Multi-file latex project, with a title page in hebrew

Question

I have a large LaTeX project (my thesis) with a main TeX file (main.tex) and many subfiles contained in their own sub-directory. All are interrelated with the subfiles package.

Now I want to add a title page to appear on the first page of the compiled pdf file, with hebrew text: To include the thesis title, author name and institution name.

The preponderance of the project is best compiled with pdfLatex, and therefore I wish to stick with this one and not change to XeLaTeX.

I successfully compiled a .tex file that contains hebrew AND english letters (titlepage.tex).

I want titlepage.tex to appear first, and after it all the series of chapter0*.tex files.

Now comes the question - how to compile the project properly?

I tried to import the standalone and import packages to main.tex:

\usepackage[subpreambles=true]{standalone}
\usepackage{import}

and then call for titlepage.tex right after \begin{document}: \usepackage[subpreambles=true]{standalone} \usepackage{import} \begin{docment} \import{./}{titlepage} \end{document}

But nothing compiled - a multitude of errors concerning the standalone.sty file.

Any help?

The hierarchical file structure is as follows:

root folder
├main.tex
├titlepage.tex
└───figures
| │ figure01
│ │ figure02
│ │ figure03
└───subfiles
| │ chapter01
| │ chapter02
| │ chapter03

The main.tex file structure:

\documentclass{tufte-book} % Tufte-book format
\usepackage[utf8]{inputenc} 
\usepackage[english]{babel} % Bibliography
\usepackage{biblatex}
\addbibresource{references.bib}
\usepackage{subfiles} % Best loaded last in the preamble
%%% Document %%%
\begin{document}
\chapter{Chapter 1}
\subfile{subfiles/chapter01}
\chapter{Chapter 2}
\subfile{subfiles/chapter02}
\chapter{Chapter 3}
\subfile{subfiles/chapter03}
\end{document}

The chpater0*.tex files has just the same document preamble as main.tex.

The Hebrew language file, to be used as a title page:

\documentclass{article}
%\usepackage[subpreambles=true]{standalone}
%\usepackage{import}
\usepackage[utf8x]{inputenc} % utf8x for hebrew letters
\usepackage[english,hebrew]{babel}
\selectlanguage{hebrew}
\begin{document}
כיתוב בעברית.
\selectlanguage{english}
English text.
\end{document}

Note: I compile the the project in overleaf.

Answer 1

I am using Overleaf also with multiple subfiles. I use the command \documentclass[main.tex]{subfiles} to import the preamble of the main into the subfiles. Besides \selectlanguage should be used inside the document I think.

Here is my an example inspired by your MWE that worked for me :

main.tex :

\documentclass{tufte-book} % Tufte-book format
\usepackage[utf8x]{inputenc}
\usepackage[main=english, hebrew]{babel}
\usepackage{subfiles} % Best loaded last in the preamble
\newcommand{\onlyinsubfile}[1]{#1}
\newcommand{\notinsubfile}[1]{}
%%% Document %%%
\begin{document}
\renewcommand{\onlyinsubfile}[1]{}
\renewcommand{\notinsubfile}[1]{#1}
\subfile{titlepage}
\chapter{Chapter 1}
\subfile{subfiles/chapter0}
\end{document}

titlepage.tex

\documentclass[main.tex]{subfiles}
\begin{document}
\selectlanguage{hebrew}
כיתוב בעברית.
\selectlanguage{english}
English text.
\end{document}

The functions \onlyinsubfile and \notinsubfile can be used in the subfiles and allow you to execute commands depending if you are trying to compile the standalone subfile or the whole document.

Finally for managing biblatex with hebrew caracter look at this answer Using Biblatex with utf8x