如何通过附加文档开头的自定义标签生成目录？

Question

这个addtotoc选择有点棘手！

addtotoc={page-number,sectiontype,level,heading,label}的正确用法是addtotoc，

页码必须与选项给出的页码相匹配pages=。

sectiontype 可以是section，subsection等等。
level 是部分级别，即 1 表示section，2 代表subsection等等（照例）
标题是目录中出现的名称
标签是应用于此包含的 pdf 文件的标签（可以留空

和7.pdf已8.pdf生成以下文件（并重命名）

\documentclass{article}

\usepackage{blindtext}

\begin{document}
\section{Beginning \jobname}
\blindtext[50]
\end{document}

这是运行的代码。

\documentclass{article}
\usepackage{pdfpages}
\usepackage{hyperref} % for links in TOC
% https://tex.stackexchange.com/q/56316/13173
\usepackage{fancyhdr}
\renewcommand{\headrulewidth}{0pt} % Werner, remove top margin border
% https://tex.stackexchange.com/a/338919/13173
\usepackage{letltxmacro}
\LetLtxMacro\oldincludepdf\includepdf
\renewcommand{\includepdf}[4][]{%
  \oldincludepdf[pagecommand={‌\thispagestyle{fancy‌}},addtotoc={#4,section,1,#2,#3}, #1]{#2}}

\begin{document}

% TODO add custom labels to TOC 
\tableofcontents
% Pseudocode
% \addcontentsline{toc}{someLabelForPdf}{\listPdfBeginningLabels}

% TODO add here a label/... to the beginning of pdf page such that included in TOC
\includepdf[pages=1,pagecommand=\thispagestyle{plain}]{7.pdf}{firstpage7pdf}{1}
% No reference to the rest
\includepdf[pages=2-,pagecommand=\thispagestyle{plain}]{7.pdf}{remainingpages7pdf}{2}

% TODO reference here
\includepdf[pages=1,pagecommand=\thispagestyle{plain}]{8.pdf}{firstpage8pdf}{1}
% No reference to the rest
\includepdf[pages=2-,pagecommand=\thispagestyle{plain}]{8.pdf}{remainginpages8pdf}{2}

\end{document}

使用键值接口进行更新

\documentclass{article}
\usepackage{xparse}

\ExplSyntaxOn

% Switch to expl3 - Syntax

% Define a storing place for the option values
\prop_new:N \l_leo_option_prop

% keys for the new functionality
\keys_define:nn {LEO} {%
   page .code:n = {\prop_put:Nnn \l_leo_option_prop {page} {#1}},
  section .code:n = {\prop_put:Nnn \l_leo_option_prop {section} {#1}},
  level .code:n = {\prop_put:Nnn \l_leo_option_prop {level} {#1}},
  heading .code:n = {\prop_put:Nnx \l_leo_option_prop {heading} {#1}},
  label .code:n = {\prop_put:Nnn \l_leo_option_prop {label} {#1}},
}

%  Keys setting 
\cs_new:Npn \SetupPdfInclude #1 {%
  \keys_set:nn {LEO} {#1}
}

% Get some key value 
\cs_new:Npn \retrieveoption #1 {%
  \prop_item:Nn \l_leo_option_prop {#1}
}

\ExplSyntaxOff


\usepackage{pdfpages}
\usepackage{hyperref} % for links in TOC
% https://tex.stackexchange.com/q/56316/13173
\usepackage{fancyhdr}
\renewcommand{\headrulewidth}{0pt} % Werner, remove top margin border
% https://tex.stackexchange.com/a/338919/13173
\usepackage{letltxmacro}


\makeatletter
\LetLtxMacro\pdfpages@@includepdf\includepdf

\RenewDocumentCommand{\includepdf}{O{}mo}{%
  \begingroup
  \IfValueTF{#3}{% Is there a 3rd argument? Yes
    % Process the keys for the \includepdf first in order to get the value of 'pages=...' option
    % This is stored to \AM@pagestemp (see pdfpages.sty)
    \setkeys{pdfpages}{#1}%
    \SetupPdfInclude{label={label#2\AM@pagestemp},page={\AM@pagestemp}, heading={#2},#3}
    % Call the old command with the options for addtotoc
    \pdfpages@@includepdf[pagecommand={\thispagestyle{fancy}},addtotoc={\retrieveoption{page},\retrieveoption{section},\retrieveoption{level},\retrieveoption{heading},\retrieveoption{label}},#1]{#2}
  }{% No, no 3rd. argument}
    \pdfpages@@includepdf[pagecommand={\thispagestyle{fancy}},#1]{#2}
  }%
  \endgroup% Prevent leaking of key values to the next call of the command
}
\makeatother



% Set some default values
\SetupPdfInclude{page=1,section=section,level=1}

\begin{document}

% TODO add custom labels to TOC 
\tableofcontents
% Pseudocode
% \addcontentsline{toc}{someLabelForPdf}{\listPdfBeginningLabels}

\includepdf[pagecommand=\thispagestyle{plain}]{7.pdf}[label=firstpage7pdf]
\includepdf[pages=2-,pagecommand=\thispagestyle{plain}]{7.pdf}[page=2,heading={\retrieveoption{heading} continued}]

\includepdf[pages=1,pagecommand=\thispagestyle{plain}]{8.pdf}[label=firstpage8pdf]
\includepdf[pages=2-,pagecommand=\thispagestyle{plain}]{8.pdf}[heading={\retrieveoption{heading} continued}]

\end{document}

几个键值对应到addtotoc选项中的条目，这样做的好处是，精确的顺序是由代码完成的，而不是通过使用规范。

默认情况下heading将使用强制参数\includepdf，即#2。

Answer 1