Today I had some issues on creating a table which used rowspan. The result in the calibre previewer did not show some borders, nor when viewing the epub with calibre. Only after a long time of trying and trying, it turned out that the resulting epub page was showing correct on my e-reader itself, but just not on the calibre (pre)viewer.
To test I used the following (test) html page:
Spoiler:
<?xml version='1.0' encoding='utf-8'?>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<style>
table {
border: solid thin;
border-collapse: collapse;
}
caption {
padding-bottom: 0.5em;
}
th, td {
border: solid thin;
padding: 0.5em 2em;
}
td {
white-space: nowrap;
}
th {
font-weight: normal;
}
td {
border-style: none solid;
vertical-align: top;
}
th {
padding: 0.2em;
vertical-align: middle;
text-align: center;
}
body {
padding: 1em;
}
</style>
</head>
<body>
<h1>TEST</h1>
<table id="table-example-1"><caption>Specification values: <b>Steel</b>, <b>Castings</b>,
Ann. A.S.T.M. A27-16, Class B;* P max. 0.06; S max. 0.05.</caption>
<thead><tr><th rowspan="2">Grade.</th>
<th rowspan="2">Yield Point.</th>
<th colspan="2">Ultimate tensile strength</th>
<th rowspan="2">Per cent elong. 50.8*mm or*2*in.</th>
<th rowspan="2">Per cent reduct. area.</th>
</tr><tr><th>kg/mm<sup>2</sup></th>
<th>lb/in<sup>2</sup></th>
</tr></thead><tbody><tr><td>Hard</td>
<td>0.45 ultimate</td>
<td>56.2</td>
<td>80,000</td>
<td>15</td>
<td>20</td>
</tr><tr><td>Medium</td>
<td>0.45 ultimate</td>
<td>49.2</td>
<td>70,000</td>
<td>18</td>
<td>25</td>
</tr><tr><td>Soft</td>
<td>0.45 ultimate</td>
<td>42.2</td>
<td>60,000</td>
<td>22</td>
<td>30</td>
</tr></tbody></table>
</body>
</html>
The code above produced the following result in the calibre previewer (picture1), in which borders where missing (indicated by red in picture2). These missing borders are showing on my e-readers.
Is this a known anomaly of the calibre (pre)viewer?