Nokogiri move node to parent's sibling - ruby-on-rails

Question

My task is to translate an XML table to an HTML table. The problem is that the XML does not follow HTML convention, I am going to have to move nodes to the right place. The headers are pre-ordered instead of level-ordered, and there are table notes between the last table row and the closing table tag.
I solved the pre-order to level-order conversion issue by computing and creating the HTML using a builder and then replacing the XML table header with the HTML that I generated. But the last issue, which should be simple, has given me a mental blowout. I need to move the <TNOTE> out of the <GPOTABLE> and put it in a <div> immediately after </GPOTABLE>.
The XML data snippet is:
<P>(vi) Grinding wheels or discs for vertical single-spindle disc grinders shall be encircled with hoods to remove the dust generated in the operation. The hoods shall be connected to one or more branch pipes having exhaust volumes as shown in Table D-57.5.</P>
<GPOTABLE CDEF="s15,6,6,6,6" COLS="5" OPTS="L2">
<TTITLE>Table D-57.5—Vertical Spindle Disc Grinder</TTITLE>
<BOXHD>
<CHED H="1">Disc diameter, inches (cm)</CHED>
<CHED H="1">One-half or more of disc covered</CHED>
<CHED H="2">Number <SU>1</SU>
</CHED>
<CHED H="2">Exhaust foot <SU>3</SU>/min.</CHED>
<CHED H="1">Disc not covered</CHED>
<CHED H="2">Number <SU>1</SU>
</CHED>
<CHED H="2">Exhaust foot<SU>3</SU>/min.</CHED>
</BOXHD>
<ROW>
<ENT I="01">Up to 20 (50.8)</ENT>
<ENT>1</ENT>
<ENT>500</ENT>
<ENT>2</ENT>
<ENT>780</ENT>
</ROW>
<!-- ....snip .... -->
<ROW>
<ENT I="01">Over 53 to 72 (134.62 to 182.88)</ENT>
<ENT>2</ENT>
<ENT>3,140</ENT>
<ENT>5</ENT>
<ENT>6,010</ENT>
</ROW>
<TNOTE>
<SU>1</SU> Number of exhaust outlets around periphery of hood, or equal distribution provided by other means.</TNOTE>
</GPOTABLE>
<P>(vii) Grinding and polishing belts shall be provided with hoods to remove dust and dirt generated in the operations and the hoods shall be connected to branch pipes having exhaust volumes as shown in Table D-57.6.</P>
After conversion to HTML, it should look something like this:
<table cdef="s15,6,6,6,6" cols="5" opts="L2">
<caption>Table D-57.5—Vertical Spindle Disc Grinder</caption>
<tr>
<th rowspan="2" colspan="1" class="table_header">Disc diameter, inches (cm)</th>
<th rowspan="1" colspan="2" class="table_header">One-half or more of disc covered</th>
<th rowspan="1" colspan="2" class="table_header">Disc not covered</th>
</tr>
<tr>
<th rowspan="1" colspan="1" class="table_header">Number <su>1</su></th>
<th rowspan="1" colspan="1" class="table_header">Exhaust foot <su>3</su>/min.</th>
<th rowspan="1" colspan="1" class="table_header">Number <su>1</su> </th>
<th rowspan="1" colspan="1" class="table_header">Exhaust foot<su>3</su>/min.</th>
</tr>
<tr>
<td i="01">Up to 20 (50.8)</td>
<td>1</td>
<td>500</td>
<td>2</td>
<td>780</td>
</tr>
<!-- .... snip .... -->
<tr>
<td i="01">Over 53 to 72 (134.62 to 182.88)</td>
<td>2</td>
<td>3,140</td>
<td>5</td>
<td>6,010</td>
</tr>
</table>
<div class='tnote'><su>1</su> Number of exhaust outlets around periphery of hood, or equal distribution provided by other means</div>
Here's what I've got so far:
def xslt_tables(xml_text)
frag = Nokogiri::HTML(xml_text)
frag.xpath("//gpotable").each do |table|
TableConverter.new(table)
table.name = 'table'
end
frag.inner_html
end
class TableConverter
attr_accessor :data, :rows, :columns, :frag
# Expects a nokogiri object (a single <gpotable> node), not merely an html fragment
def initialize(nokogiri_fragment)
#column_index = 0
#frag = nokogiri_fragment
puts "find table size..."
find_table_size()
puts "populating the grid..."
populate_grid()
puts "computing rowspans and colspans, save in #data..."
compute_rowspans_and_colspans()
puts "assemble headers from #data"
nokogiri_headers = html_headers()
puts "replace the boxhd with nokogiri_headers, translate remaining table entities"
replace_nodes(nokogiri_headers)
end
# .... snip ....
def replace_nodes(headers)
# note: this actually changes values in the original nokogiri object!
# I'll leave it to the calling script to change the name to <table>
# #frag.xpath("//gpotable").each do |table|
# puts "renaming //gpotable"
# table.name = 'table'
# end
#frag.xpath("ttitle").each do |cap|
puts "replacing ttitle with caption"
cap.name = 'caption'
end
#frag.xpath("boxhd").each do |old|
puts "replacing boxhd with generated th with computed rowspan and colspan"
old.replace headers
end
#frag.xpath("row").each do |row|
puts "renaming row to tr"
row.name = 'tr'
end
#frag.xpath("tr/ent").each do |ent|
puts "renaming ent to td"
ent.name = 'td'
end
#frag.xpath("tnote").each do |tfoot|
puts "moving tnote"
tfoot.add_next_sibling('tnote')
end
end
end
Obviously, the last block with the tnote is wrong, but I'm stumped on how to tack that node(s) on to the end of #frag.
I'd be grateful for any nudges in the right direction; the Nokogiri tutorial and cheatsheet just don't make any sense to me.

Answer 1

Three hours after posting, the obvious (now that I see it) answer smacks me upside the head...
#frag.xpath("tnote").each do |tfoot|
puts "moving tnote"
tfoot.parent.add_next_sibling(tfoot).name = 'div'
end
Hope this helps someone else.