編輯

Question 1

standalone此解決方案啟用包含的檔案的目標語法tikzpicture，但在主檔案中使用自訂命令。

更具體地說，conditionally是一個採用單一強制參數的環境。

參數應包含一個用於標識內容的簡單標記/標籤。
在範例中，這用作 a 的一部分tikzpicture，但解決方案不依賴於此。相同的機制同樣可以用於包含精選的引用或任意程式碼片段。

\flowconditional[<key-value list>]{<filename>}在主文檔中用於透過標籤/標籤從中選擇片段<filename>。

目前僅定義了一個鍵，enable.
enable採用逗號分隔的數值清單。
<filename>每個值應該是或中的標記/標籤*，其中*指示應包含所有可用代碼。
但是，此要求並未強制執行：如果傳遞給的值enable未在中定義filename，則該值將被靜默忽略。

鑑於 OP 的圖形檔案名為\jobname-fig.tex，我們可以編寫

\flowconditionalpic[enable=*]{\jobname-fig}

\flowconditionalpic[enable=detour]{\jobname-fig}

\flowconditionalpic[enable={detour,longer-detour}]{\jobname-fig}

產生目標行為。

可以使用相同的框架來包含或不包含tabular環境（儘管包含行集需要更多的工作）。例如，

\begin{table}
  \caption{Tables rather than pictures}
  \flowconditional[enable=tab1]{\jobname-tab}
  \flowconditional[enable=tab2]{\jobname-tab}
\end{table}

\begin{table}
  \caption{Order is irrelevant}
  \flowconditional[enable=*]{\jobname-tab}
  \flowconditional[enable={tab2,tab1}]{\jobname-tab}
\end{table}

其中\jobname-tab.tex包含

\documentclass{standalone}
\usepackage{array}
\usepackage{booktabs}
\begin{document}
\sffamily
\begin{conditionally}{tab1}
  \begin{tabular} {ll}
    \toprule
    \bfseries Column 1 & \bfseries Column 2 \\
    \midrule
    Row 1 & Cell A \\
    \bottomrule
  \end{tabular}
\end{conditionally}
\begin{conditionally}{tab2}
  \begin{tabular} {ll}
    \toprule
    \bfseries Column 1 & \bfseries Column 2 \\
    \midrule
    Row 1 & Cell A \\
    Row 2 & Cell B \\
    \bottomrule
  \end{tabular}
\end{conditionally}
\end{document}

完整程式碼：

\begin{filecontents}[overwrite]{\jobname-fig.tex}
\documentclass{standalone}

\usepackage{tikz}

\begin{document}
\begin{tikzpicture}  
  \pgfmathsetmacro{\myRadius}{2} 
  \coordinate (loop-start) at (-170:\myRadius);  
  \draw[->,line width=7pt,]
  (loop-start)
  arc (-170:170:\myRadius)
  coordinate[pos=0.75] (detour-start)
  coordinate[pos=0.25] (detour-end)
  coordinate[pos=0.27] (detour-end-2)
  ;  
  \begin{conditionally}{detour}
    \draw[
    ->,
    line width=3pt,
    red,
    ] (detour-start) to[out=160, in=220, distance=6cm] (detour-end);
  \end{conditionally}  
  \begin{conditionally}{longer-detour}
    \draw[
    ->,
    line width=3pt,
    red,
    ] (detour-start) to[out=45, in=-30, distance=10cm] (detour-end-2);
  \end{conditionally}
\end{tikzpicture}
\end{document}
\end{filecontents}
\begin{filecontents}[overwrite]{\jobname-tab.tex}
\documentclass{standalone}
\usepackage{array}
\usepackage{booktabs}
\begin{document}
\sffamily
\begin{conditionally}{tab1}
  \begin{tabular} {ll}
    \toprule
    \bfseries Column 1 & \bfseries Column 2 \\
    \midrule
    Row 1 & Cell A \\
    \bottomrule
  \end{tabular}
\end{conditionally}
\begin{conditionally}{tab2}
  \begin{tabular} {ll}
    \toprule
    \bfseries Column 1 & \bfseries Column 2 \\
    \midrule
    Row 1 & Cell A \\
    Row 2 & Cell B \\
    \bottomrule
  \end{tabular}
\end{conditionally}
\end{document}
\end{filecontents}

