This plugin requires PHP 5.2.3 or later
This plugin is still experimental.

• meta_yaml - DokuWiki official plugin page

This plugin sets and shows DokuWiki meta data. It can also modify the meta headers such as 'description' or 'keywords' of a specific page. This plugin may be attractive for template designers and plugin developers.

There was a similar plugin, 'meta plugin'. But the functionalities were limited and it didn't support array data. Since array data is essential for meta data, this plugin applies a YAML format for a syntax of meta data.

• