Note

This version of the guide covers the new PHP-based rendering of Documentation with the TYPO3 Documentation theme.

If the project you are looking at has a file Documentation/guides.xml it is using the new rendering.

Otherwise, consider to migrate the Documentation or head over to the legacy version of this guide: How to document, Sphinx based.

Code blocks with syntax highlighting

Quick Reference

A code block consists of a code-block directive and the actual code indented by four spaces for consistency with other code bases.

A code block can have one or more options. To make orientation in code examples easier try to always add a :caption: with the path and name of the file where the example should go:

Documentation/MyDocs.rst

..  code-block:: php
    :caption: EXT:site_package/Configuration/TCA/Overrides/sys_template.php

    /**
     * Add default TypoScript (constants and setup)
     */
    \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
         'site_package',
         'Configuration/TypoScript',
         'Site Package'
    );

EXT:site_package/Configuration/TCA/Overrides/sys_template.php

/**
 * Add default TypoScript (constants and setup)
 */
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
     'site_package',
     'Configuration/TypoScript',
     'Site Package'
);

Always use syntactically correct code in a code block.

Use placeholders in angle brackets (<placeholder-name>) to refer to a place in the code where the exact value is not important.

Code block directive

A code block has the following syntax:

Documentation/MyDocs.rst

..  code-block:: <language>
    :caption: <caption>
    <options>

    <code>

There must be a newline between the options and the code. There must not be a newline between the directive line and options or within options. Otherwise the rendering will fail.

<language>

The language of the code-block. We commonly use the following: php, typoscript (also for TSconfig), yaml, javascript, html (also for Fluid), shell, xml, plaintext.

See all available languages

<caption>

To make orientation in code examples easier try to always add a caption with the name of the file where the example should go. If the code should be manually entered in the TYPO3 backend explain where it should go there.

<options>

The following options may be used, all options are optional, but caption is highly recommended:

..  code-block:: <language>
    :caption: <caption>
    :linenos:
    :lineno-start: <start-number>
    :emphasize-lines: <emphasized-line-numbers>
    :name: <reference-label>

linenos: Show line numbers.
lineno-start: Start line numbers with <start-number>.
emphasize-lines: <emphasized-line-numbers> contains a comma separated list of line numbers to be emphasized.
name: Set a <reference-label>. This label can be used to link from any given text to the specific code block. The name needs to be unique within one manual.

See also the official sphinx documentation on code-blocks.

Examples

A simple code block with syntax highlighting

Documentation/MyDocs.rst

..  code-block:: php
    :caption: EXT:site_package/Configuration/TCA/Overrides/sys_template.php

    /**
     * Add default TypoScript (constants and setup)
     */
    \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
         'site_package',
         'Configuration/TypoScript',
         'Site Package'
    );

EXT:site_package/Configuration/TCA/Overrides/sys_template.php

/**
 * Add default TypoScript (constants and setup)
 */
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
     'site_package',
     'Configuration/TypoScript',
     'Site Package'
);

Code block with line numbers and highlighting of one line
    

    

        Documentation/MyDocs.rst
    
..  code-block:: php
    :caption: EXT:site_package/Configuration/TCA/Overrides/sys_template.php
    :linenos:
    :emphasize-lines: 4, 7

    /**
     * Add default TypoScript (constants and setup)
     */
    \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
         'site_package',
         'Configuration/TypoScript',
         'Site Package'
    );        
        Copied!
    

        EXT:site_package/Configuration/TCA/Overrides/sys_template.php
    
/**
 * Add default TypoScript (constants and setup)

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile(
     'site_package',
     'Configuration/TypoScript',
     'Site Package'
        
        Copied!
    

Use code blocks containing diffs

To emphasize changes that should be made:

Documentation/MyDocs.rst

..  code-block:: diff
    :caption: ext_localconf.php.diff

     <?php

    -defined('TYPO3_MODE') or die();
    +defined('TYPO3') or die();

ext_localconf.php.diff

 <?php

-defined('TYPO3_MODE') or die();
+defined('TYPO3') or die();

Hint

You can use diff tools such as the bartlweb diff file generator. Make sure to use the type unified context

Show a directory tree

To display an expandable directory tree, use the directive '.. directory-tree::'.

Documentation/MyDocs.rst

..  code-block:: none
    :caption: Page tree of directory :file:`vendor/composer`

    $ tree vendor/composer
    ├── ClassLoader.php
    ├── LICENSE
    ├── autoload_classmap.php
    ├── ...
    └── installed.json

Page tree of directory vendor/composer

$ tree vendor/composer
├── ClassLoader.php
├── LICENSE
├── autoload_classmap.php
├── ...
└── installed.json

Use syntactically correct code

Attention

Please: No syntax errors!

Syntax highlighting only works if the lexer can parse the code without errors. In other words: If there's a syntax error in the code the highlighting will not work.

Documentation/MyDocs.rst

..  code-block:: php

    $a = array(
        'one' => 1,
        // ...
    );

Documentation/MyDocs.rst

..  code-block:: php

    $a = array(
        'one' => 1,
        ...
    );

Available languages

The following languages are supported. They can be used in a code-block and a literalinclude directive.

