Count Number of Columns in XML

Question

I have successfully loaded XML in LuaLaTeX but how to load XML-Tables?

\documentclass{book}
\usepackage{luacode}
\begin{document}
\begin{luacode*}
local domobject = require "luaxml-domobject"
sample = [[
<datas>
  <arttitle>Quantum vacuum under mixed boundary conditions: the case for curved spacetime</arttitle>
  <table-wrap id="tab1" position="float">
  <label>Table 1ABC.</label>
  <caption id="t1"><p>The large <italic>x</italic> behavior for different <italic>w</italic>.</p></caption>
  <table>
  <colgroup>
  <col align="left"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  </colgroup>
  </table>
  <thead>
  <tr>
  <th>A1</th>
  <th>A2</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>B1</td>
  <td>B2</td>
  </tr>
  </tbody>
  </table-wrap>
</datas>]]
local dom = domobject.parse(sample)
tex.sprint(dom:query_selector("arttitle")[1]:get_text())
\end{luacode*}
\end{document}

It's printing article-title in PDF. How to do number of columns in XML and create in PDF?

score 1 · Accepted Answer · edited Aug 27 '21 at 11:39

Edit:

Here is how this XML file can be transformed to LaTeX and printed in the document. We can utilize the new luaxml-transform library which is present in the development version of LuaXML.

Here is the updated TeX file:

% https://tex.stackexchange.com/a/574004/2891
\documentclass{book}
\usepackage{luacode}
\begin{document}
\begin{luacode*}
local domobject = require "luaxml-domobject"
local transform = require "luaxml-transform"
sample = [[
<datas>
  <arttitle>Quantum vacuum under mixed boundary conditions: the case for curved spacetime</arttitle>
  <table-wrap id="tab1" position="float">
  <label>Table 1ABC.</label>
  <caption id="t1"><p>The large <italic>x</italic> behavior for different <italic>w</italic>.</p></caption>
  <table>
  <colgroup>
  <col align="left"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="char" char="."/>
  </colgroup>
  <thead>
  <tr>
  <th>A1</th>
  <th>A2</th>
  <th>A3</th>
  <th>A4</th>
  <th>A5</th>
  <th>A6</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>B1</td>
  <td>B2</td>
  <td>B3</td>
  <td>B4</td>
  <td>B5</td>
  <td>B6</td>
  </tr>
  </tbody>
  </table>
  </table-wrap>
</datas>]]
local dom = domobject.parse(sample)
local alignments = {left="l", center="c", right="r"}
-- rules for conversion
transform.add_action("p", "%s\n\n")
transform.add_action("italic", "\textit{%s}")
transform.add_action("arttitle", "\noindent{\large\bfseries %s\par\noindent}")
transform.add_action("table-wrap", [[
\begin{table}
%s
\end{table}
]])
transform.add_action("label", "\label{%s}")
transform.add_action("caption", "\caption{%s}")
transform.add_action("table", [[
\begin{tabular}{@{data-columns}}
%s
\end{tabular}
]])
transform.add_action("tr", "%s \\")
transform.add_action("td", "& %s ")
transform.add_action("td:first-child", "%s ")
transform.add_action("th", "& %s ")
transform.add_action("th:first-child", "%s ")
-- get table columns
local function get_columns(tbl)
  local columns = {}
  for _, column in ipairs(tbl:query_selector("col")) do
    -- save column alignment. left is default
    local align = column:get_attribute("align") or "left"
    table.insert(columns, alignments[align])
  end
  return table.concat(columns, " ")
end
for i, tbl in ipairs(dom:query_selector("table")) do
  -- save table columns in table attribute, so it is available in transformation rules
  local columns = get_columns(tbl)
  tbl:set_attribute("data-columns", columns)
end
local converted = transform.process_dom(dom)
print(converted)
transform.print_tex(converted)
\end{luacode*}
\end{document}

In this case, we use the following code to set the tabular columns before the transformation:

