我正在编译以下乳胶文件：
\documentclass{article}
\begin{document}
$\begin{array}{c}
1\\
2
\end{array}$
\end{document}
通过 TeXlive 2023 编译以上内容，截至最新 (2023 年 6 月 14 日)
make4ht test.tex "mathml"
输出test.html仅包含表的第一行。
答案1
这是 中的一个错误make4ht。它会自动清除 TeX4ht 生成的 MathML 代码中的一些常见问题。其中之一是 中虚假的空最后一行array。在这种情况下，代码错误地认为第二行为空，并将其删除。
您可以将此修复文件保存为domfilters/make4ht-mathmlfixes.lua文档目录中的文件，或者安装开发版本制作4小时。
local log = logging.new("mathmlfixes")
-- <mglyph> should be inside <mi>, so we don't process it
-- even though it is a token element
local token = {"mi", "mn", "mo", "mtext", "mspace", "ms"}
local token_elements = {}
for _, tok in ipairs(token) do token_elements[tok] = true end
-- helper functions to support MathML elements with prefixes (<mml:mi> etc).
--
local function get_element_name(el)
-- return element name and xmlns prefix
local name = el:get_element_name()
if name:match(":") then
local prefix, real_name = name:match("([^%:]+):?(.+)")
return real_name, prefix
else
return name
end
end
local function get_attribute(el, attr_name)
-- attributes can have the prefix, but sometimes they don't have it
-- so we need to catch both cases
local _, prefix = get_element_name(el)
prefix = prefix or ""
return el:get_attribute(attr_name) or el:get_attribute(prefix .. ":" .. attr_name)
end
local function get_new_element_name(name, prefix)
return prefix and prefix .. ":" .. name or name
end
local function update_element_name(el, name, prefix)
local newname = get_new_element_name(name, prefix)
el._name = newname
end
local function create_element(el, name, prefix)
return el:create_element(newname)
end
local function is_token_element(el)
local name, prefix = get_element_name(el)
return token_elements[name], prefix
end
local function fix_token_elements(el)
-- find token elements that are children of other token elements
if is_token_element(el) then
local parent = el:get_parent()
local is_parent_token, prefix = is_token_element(parent)
if is_parent_token then
-- change top element in nested token elements to mstyle
update_element_name(parent, "mstyle", prefix)
end
end
end
local function fix_nested_mstyle(el)
-- the <mstyle> element can be child of token elements
-- we must exterminate it
local el_name = get_element_name(el)
if el_name == "mstyle" then
local parent = el:get_parent()
if is_token_element(parent) then
-- if parent doesn't have the mathvariant attribute copy it from <mstyle>
if not parent:get_attribute("mathvariant") then
local mathvariant = el:get_attribute("mathvariant")
parent._attr = parent._attr or {}
parent:set_attribute("mathvariant", mathvariant)
end
-- copy the contents of <mstyle> to the parent element
parent._children = el._children
end
end
end
local function fix_mathvariant(el)
-- set mathvariant of <mi> that is child of <mstyle> to have the same value
local function find_mstyle(x)
-- find if element has <mstyle> parent, and its value of mathvariant
if not x:is_element() then
return nil
elseif get_element_name(x) == "mstyle" then
return x:get_attribute("mathvariant")
else
return find_mstyle(x:get_parent())
end
end
if get_element_name(el) == "mi" then
-- process only <mi> that have mathvariant set
local oldmathvariant = el:get_attribute("mathvariant")
if oldmathvariant then
local mathvariant = find_mstyle(el:get_parent())
if mathvariant then
el:set_attribute("mathvariant", mathvariant)
end
end
end
end
local function contains_only_text(el)
-- detect if element contains only text
local elements = 0
local text = 0
local children = el:get_children() or {}
for _ , child in ipairs(children) do
if child:is_text() then text = text + 1
elseif child:is_element() then elements = elements + 1
end
end
return text > 0 and elements == 0
end
-- check if <mstyle> element contains direct text. in that case, add
-- <mtext>
local function fix_missing_mtext(el)
if el:get_element_name() == "mstyle" and contains_only_text(el) then
-- add child <mtext>
log:debug("mstyle contains only text: " .. el:get_text())
-- copy the current mode, change it's element name to mtext and add it as a child of <mstyle>
local copy = el:copy_node()
copy._name = "mtext"
copy._parent = el
el._children = {copy}
end
end
local function is_radical(el)
local radicals = {msup=true, msub=true, msubsup=true}
return radicals[el:get_element_name()]
end
local function get_mrow_child(el)
local get_first = function(x)
local children = x:get_children()
return children[1]
end
local first = get_first(el)
-- either return first child, and if the child is <mrow>, return it's first child
