subfiles not detecting draft mode

Question

specs: win7x64, miktex, texstudio

folder structure:

root/
 - main.tex
 - text.tex

I get expected wider left margin in main.tex:

\documentclass[draft]{article}
\usepackage{blindtext} % accessories
\usepackage{showframe} % accessories

\usepackage{subfiles}
\usepackage{geometry}
\usepackage{ifdraft}
    \ifdraft{\geometry{left=6cm, right=1cm, vmargin={2.5cm,3cm}, marginparwidth=5.5cm}}
            {\geometry{left=2.7cm, right=2.7cm, top=2.7cm, bottom=2.7cm}}

\begin{document}
\section{Lorem}
    \blindtext
\subfile{text}    
\end{document}

However, when I compile text.tex on its own, it does not pick the draft mode:

\documentclass[main.tex]{subfiles}
\begin{document}
\section{Text}
    \blindtext
\end{document}

The left margin is just the normal width.

QUESTION Any ideas on how I can keep this conditional layout for single chapters?

I also use the \usepackage[obeyDraft]{todonotes}, to have notes in that left margin which will disappear under the final mode.

Answer 1

Add

\makeatletter
\def\@classoptionslist{draft}
\makeatother

before the \documentclass line (while canceling out the explicit 'draft' option from your class declaration) in the main.tex to make sure that the draft option is active also in your subfile text.tex. The following one-liner is equivalent:

\bgroup\makeatletter\gdef\@classoptionslist{draft}\egroup

Obviously, once you want to change to 'final' just delete or comment out that line.

---

Alternative

You can also specify the 'draft' option directly in your subfile:

\documentclass[draft,main.tex]{subfiles}

It will be discarded anyway when the subfile gets included back to main.tex (see \skip@preamble in subfiles.sty).

Important: Make sure that the parent file name is the last option as subfiles.cls lets the internal macro that saves the parents file name, i.e. \preamble@file, to the \CurrentOption inside a starred option declaration.

_{Tested with version 1.1 of subfiles from 2012/05/23.}

Answer 2

One more alternative would be to modify subfiles.cls to reset \@classoptionslist before calling LoadClass. Indeed, LoadClass checks that this variable is empty before setting it to the list of options. See this answer for a candidate implementation.