1c
abnf
accesslog
actionscript
ada
angelscript
apache
applescript
arcade
arduino
armasm
asciidoc
aspectj
autohotkey
autoit
avrasm
awk
axapta
bash
basic
bnf
brainfuck
cal
capnproto
ceylon
clean
clojure
clojure-repl
cmake
coffeescript
coq
cos
cpp
crmsh
crystal
cs
csp
css
d
dart
delphi
diff
django
dns
dockerfile
dos
dsconfig
dts
dust
ebnf
elixir
elm
erb
erlang
erlang-repl
excel
fix
flix
fortran
fsharp
gams
gauss
gcode
gherkin
glsl
gml
go
golo
gradle
groovy
haml
handlebars
haskell
haxe
hsp
htmlbars
http
hy
inform7
ini
irpf90
isbl
java
javascript
jboss-cli
json
julia
julia-repl
kotlin
lasso
ldif
leaf
less
lisp
livecodeserver
livescript
llvm
lsl
lua
makefile
markdown
mathematica
matlab
maxima
mel
mercury
mipsasm
mizar
mojolicious
monkey
moonscript
n1ql
nginx
nimrod
nix
nsis
objectivec
ocaml
openscad
oxygene
parser3
perl
pf
pgsql
php
plaintext
pony
powershell
processing
profile
prolog
properties
protobuf
puppet
purebasic
python
q
qml
r
reasonml
rib
roboconf
routeros
rsl
rst
ruby
ruleslanguage
rust
sas
scala
scheme
scilab
scss
shell
smali
smalltalk
sml
sqf
sql
stan
stata
step21
stylus
subunit
swift
taggerscript
tap
tcl
tex
thrift
tp
twig
typescript
typoscript
vala
vbnet
vbscript
vbscript-html
verilog
vhdl
vim
x86asm
xl
xml
xquery
yaml
zephir

Literalinclude

A drawback of code blocks is that most editors cannot properly highlight or indent code within code blocks. The directive literalinclude enables you to store longer code blocks in an external file with the proper file extension.

The literalinclude directive imports the file and displays its content as code block.

Documentation/SiteConfiguration/Index.rst

..  literalinclude:: /_CodeSnippets/LiteralIncludes/example.yaml
    :language: yaml
    :emphasize-lines: 5,10-13
    :linenos:

base: /
errorHandling: {  }
languages:
  -
    title: English
    enabled: true
    languageId: 0
    base: /
    typo3Language: default
    locale: en_US.UTF-8
    iso-639-1: en
    navigationTitle: English
    hreflang: en-us
    direction: ltr
    flag: us
rootPageId: 1
routes: {  }

Literal includes can even be used to render the difference between files, without having to create a diff file first:

Documentation/SiteConfiguration/Index.rst

..  literalinclude:: /_CodeSnippets/LiteralIncludes/example.yaml
    :diff: /_CodeSnippets/LiteralIncludes/example_de.yaml

base: /
errorHandling: {  }
languages:
  -
    title: English
    enabled: true
    languageId: 0
    base: /
    typo3Language: default
    locale: en_US.UTF-8
    iso-639-1: en
    navigationTitle: English
    hreflang: en-us
    direction: ltr
    flag: us
rootPageId: 1
routes: {  }

Placeholders

Placeholders in this context are named tags in code and example URLs where the exact value does not matter, but is referenced in the surrounding documentation. Use the Backus-Naur form <placeholder-name> for placeholders in code and URLs, i.e. use angle brackets to encapsulate the placeholder name.

For example in PHP

Set up a controller class to handle user interaction with the entity data
model:

..  code-block:: php

    class <Entity>Controller extends ActionController
    {
        ..
    }

where `<Entity>` corresponds to the entity data model class name.

or on the command line

Importing a TYPO3 dump file is as simple as running:

..  code-block:: bash

    typo3/sysext/core/bin/typo3 impexp:import <file>

where `<file>` can be the absolute path on the server or the relative path
in the TYPO3 project folder.

or in an example URL

The TYPO3 backend normally appends the session token ID to the URL as
follows: :samp:`https://example.org/typo3/main?token=<token-id>`.

In the XML and HTML markup languages, which make extensive use of angle brackets, the comment tag  is used to insert placeholders. A <placeholder-name> looks like a regular element and would lead to confusion.

Outdated code block formats

For historic reasons the :caption: option is missing in many code blocks. Try to add them whenever you touch the RST files. Do not add new code blocks without a caption stating the file name. It is often very confusing for new developers where a certain code snippet should go. The recommended file name can help to clear this up.

We recommend that you always write the language name after the code block directive. This makes it easier for first time contributors to adjust or copy-paste code blocks. For historic reasons there are code blocks without an explicit language.

If you do not explicitly set the language, the default language (PHP) is used.

In the past a simplified shorthand directive was widely used: A sentence ending with two double colon ::, followed by a new line and an indented block of code. This quick syntax has several drawbacks:

It is confusing to developers who seldom contribute
We cannot give a caption and state the file name where the code should go.
The script language is only stated implicitly.
Such code blocks cannot be easily copy-pasted to use them as a foundation for your own code blocks.

You can change these code blocks like this:

UpdateShorthandCode.diff

 The extension already contains some unit tests that extend `typo3/testing-framework`'s base
-unit test class in directory :file:`Tests/Unit/Hooks` (stripped):

..  code-block:: php
    :caption: <extension_key>/Tests/Unit/Hooks/DataHandlerFlushByTagHookTest.php

      <?php
      namespace Lolli\Enetcache\Tests\Unit\Hooks;