if first and first:is_element() then
if first:get_element_name() == "mrow" then
return get_first(first), first
else
return first
end
end
end
local function fix_radicals(el)
if is_radical(el) then
local first_child, mrow = get_mrow_child(el)
-- if the first child is only one character long, it is possible that there is a problem
if first_child and string.len(first_child:get_text()) == 1 then
local name = first_child:get_element_name()
local siblings = el:get_siblings()
local pos = el:find_element_pos()
-- it doesn't make sense to do any further processing if the element is at the beginning
if pos == 1 then return end
if name == "mo" then
for i = pos, 1,-1 do
end
end
end
end
end
-- put <mrow> as child of <math> if it already isn't here
local allowed_top_mrow = {
math=true
}
local function top_mrow(math)
local children = math:get_children()
local put_mrow = false
-- don't process elements with one or zero children
-- don't process elements that already are mrow
local parent = math:get_parent()
local parent_name
if parent then parent_name = get_element_name(parent) end
local current_name, prefix = get_element_name(math)
if #children < 2 or not allowed_top_mrow[current_name] or current_name == "mrow" or parent_name == "mrow" then return nil end
local mrow_count = 0
for _,v in ipairs(children) do
if v:is_element() and is_token_element(v) then
put_mrow = true
-- break
elseif v:is_element() and get_element_name(v) == "mrow" then
mrow_count = mrow_count + 1
end
end
if not put_mrow and get_element_name(math) == "math" and mrow_count == 0 then
-- put at least one <mrow> to each <math>
put_mrow = true
end
if put_mrow then
local newname = get_new_element_name("mrow", prefix)
local mrow = math:create_element(newname)
for _, el in ipairs(children) do
mrow:add_child_node(el)
end
math._children = {mrow}
end
end
local function get_fence(el, attr, form)
-- convert fence attribute to <mo> element
-- attr: open | close
-- form: prefix | postfix
local char = el:get_attribute(attr)
local mo
if char then
local name, prefix = get_element_name(el)
local newname = get_new_element_name("mo", prefix)
mo = el:create_element(newname, {fence="true", form = form})
mo:add_child_node(mo:create_text_node(char))
end
return mo
end
local function fix_mfenced(el)
-- TeX4ht uses in some cases <mfenced> element which is deprecated in MathML.
-- Firefox doesn't support it already.
local name, prefix = get_element_name(el)
if name == "mfenced" then
-- we must replace it by <mrow><mo>start</mo><mfenced children...><mo>end</mo></mrow>
local open = get_fence(el, "open", "prefix")
local close = get_fence(el, "close", "postfix")
-- there can be also separator attribute, but it is not used in TeX4ht
-- change <mfenced> to <mrow> and remove all attributes
local newname = get_new_element_name("mrow", prefix)
el._name = newname
el._attr = {}
-- open must be first child, close needs to be last
if open then el:add_child_node(open, 1) end
if close then el:add_child_node(close) end
end
end
local function is_fence(el)
return get_element_name(el) == "mo" and el:get_attribute("fence") == "true"
end
local function fix_mo_to_mfenced(el)
-- LibreOffice NEEDS <mfenced> element. so we need to convert <mrow><mo fence="true">
-- to <mfenced>. ouch.
if is_fence(el) then
local parent = el:get_parent()
local open = el:get_text():gsub("%s*", "") -- convert mo content to text, so it can be used in
-- close needs to be the last element in the sibling list of the current element
local siblings = el:get_siblings()
el:remove_node() -- we don't need this element anymore
local close
for i = #siblings, 1, -1 do
last = siblings[i]
if last:is_element() then
if is_fence(last) then -- set close attribute only if the last element is fence
close = last:get_text():gsub("%s*", "")
last:remove_node() -- remove <mo>
end
break -- break looping over elements once we find last element
end
end
-- convert parent <mrow> to <mfenced>
local _, prefix = get_element_name(parent)
local newname = get_new_element_name("mfenced", prefix)
parent._name = newname
parent._attr = {open = open, close = close}
end
end
local function fix_numbers(el)
-- convert <mn>1</mn><mo>.</mo><mn>3</mn> to <mn>1.3</mn>
if get_element_name(el) == "mn" then
local n = el:get_sibling_node(1)
-- test if next element is <mo class="MathClass-punc">.</mo>
if n and n:is_element()
and get_element_name(n) == "mo"
and get_attribute(n, "class") == "MathClass-punc"
and n:get_text() == "."
