Attention

TYPO3 v9 has reached its end-of-life September 30th, 2021 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.

You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.

YAML syntax

Following is an introduction to the YAML syntax. If you are familiar with YAML, skip to the TYPO3 specific information:

• YamlFileLoader

See also

A good general introduction to YAML syntax, basic data types, etc.:

• "YAML Syntax" in Grav documentation

The TYPO3 coding guidelines for YAML define some basic rules to be used in the TYPO3 core and extensions. Additionally, yaml has general syntax rules.

• File ending .yaml

• Indenting with 2 spaces (not tabs). Spaces MUST be used. You MUST use the correct indenting level.

• Use UTF-8

• All text is case-sensitive

• Enclose strings with single quotes ('')

Important

The following MUST be adhered to in order to produce valid syntax:

1. Use spaces, not tabs to indent

2. Identing is not optional. It is used to define the hierarchy of the data

To get a better understanding of YAML, you might want to compare YAML with PHP arrays:

PHP:

$a = [
    'key1' => 'value',
    'key2' => [
        'key2_1' => 'value'
];

$b = [
    'apples',
    'oranges',
    'bananas'
];

YAML:

# mapping (key / value pairs)
a:
  key1: 'value'
  key2:
    key2_1: 'value'

# sequence (list)
b:
  - 'apples'
  - 'oranges'
  - 'bananas'