-- get table columns
local function get_columns(tbl)
  local columns = {}
  for _, column in ipairs(tbl:query_selector("col")) do
    -- save column alignment. left is default
    local align = column:get_attribute("align") or "left"
    table.insert(columns, alignments[align])
  end
  return table.concat(columns, " ")
end
for i, tbl in ipairs(dom:query_selector("table")) do
  -- save table columns in table attribute, so it is available in transformation rules
  local columns = get_columns(tbl)
  tbl:set_attribute("data-columns", columns)
end

It sets the custom attribute, data-columns, with a value needed for the tabular environment based on the align attribute, like l c c c c c in this case.

The transformation rules are declared like this:

transform.add_action("label", "\\label{%s}")

The first argument is CSS selector that should be transformed. In the easiest case, it is just element name. The second argument is a template that will be used. %s is replaced with the element contents.

transform.add_action("table", [[
\begin{tabular}{@{data-columns}}
%s
\end{tabular}
]])

This more complicated transformation configures the table. @{data-columns} selects the data-columns attribute that we set earlier in the DOM processing function.

transform.add_action("td", "& %s ")
transform.add_action("td:first-child", "%s ")

This is an example of a more specific CSS rule. & characters are appended before table cells, except the first cell in each row.

This is the resulting PDF:

Another edit:

You can use this code as a standalone script to convert XML to LaTeX from the command line, bxmltolatex.lua:

kpse.set_program_name "luatex"
local domobject = require "luaxml-domobject"
local transform = require "luaxml-transform"
-- read input from stdio
local sample = io.read("*all")
local dom = domobject.parse(sample)
-- rules for conversion
transform.add_action("p", "%s\n\n")
transform.add_action("italic", "\textit{%s}")
transform.add_action("arttitle", "\noindent{\large\bfseries %s\par\noindent}")
transform.add_action("table-wrap", [[
\begin{table}
%s
\end{table}
]])
transform.add_action("label", "\label{%s}")
transform.add_action("caption", "\caption{%s}")
transform.add_action("table", [[
\begin{tabular}{@{data-columns}}
%s
\end{tabular}
]])
transform.add_action("tr", "%s \\")
transform.add_action("td", "& %s ")
transform.add_action("td:first-child", "%s ")
transform.add_action("th", "& %s ")
transform.add_action("th:first-child", "%s ")
-- ignore colgroup
transform.add_action("colgroup", "")
-- get table columns
local alignments = {left="l", center="c", right="r"}
local function get_columns(tbl)
  local columns = {}
  for _, column in ipairs(tbl:query_selector("col")) do
    -- save column alignment. left is default
    local align = column:get_attribute("align") or "left"
    table.insert(columns, alignments[align])
  end
  return table.concat(columns, " ")
end
for i, tbl in ipairs(dom:query_selector("table")) do
  -- save table columns in table attribute, so it is available in transformation rules
  local columns = get_columns(tbl)
  tbl:set_attribute("data-columns", columns)
end
local converted = transform.process_dom(dom)
print(converted)

file.xml is:

<datas>
  <arttitle>Quantum vacuum under mixed boundary conditions: the case for curved spacetime</arttitle>
  <table-wrap id="tab1" position="float">
  <label>Table 1ABC.</label>
  <caption id="t1"><p>The large <italic>x</italic> behavior for different <italic>w</italic>.</p></caption>
  <table>
  <colgroup>
  <col align="left"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  </colgroup>
  <thead>
  <tr>
  <th>A1</th>
  <th>A2</th>
  <th>A3</th>
  <th>A4</th>
  <th>A5</th>
  <th>A6</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>B1</td>
  <td>B2</td>
  <td>B3</td>
  <td>B4</td>
  <td>B5</td>
  <td>B6</td>
  </tr>
  </tbody>
  </table>
  </table-wrap>
</datas>

Use it as:

texlua bxmltolatex.lua < file.xml > TransformedLatex.tex

Original answer:

