExporter(template_name="classic", language_code="zz")
+ assert len(log.output) == 1
+ assert '"zz" is not an ISO 639-1 language code.' in log.output[0]
+ (output, resources) = exporter.from_filename(self._get_notebook())
+
+ assert '' in output