write_html: do not style header row if no <th> is present - fix #740

CHANGELOG.md

@@ -17,9 +17,10 @@ in order to get warned about deprecated features used in your code.
 This can also be enabled programmatically with `warnings.simplefilter('default', DeprecationWarning)`.
 
 ## [2.7.4] - Not released yet
-
 ### Added
 - documentation on how to embed `graphs` and `charts` generated using `Pygal` lib: [documentation section](https://pyfpdf.github.io/fpdf2/Maths.html#using-pygal) - thanks to @ssavi-ict
+### Changed
+- [`FPDF.write_html()`](https://pyfpdf.github.io/fpdf2/fpdf/fpdf.html#fpdf.fpdf.FPDF.write_html) does not render the top row as a header, in bold with a line below, when no `<th>` are used, in order to be more backward-compatible with earlier versions of `fpdf2` - _cf._ [#740](https://github.com/PyFPDF/fpdf2/issues/740)
 
 ## [2.7.3] - 2023-04-03
 ### Fixed
@@ -29,7 +30,6 @@ This can also be enabled programmatically with `warnings.simplefilter('default',
 ### Fixed
 - custom fonts can be used with `FPDF.table()` without triggering a `TypeError: cannot pickle 'dict_keys' object` - thanks @aeris07 for the bug report
 - the SVG parser now accepts `<rect>` with `width` / `height` defined as percents
-
 ### Added
 - documentation on how to generate Code128 barcodes using the `python-barcode` lib: [documentation section](https://pyfpdf.github.io/fpdf2/Barcodes.html#Code128)
 

fpdf/html.py

@@ -10,8 +10,9 @@
 from html.parser import HTMLParser
 
 from .enums import TextEmphasis, XPos, YPos
+from .errors import FPDFException
 from .fonts import FontFace
-from .table import Table
+from .table import Table, TableBordersLayout
 
 import re
 
@@ -447,13 +448,23 @@ def handle_starttag(self, tag, attrs):
             )
             self.pdf.ln()
         if tag == "tr":
+            if not self.table:
+                raise FPDFException("Invalid HTML: <tr> used outside any <table>")
             self.tr = {k.lower(): v for k, v in attrs.items()}
             self.table_row = self.table.row()
         if tag in ("td", "th"):
+            if not self.table_row:
+                raise FPDFException(f"Invalid HTML: <{tag}> used outside any <tr>")
             self.td_th = {k.lower(): v for k, v in attrs.items()}
             if tag == "th":
                 self.td_th["align"] = "CENTER"
                 self.td_th["b"] = True
+            elif len(self.table.rows) == 1 and not self.table_row.cells:
+                # => we are in the 1st <tr>, and the 1st cell is a <td>
+                # => we do not treat the first row as a header
+                # pylint: disable=protected-access
+                self.table._borders_layout = TableBordersLayout.NONE
+                self.table._first_row_as_headings = False
             if "height" in attrs:
                 LOGGER.warning(
                     'Ignoring unsupported height="%s" specified on a <%s>',

fpdf/table.py

@@ -186,7 +186,11 @@ def get_cell_border(self, i, j):
     def _render_table_row(self, i, fill=False, **kwargs):
         row = self.rows[i]
         lines_heights_per_cell = self._get_lines_heights_per_cell(i)
-        row_height = max(sum(lines_heights) for lines_heights in lines_heights_per_cell)
+        row_height = (
+            max(sum(lines_heights) for lines_heights in lines_heights_per_cell)
+            if lines_heights_per_cell
+            else 0
+        )
         j = 0
         while j < len(row.cells):
             cell_line_height = row_height / len(lines_heights_per_cell[j])