then
-- get next element and test if it is <mn>
local x = el:get_sibling_node(2)
if x and x:is_element()
and get_element_name(x) == "mn"
then
-- join numbers and set it as text content of the current element
local newnumber = el:get_text() .. "." .. x:get_text()
log:debug("Joining numbers: " .. newnumber)
el._children = {}
local newchild = el:create_text_node(newnumber)
el:add_child_node(newchild)
-- remove elements that hold dot and decimal part
n:remove_node()
x:remove_node()
end
end
end
end
local function just_operators(list)
-- count <mo> and return true if list contains just them
local mo = 0
for _, x in ipairs(list) do
if get_element_name(x) == "mo" then mo = mo + 1 end
end
return mo
end
local function fix_operators(x)
-- change <mo> elements that are only children of any element to <mi>
-- this fixes issues in LibreOffice with a^{*}
-- I hope it doesn't introduce different issues
-- process only <mo>
local el_name, prefix = get_element_name(x)
if el_name ~= "mo" then return nil end
local siblings = x:get_siblings()
-- test if current element list contains only <mo>
if just_operators(siblings) == #siblings then
if #siblings == 1 then
if not x:get_attribute("stretchy") then
-- one <mo> translates to <mtext>
local newname = get_new_element_name("mtext", prefix)
x._name = newname
log:debug("changing one <mo> to <mtext>: " .. x:get_text())
-- I think we should use <mi>, but LO incorrectly renders it in <msubsup>,
-- even if we use the mathvariant="normal" attribute. <mtext> works, so
-- we use that instead.
-- x:set_attribute("mathvariant", "normal")
end
else
-- multiple <mo> translate to <mtext>
local text = {}
for _, el in ipairs(siblings) do
text[#text+1] = el:get_text()
end
-- replace first <mo> text with concetanated text content
-- of all <mo> elements
x._children = {}
local newtext = table.concat(text)
local text_el = x:create_text_node(newtext)
log:debug("changing <mo> to <mtext>: " .. newtext)
x:add_child_node(text_el)
-- change <mo> to <mtext>
local newname = get_new_element_name("mtext", prefix)
x._name = newname
-- remove subsequent <mo>
for i = 2, #siblings do
siblings[i]:remove_node()
end
end
end
end
local function is_last_element(el)
local siblings = el:get_siblings()
-- return true only if the current element is the last in the parent's children
for i = #siblings, 1, -1 do
local curr = siblings[i]
if curr == el then
return true
elseif curr:is_element() then
return false
end
end
return false
end
local function is_empty_row(el)
-- empty row should contain only one <mtd>
local count = 0
if el:get_text():match("^%s*$") then
for _, child in ipairs(el:get_children()) do
if child:is_element() then count = count + 1 end
end
else
-- row is not empty if it contains any text
return false
end
-- if there is one or zero childrens, then it is empty row
return count < 2
end
local function delete_last_empty_mtr(el)
-- arrays sometimes contain last empty row, which causes rendering issues,
-- so we should remove them
local el_name, prefix = get_element_name(el)
if el_name == "mtr"
and get_attribute(el, "class") == "array-row"
and is_last_element(el)
and is_empty_row(el)
then
el:remove_node()
end
end
return function(dom)
dom:traverse_elements(function(el)
if settings.output_format ~= "odt" then
-- LibreOffice needs <mfenced>, but Firefox doesn't
fix_mfenced(el)
else
fix_mo_to_mfenced(el)
end
fix_radicals(el)
fix_token_elements(el)
fix_nested_mstyle(el)
fix_missing_mtext(el)
fix_numbers(el)
fix_operators(el)
fix_mathvariant(el)
top_mrow(el)
delete_last_empty_mtr(el)
end)
return dom
end
这是使用固定过滤器的结果：