\documentclass{article}
% ateb: https://tex.stackexchange.com/a/705487/ addaswyd o gwestiwn Flow: https://tex.stackexchange.com/q/705458/
\usepackage[subpreambles]{standalone}
\usepackage{tikz}
\ExplSyntaxOn
\bool_new:N \l_flow_condition_bool
\bool_set_false:N \l_flow_condition_bool
\keys_define:nn { flow }
{
  enable .clist_set:N = \l_flow_conditions_clist,
  enable .initial:n = ,
  enable .default:n = ,
}
\NewDocumentEnvironment { conditionally } { m +b }
{
  \clist_if_in:NnT \l_flow_conditions_clist { #1 }
  { \bool_set_true:N \l_flow_condition_bool } 
  \clist_if_in:NnT \l_flow_conditions_clist { * }
  { \bool_set_true:N \l_flow_condition_bool } 
  \bool_if:NT \l_flow_condition_bool { #2 }
}{  }
\NewDocumentCommand \flowconditional { O {} m }
{
  \group_begin:
    \keys_set:nn { flow } { #1 }
    \includestandalone { #2 }
  \group_end:
}
\ExplSyntaxOff

\begin{document}
\flowconditional[enable=*]{\jobname-fig}

\flowconditional[enable=detour]{\jobname-fig}

\flowconditional[enable={detour,longer-detour}]{\jobname-fig}


\begin{table}
  \caption{Tables rather than pictures}
  \flowconditional[enable=tab1]{\jobname-tab}
  \flowconditional[enable=tab2]{\jobname-tab}
\end{table}

\begin{table}
  \caption{Order is irrelevant}
  \flowconditional[enable=*]{\jobname-tab}
  \flowconditional[enable={tab2,tab1}]{\jobname-tab}
\end{table}

\end{document}

編輯

下面新增一個附加鍵standalone options。最初，該值設定為mode = tex。使用不帶值的鍵將會清空選項。使用帶有值的鍵會將選項設定為該值。在下面的範例中，初始值適用於大多數情況，用於angle=90示範更改選項的效果。

\documentclass{article}
% ateb: https://tex.stackexchange.com/a/705487/ addaswyd o gwestiwn Flow: https://tex.stackexchange.com/q/705458/
\usepackage[subpreambles]{standalone}
\usepackage{tikz}
\ExplSyntaxOn
\bool_new:N \l_flow_condition_bool
\bool_set_false:N \l_flow_condition_bool
\keys_define:nn { flow }
{
  enable .clist_set:N = \l_flow_conditions_clist,
  enable .initial:n = ,
  enable .default:n = ,
  standalone ~ options .tl_set:N = \l_flow_standalone_tl,
  standalone ~ options .default:n = ,
  standalone ~ options .initial:n = {mode = tex},
}
\NewDocumentEnvironment { conditionally } { m +b }
{
  \clist_if_in:NnT \l_flow_conditions_clist { #1 }
  { \bool_set_true:N \l_flow_condition_bool } 
  \clist_if_in:NnT \l_flow_conditions_clist { * }
  { \bool_set_true:N \l_flow_condition_bool } 
  \bool_if:NT \l_flow_condition_bool { #2 }
}{  }
\NewDocumentCommand \flowconditional { O {} m }
{
  \group_begin:
    \keys_set:nn { flow } { #1 }
    \flow_includestandalone:Vn \l_flow_standalone_tl { #2 }
  \group_end:
}
\cs_new_protected:Nn \flow_includestandalone:nn
{
  \includestandalone [ #1 ] { #2 }
}
\cs_generate_variant:Nn \flow_includestandalone:nn { Vn }
\ExplSyntaxOff

\begin{document}
\flowconditional[enable=*]{\jobname-fig}

\flowconditional[enable=detour,standalone options={angle=90}]{\jobname-fig}

\flowconditional[enable={detour,longer-detour}]{\jobname-fig}


\begin{table}
  \caption{Tables rather than pictures}
  \flowconditional[enable=tab1]{\jobname-tab}
  \flowconditional[enable=tab2]{\jobname-tab}
\end{table}

\begin{table}
  \caption{Order is irrelevant}
  \flowconditional[enable=*]{\jobname-tab}
  \flowconditional[enable={tab2,tab1}]{\jobname-tab}
\end{table}

\end{document}

Answer