Selecting all rows under a particular column header (variable column headers) - xpath

Question

I have a table like this:
<table>
<tr class="header">
<td>
Col1
</td>
<td>
Col2
</td>
<td>
Col3
</td>
<td>
Col4
</td>
</tr>
<tr class="rowOdd">
<td>
Value1
</td>
<td>
Value2
</td>
<td>
Value3
</td>
<td>
Value4
</td>
</tr>
<tr class="rowEven">
<td>
Value1
</td>
<td>
Value2
</td>
<td>
Value3
</td>
<td>
Value4
</td>
</tr>
</table>
Essentially, what I want to do is to select all the rows under the designated column headers using Xpath. The column headers are actually shirt sizes from "5XS" to "6XL". The trick is that the number of columns varies per table. Some have 10 columns, others have 5 or less (i.e., less available shirt sizes). But the header names are fixed names: item_name, 5xs, 4xs, and so on. It's just that not all the sizes are always present in every table. So I have to write an xpath such that it searches for a particular header name (or shirt size) and get all the rows under that particular header name. I have tried this code and it seems to work:
*[count(../../tr/td[#class='header'][.='5xs']/preceding-sibling::*)+1]
However, my problem is if the header '5xs' is not present in the table I am currently processing, I get defaulted to the values of column1 (item_name). Is there a way for me to get blanks or not select rows at all if the particular header name I'm looking for is not present in the current table I'm looking at?
Thank you!

Answer 1

You can use xpath function contains. If you have different class names and markup structure like this i.e. you have different class names:
<table>
<tr class="header_Name1">
<td>
Col1
</td>
</tr>
<tr>
<td>
Value1
</td>
</tr>
<tr class="header_Name2">
<td>
Col2
</td>
</tr>
<tr>
<td>
Value1
</td>
</tr>
</table>
The following:
//tr[contains(#class,'header_Name')]
Should return:
["\nCol1\n\n", "\nCol2\n\n"]