write_html: fit a table wider than the page to the page width, and ignore a negative width (#2017)

Author: RavSinghChandan

CHANGELOG.md

@@ -41,6 +41,7 @@ This can also be enabled programmatically with `warnings.simplefilter('default',
 * `FPDF.write_html()` numbers an `<ol>` with an unknown `type`, such as `type="disc"`, as 1, 2, 3, like browsers, instead of raising `NotImplementedError` - thanks to @RavSinghChandan
 * `FPDF.write_html()` no longer raises `KeyError: 'href'` on an `<a>` element without an `href` attribute, such as a named anchor (`<a name="intro">`); its text is rendered as plain text - thanks to @RavSinghChandan
 * `FPDF.write_html()` treats an invalid `colspan` or `rowspan` on `<td>` / `<th>`, or one below 1, as 1 like browsers do, instead of raising `ValueError` or `ZeroDivisionError` - thanks to @RavSinghChandan
+* `FPDF.write_html()` renders a `<table>` whose `width` is wider than the page, such as `width="150%"`, at the page width with a warning, and ignores a negative `width` like browsers, instead of raising `ValueError` - thanks to @RavSinghChandan
 * warning detection during `FPDFRecorder.replay()` now correctly identifies context managers (`contextlib.AbstractContextManager`, `@contextmanager`, custom context managers) within `unbreakable()` sections
 * SVG import: `opacity`, `fill-opacity` and `stroke-opacity` accept percentages (`50%`), and an out-of-range `opacity` is clamped to 0-1 like the other two instead of raising `ValueError` - thanks to @RavSinghChandan
 * css `rgb()` colors accept percentages, as in `rgb(100%, 0%, 50%)` (clamped to 0%-100%), in SVG import and `FPDF.write_html()` instead of raising `ValueError` - thanks to @RavSinghChandan

fpdf/html.py

@@ -1159,6 +1159,14 @@ def handle_starttag(self, tag: str, attrs: list[tuple[str, str | None]]) -> None
                     width = self.pdf.epw * float(width_str[:-1]) / 100
                 else:
                     width = _parse_html_dimension(width_str) / self.pdf.k
+                if width <= 0:  # like browsers, an invalid width is ignored
+                    width = None
+                elif width > self.pdf.epw:
+                    LOGGER.warning(
+                        'Table width="%s" is wider than the page: using the page width',
+                        width_str,
+                    )
+                    width = self.pdf.epw
             if "border" not in attrs_dict:  # default borders
                 borders_layout = (
                     "HORIZONTAL_LINES"

test/html/test_html_table.py

@@ -554,3 +554,27 @@ def test_html_table_invalid_span_counts_as_one(tmp_path, span, value, text):
         render_span_table(span, f' {span}="1"', text),
         tmp_path,
     )
+
+
+@pytest.mark.parametrize("width", ["150%", "1000px", ' style="width: 120%"'])
+def test_html_table_wider_than_the_page_uses_the_page_width(tmp_path, caplog, width):
+    attribute = width if width.startswith(" ") else f' width="{width}"'
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.write_html(f"<table{attribute}><tr><td>a</td><td>b</td></tr></table>")
+    assert "wider than the page" in caplog.text
+    expected = FPDF()
+    expected.add_page()
+    expected.write_html('<table width="100%"><tr><td>a</td><td>b</td></tr></table>')
+    assert_pdf_equal(pdf, expected, tmp_path)
+
+
+@pytest.mark.parametrize("width", ["-50%", "-10"])
+def test_html_table_with_a_negative_width_ignores_it(tmp_path, width):
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.write_html(f'<table width="{width}"><tr><td>a</td><td>b</td></tr></table>')
+    expected = FPDF()
+    expected.add_page()
+    expected.write_html("<table><tr><td>a</td><td>b</td></tr></table>")
+    assert_pdf_equal(pdf, expected, tmp_path)