test/html/test_html_table.py

@@ -0,0 +1,228 @@
+from pathlib import Path
+
+import pytest
+
+from fpdf import FPDF, FPDFException
+from test.conftest import assert_pdf_equal
+
+
+HERE = Path(__file__).resolve().parent
+
+
+def test_html_table_simple(tmp_path):
+    pdf = FPDF()
+    pdf.set_font_size(30)
+    pdf.add_page()
+    pdf.write_html(
+        """<table><thead><tr>
+        <th width="25%">left</th><th width="50%">center</th><th width="25%">right</th>
+    </tr></thead><tbody><tr>
+        <td>1</td><td>2</td><td>3</td>
+    </tr><tr>
+        <td>4</td><td>5</td><td>6</td>
+    </tr></tbody></table>"""
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_simple.pdf", tmp_path)
+
+
+def test_html_table_line_separators(tmp_path):
+    pdf = FPDF()
+    pdf.set_font_size(30)
+    pdf.add_page()
+    pdf.write_html(
+        """<table><thead><tr>
+        <th width="25%">left</th><th width="50%">center</th><th width="25%">right</th>
+    </tr></thead><tbody><tr>
+        <td>1</td><td>2</td><td>3</td>
+    </tr><tr>
+        <td>4</td><td>5</td><td>6</td>
+    </tr></tbody></table>""",
+        table_line_separators=True,
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_line_separators.pdf", tmp_path)
+
+
+def test_html_table_th_inside_tr_issue_137(tmp_path):
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.write_html(
+        """<table border="1">
+    <tr>
+        <th width="40%">header1</th>
+        <th width="60%">header2</th>
+    </tr>
+    <tr>
+        <th>value1</th>
+        <td>value2</td>
+    </tr>
+</table>"""
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_line_separators_issue_137.pdf", tmp_path)
+
+
+def test_html_table_with_border(tmp_path):
+    pdf = FPDF()
+    pdf.set_font_size(30)
+    pdf.add_page()
+    pdf.write_html(
+        """<table border="1"><thead><tr>
+        <th width="25%">left</th><th width="50%">center</th><th width="25%">right</th>
+    </tr></thead><tbody><tr>
+        <td>1</td><td>2</td><td>3</td>
+    </tr><tr>
+        <td>4</td><td>5</td><td>6</td>
+    </tr></tbody></table>"""
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_with_border.pdf", tmp_path)
+
+
+def test_html_table_with_img(caplog, tmp_path):
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.write_html(
+        """<table>
+        <tr>
+            <td width="50%">
+                <img src="test/image/png_images/affc57dfffa5ec448a0795738d456018.png" height="235" width="435"/>
+            </td>
+            <td width="50%">
+                <img src="test/image/image_types/insert_images_insert_png.png" height="162" width="154"/>
+            </td>
+        </tr>
+    </table>"""
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_with_img.pdf", tmp_path)
+    assert 'Ignoring unsupported "width" / "height" set on <img> element' in caplog.text
+
+
+def test_html_table_with_img_without_explicit_dimensions(tmp_path):
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.write_html(
+        """<table>
+        <tr>
+            <td width="50%">
+                <img src="test/image/png_images/affc57dfffa5ec448a0795738d456018.png"/>
+            </td>
+            <td width="50%">
+                <img src="test/image/image_types/insert_images_insert_png.png"/>
+            </td>
+        </tr>
+    </table>"""
+    )
+    assert_pdf_equal(
+        pdf, HERE / "html_table_with_img_without_explicit_dimensions.pdf", tmp_path
+    )
+
+
+def test_html_table_with_imgs_captions_and_colspan(caplog, tmp_path):
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.write_html(
+        """<table border="1">
+        <tr>
+            <td colspan="2" align="center"><b>Side by side centered pictures and captions</b></td>
+        </tr>
+        <tr>
+            <td width="50%" align="center"><img src="docs/fpdf2-logo.png"/></td>
+            <td width="50%" align="center"><img src="docs/fpdf2-logo.png"/></td>
+        </tr>
+        <tr>
+            <td width="50%" align="center">left caption</td>
+            <td width="50%" align="center">right caption</td>
+        </tr>
+    </table>"""
+    )
+    assert_pdf_equal(
+        pdf, HERE / "html_table_with_imgs_captions_and_colspan.pdf", tmp_path
+    )
+    assert (
+        'Ignoring width="50%" specified on a <td> that is not in the first <tr>'
+        in caplog.text
+    )
+
+
+def test_html_table_with_empty_cell_contents(tmp_path):  # issue 349
+    pdf = FPDF()
+    pdf.set_font_size(30)
+    pdf.add_page()
+    # Reference table cells positions:
+    pdf.write_html(
+        """<table><thead><tr>
+        <th width="25%">left</th><th width="50%">center</th><th width="25%">right</th>
+    </tr></thead><tbody><tr>
+        <td>1</td><td>2</td><td>3</td>
+    </tr><tr>
+        <td>4</td><td>5</td><td>6</td>
+    </tr></tbody></table>"""
+    )
+    # Table with empty cells:
+    pdf.write_html(
+        """<table><thead><tr>
+        <th width="25%">left</th><th width="50%">center</th><th width="25%">right</th>
+    </tr></thead><tbody><tr>
+        <td>1</td><td></td><td>3</td>
+    </tr><tr>
+        <td></td><td>5</td><td></td>
+    </tr></tbody></table>"""
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_with_empty_cell_contents.pdf", tmp_path)
+
+
+def test_html_table_with_bgcolor(tmp_path):  # issue-512
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.write_html(
+        """<table>
+    <thead>
+        <tr>
+            <th width="25%">Career</th>
+            <th width="75%">Quote</th>
+        </tr>
+    </thead>
+    <tbody>
+        <tr bgcolor="grey"><td>Engineer</td><td>The engineer has been, and is, a maker of history.</td></tr>
+        <tr bgcolor="white"><td>Developer</td><td>Logical thinking, passion and perseverance is the paint on your palette.</td></tr>
+        <tr bgcolor="grey"><td>Analyst</td><td>Seeing what other people can't see gives you great vision.</td></tr>
+        <tr bgcolor="white"><td><i>None of the above</i></td><td>I'm sorry. We could not find a quote for your job.</td></tr>
+    </tbody>
+</table>"""
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_with_bgcolor.pdf", tmp_path)
+
+
+def test_html_table_with_only_tds(tmp_path):  # issue-740
+    pdf = FPDF()
+    pdf.set_font_size(30)
+    pdf.add_page()
+    pdf.write_html(
+        """<table><tr>
+        <td>left</td><td>center</td><td>right</td>
+    </tr><tr>
+        <td>1</td><td>2</td><td>3</td>
+    </tr><tr>
+        <td>4</td><td>5</td><td>6</td>
+    </tr></table>"""
+    )
+    assert_pdf_equal(pdf, HERE / "html_table_with_only_tds.pdf", tmp_path)
+
+
+def test_html_table_invalid(caplog):
+    pdf = FPDF()
+    pdf.set_font_size(30)
+    pdf.add_page()
+    # OK with empty tables:
+    pdf.write_html("<table></table>")
+    pdf.write_html("<table><tr></tr></table>")
+    pdf.write_html("<table><tr><td></td></tr></table>")
+    # KO if some elements are missing:
+    with pytest.raises(FPDFException) as error:
+        pdf.write_html("<table><td></td></table>")
+    assert str(error.value) == "Invalid HTML: <td> used outside any <tr>"
+    with pytest.raises(FPDFException) as error:
+        pdf.write_html("<table><th></th></table>")
+    assert str(error.value) == "Invalid HTML: <th> used outside any <tr>"
+    with pytest.raises(FPDFException) as error:
+        pdf.write_html("<tr></tr>")
+    assert str(error.value) == "Invalid HTML: <tr> used outside any <table>"
+    assert caplog.text == ""