如何使用HTML中的XPath为具有相同类的父母匹配不同数量的子元素？

Question

I have a webpage with the following structure, and I'm extracting data from it via XPath Helper Google Chrome extenson

<div class="example">
   <span class="name">John Doe</span>
   <span class="foo">1</div>
</div>
<div class="example">
   <span class="name">Jane Doe</span>   
</div>
<div class="example">
   <span class="name">Richard Roe</span>
</div>
<div class="example">
   <span class="name">Jane Roe</span>
   <span class="foo">2</div>
</div>

I want to use XPath to select name and foo of each example variable. If the variable doesn't have a foo value, it should display me 0 , blank or NULL so I can match each name with each foo

This query //div[@class="example"]/span[@class="name"] can return all the names

John Doe
Jane Doe
Richard Roe
Jane Roe

However with this query //div[@class="example"]/span[@class="foo"] I only get a result when foo exists

1
2

With the combination of those two queries alone I can't track which foo belongs to each name under the example div.

I ideally need a query which returns

John Doe, 1
Jane Doe, 0
Richard Roe, 0
Jane Roe, 2

However if I can get a query with only the second part

1
0
0
2

It'd work as well because I could match the results with the respective names.

How do I build a query to do this job with XPath 1.0?

Answer 1

With XPath 2.0 you could use a for loop as :

for $ex in //div[@class='example']
 return concat( $ex/span[@class='name'], ',', sum($ex/span[@class='foo'], '0'))

It returns :

John Doe,1
Jane Doe,0
Richard Roe,0
Jane Roe,2