Project structure

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< The ConTeXt Way | Structurals >

Introduction

ConTeXt knows no document classes (as LaTeX does). You can define your layout yourself. If you use the same layout for several products, save it as an environment file.

How to split up a large project, say a book, in several handy parts? – Use ConTeXt's project management facilities.

  • a project links one or more products to their environment
  • a product contains several components
  • an environment defines the common layout (etc.) of a project

The environment could also contain different versions of the layout, e.g. print and screen (like Pragma's manuals) or final and correction etc.

Example 1: Magazine

  • project: magazine
  • product: one volume of the magazine
  • component: a single article

Example 2: Book

  • project: a series of books
  • product: one book
  • component: part or chapter

Project-structure.png

If you tex (compile) one single component (e.g. a chapter of a book) or product (e.g. one volume of a magazine), the environment file of the project is used.

In addition, you have to keep in mind that when compiling a product or component file, ConTeXt goes "up" to the project file and compiles everything it finds in there that is not a \product (e.g. table of content, sectioning commands, text, \component etc.). So all the things on project level have to be put inside a \product, otherwise they will show up in the individual components (or products), too. That also makes it problematic to use \component directly inside a project file, i.e. you have to use \product, you can't skip it.

While you can compile ("tex") products and single components, the project is not intended for compiling; trying might lead to infinite inclusion loops and the error message "TeX capacity exceeded".

File and directory setup

Naming conventions

Hraban uses and suggests the following naming conventions

  • project_foo
  • prd_foo
  • c_foo
  • env_foo

There's a Python script contextproject.py at Hraban's github repository to help creating the files (.ini files can be used for initial content). This functionality would be nice to be integrated in any editor supporting ConTeXt...

Example files

Project

\startproject project_mymag
\environment env_mymag % only mentioned here!

\product prd_year2004-01
\product prd_year2004-02
\product prd_year2004-03
\product prd_year2004-04

\stopproject

Environment

\startenvironment env_mymag

\setuplayout[...]
% all setups...

\stopenvironment

Product

\startproduct prd_year2004-01
\project project_mymag

\component c_editorial
\component c_article01
\component c_article_by_me
% ...

\stopproduct

Component

\startcomponent c_editorial
\product prd_year2004-01 % but you can use it in other products anyway

\title{Editorial}

Dear reader...

\stopcomponent

Subdirectories

If you keep all files in one directory, it tends to get confusing. Here’s a structured example where we keep all parts of one product together:

 env_mymag.tex
 project_mymag.tex
 2011-01/prd_issue2011-01.tex
 2011-02/prd_issue2011-02.tex
 2011-03/prd_issue2011-03.tex
 ...
 2011-03/c_editorial.tex
 2011-03/c_article1.tex
 ...
 2011-03/img/author1.jpg
 ...
 general_img/logo.pdf
 ...

Environment

\startenvironment env_mymag
\project project_mymag

...

% where \product and \component look for TeX input files
\usepath[{2011-01,2011-02,2011-03}]

% where to look for images
\doifmodeelse{*product}
 {\setupexternalfigures[directory={../general_img}]}
 {\setupexternalfigures[directory={../general_img, img}]}

...
\stopenvironment

Product

\startproduct prd_issue2011-01
\project project_mymag
\environment env_mymag

\component c_editorial
\component c_article1
...

\stopproduct

ConTeXt automatically looks into parent directories.

Command behaviour

Within a \start...\stop... environment, project, product, and environment definition files are loaded only once, while component files are loaded at every mention. In addition, certain loading commands are ignored inside certain environments -- for example, it makes no sense to load a \component inside a \startenvironment block. The table below gives an overview.

\project \environment \product \component
\starttext once at every mention
\startproject once once
\startenvironment once
\startproduct once once at every mention
\startcomponent once once at every mention

See also

Hans Hagen (2011) Project Structure, ConTeXt magazine #1101.