You can use the query_selector on particular elements:

\documentclass{book}
\usepackage{luacode}
\begin{document}
\begin{luacode*}
local domobject = require "luaxml-domobject"
sample = [[
<datas>
  <arttitle>Quantum vacuum under mixed boundary conditions: the case for curved spacetime</arttitle>
  <table-wrap id="tab1" position="float">
  <label>Table 1ABC.</label>
  <caption id="t1"><p>The large <italic>x</italic> behavior for different <italic>w</italic>.</p></caption>
  <table>
  <colgroup>
  <col align="left"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  <col align="center"/>
  </colgroup>
  </table>
  <thead>
  <tr>
  <th>A1</th>
  <th>A2</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>B1</td>
  <td>B2</td>
  </tr>
  </tbody>
  </table-wrap>
</datas>]]
local dom = domobject.parse(sample)
tex.sprint(dom:query_selector("arttitle")[1]:get_text())
tex.sprint("\par")
local function get_columns(tbl)
  return #tbl:query_selector("col")
end
for i, tbl in ipairs(dom:query_selector("table")) do
  tex.sprint("Table: " .. i .. " has " .. get_columns(tbl) .. " columns")
end
\end{luacode*}
\end{document}

The important part is this:

local function get_columns(tbl)
  return #tbl:query_selector("col")
end
for i, tbl in ipairs(dom:query_selector("table")) do
  tex.sprint("Table: " .. i .. " has " .. get_columns(tbl) .. " columns")
end

It processes all tables in your document and it prints the column count calculated by #tbl:query_selector("col") for every table.

This is the result:

Sorry to interrupt, hope the OP wants to create a table output based on his XML tags, excuse me if I'm wrong... — MadyYuvi, Dec 07 '20 at 15:38
@MadyYuvi I am not sure what OP really wants, so I am just answering how I understand it — michal.h21, Dec 07 '20 at 15:54
@michal.h21: It's working fine. Exactly i have need to find the table total no of col elements. How to print all the table of elements in the PDF? — Balaji, Dec 07 '20 at 17:21
@Balaji it is bit more complicated. you will need some kind of XML to LaTeX transformation library like ones I posted in my earlier answers to your posts. I have updated version in the LuaXML development version. — michal.h21, Dec 07 '20 at 22:58
@michal.h21: Okay I understood and would like to modify XML itself. Like <colgroup> need to change <colgroup cols="number of columns here"> (Ex: <colgroup cols="7"). How to do this? — Balaji, Dec 08 '20 at 08:06
@michal.h21: I had tried xmlout = string.gsub(xmlout,"<colgroup>","<colgroup cols=get_columns(tbl)>") and not working... — Balaji, Dec 08 '20 at 08:11
@michal.h21: Amazing michal. It's exactly what i have needed and i will study the luaxml-transform`. Thanks for your help. — Balaji, Dec 08 '20 at 16:36
@Balaji it is still new code that isn't really documented anywhere yet. This is the first public presentation :) — michal.h21, Dec 08 '20 at 16:47
@michal.h21: One small updations. Transformed LaTeX file will store in separate file like (Transformed-LaTeX.TeX) it will useful to find and fix the any bugs. It's possible? — Balaji, Dec 09 '20 at 05:57
@Balaji sure, you can extract just the script and use it from the command line. see the updated answer. — michal.h21, Dec 09 '20 at 08:31
@Balaji please post it as a separate question, I will need to see your bibliography XML. — michal.h21, Mar 16 '21 at 17:52
@michal.h21: How to find the col with char alignment (ex: align="char" char=".")? — Balaji, Aug 27 '21 at 11:28
@Balaji I think it would be best if you could ask a new question for that, it is a separate problem from your original question. — michal.h21, Aug 27 '21 at 11:39
@michal.h21: I have posted new question https://tex.stackexchange.com/questions/612213/table-char-alignment-in-xml — Balaji, Aug 27 '21 at 11:51

Count Number of Columns in XML

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