Xpath - how to differentiate nodes without attributes? - xpath

Question

I want to extract a value from xml via xpath and I'm struggling a bit. This is the example of xml I have to work with
<data>
<menu>
<date>2017-10-30</date>
<type>S</type>
<name>onion soup</name>
</menu>
<menu>
<date>2017-10-30</date>
<type>L</type>
<name>ham sandwich</name>
</menu>
<menu>
<date>2017-10-31</date>
<type>S</type>
<name>pumpkin soup</name>
</menu>
<menu>
<date>2017-10-31</date>
<type>L</type>
<name>cheese sandwich</name>
</menu>
<menu>
<date>2017-11-1</date>
<type>S</type>
<name>sweet potato soup</name>
</menu>
<menu>
<date>2017-11-1</date>
<type>L</type>
<name>chicken sandwich</name>
</menu>
</data>
The dates and meal names are dynamically changing.
Now I have 2 columns, for Today's soup and Tomorrow's. I know how to link to xml via xpath for today's soup:
/data/menu/name[../type/text() = "S"] or /data/menu[type[text()='S']]/name
But I struggle with tomorrow's as my xml feed doesn't have any attributes to differentiate, types are the same for both dates and date is constantly changing.
Thanks for any help.
Edit:
Thank you for anwering.
I think I described my problem wrong.
I should probably point out that I'm using Xpath build-in feature in one of the local software.
You're right, these lines
/data/menu[type='S' and date='2017-10-31']]/name
are for all the soups, I just wrongly described it by how it behaves on my end, where it gives me just the value of the first one.
/data/menu[type='S' and date='2017-11-01']]/name
will give me Tommorow's soup, but if I want to use output for this value in static column "Tommorow's soup" next to which I want my xpath output it will only be true for one day. What I need is for it to be true also for next days.
I need a line that will give me "tommorow's soup" which is suppose to be Pumpkin soup today, tommorow when the xml updates it would be Sweet Potato soup and day after that it will be some new soup which is going to be updated later with the whole xml.
If I use
/data/menu[type='S' and date='2017-10-30']]/name
it will not show anything tommorow since there won't be a 2017-10-30 because the xml will update and will start with 2017-10-31.
I hope it's clearer now what I'm asking. I know it's still confusing it's kinda hard for me to describe it in English especially since I'm beginner when it comes to Xpath.

Answer 1

How to differentiate elements without attributes? Use other elements...
But first to clear up a wrong assumption:
Now I have 2 columns, for Today's soup and Tomorrow's. I know how to
link to xml via xpath for today's soup:
/data/menu/name[../type/text() = "S"] or
/data/menu[type[text()='S']]/name
Actually, the XPaths that you say will give you today's soups will actually give you all soups regardless of date.
XPath 1.0
XPath 1.0 has no date functions1, so you'll have to pass the current date and tomorrow's date into your XPAth, and you're on your own to test the date element's value as a string:
If today is 2017-10-31, then this XPath will give you the names of today's soups,
/data/menu[type='S' and date='2017-10-31']]/name
and this XPath will give you the names of tomorrow's soups:
/data/menu[type='S' and date='2017-11-1']]/name
1
XPath 2.0 and 3.0's dynamic context includes a current-dateTime() function, but its format is implementation-dependent, which limits its usefulness. You might be able to use date calculations to determine tomorrow's date, but unless you want to be dependent upon an implementation-defined format for current-dateTime(), you'll have to pass today into your XPath at least.