xpath: How to select only nearby parent siblings of current child node? - xpath

Question

Im using xpath 1.0 and i want to select a siblings of a parent of a current child node.
The current node that im in is <w:instrText> and how can i get the parent sibling nodes <w:r> that only in range of <!-- SELECT FROM HERE --> and <!-- SELECT TILL HERE -->?
<w:p>
<w:pPr>
<w:rPr>
<w:lang w:val='en-US'/>
</w:rPr>
</w:pPr>
<w:r>
<w:t>TEXT 1</w:t>
</w:r>
<w:r w:rsidR='002D5530'>
<w:t xml:space='preserve'> </w:t>
</w:r>
<!-- SELECT FROM HERE -->
<w:r w:rsidR='002D5530'>
<w:fldChar w:fldCharType='begin'/>
</w:r>
<w:r w:rsidR='002D5530'>
<w:instrText xml:space='preserve'> SOME DYNAMIC TEXT THAT CAN CHANGE </w:instrText> <!-- My cursor is here! -->
</w:r>
<w:r w:rsidR='002D5530'>
<w:fldChar w:fldCharType='separate'/>
</w:r>
<w:r w:rsidR='00E5783C'>
<w:t>SOME DYNAMIC TEXT</w:t>
</w:r>
<w:r w:rsidR='002D5530'>
<w:fldChar w:fldCharType='end'/>
</w:r>
<!-- SELECT TILL HERE -->
<w:r w:rsidR='002D5530'>
<w:fldChar w:fldCharType='begin'/>
</w:r>
<w:r w:rsidR='002D5530'>
<w:instrText xml:space='preserve'> SOME DYNAMIC TEXT THAT CAN CHANGE </w:instrText>
</w:r>
<w:r w:rsidR='002D5530'>
<w:fldChar w:fldCharType='separate'/>
</w:r>
<w:r w:rsidR='00E5783C'>
<w:t>SOME DYNAMIC TEXT</w:t>
</w:r>
<w:r w:rsidR='002D5530'>
<w:fldChar w:fldCharType='end'/>
</w:r>
</w:p>
This is what i tried but got only 3 nodes...
../preceding-sibling::w:r[w:fldChar/#w:fldCharType='begin'] | ../following-sibling::w:r[w:fldChar/#w:fldCharType='end']

Answer 1

Given the limitations of XPath 1.0 and the assumption that the order of the sets of five w:r elements is consistent you could use a somewhat brute-force approach like:
(
(../preceding-sibling::w:r[w:fldChar/#w:fldCharType='begin'])[last()],
(../following-sibling::w:r[w:fldChar/#w:fldCharType='separate'])[position() = 1],
(../following-sibling::w:r[w:t])[position() = 1],
(../following-sibling::w:r[w:fldChar/#w:fldCharType='end'])[position() = 1]
)
Which is forming a sequence of four elements:
the last of the preceding "begin" elements
the first of the following "separate" elements
the first of the following "t" elements (w:r containing a w:t)
the first of the following "end" elements
If you also need to include the immediate parent of your context, then just add .. or parent::* or parent::w:r to the sequence:
(
(../preceding-sibling::w:r[w:fldChar/#w:fldCharType='begin'])[last()],
..,
(../following-sibling::w:r[w:fldChar/#w:fldCharType='separate'])[position() = 1],
(../following-sibling::w:r[w:t])[position() = 1],
(../following-sibling::w:r[w:fldChar/#w:fldCharType='end'])[position() = 1]
)
However, this may not be efficient if your input document is huge or performance is a significant factor.
If you are curious why your attempt returned three elements instead of two it is probably because you selected both "end" elements that were beyond the position of your context. The answer here may not be precisely what you need, but I suspect the last()/position() predicate examples will set you in the right direction.
BTW, if you ever have the opportunity to use XQuery for something like this, it is a perfect use case for the XQuery 3 "tumbling window" syntax which makes it very easy to identify the boundaries of sibling groups and iterate over the groups.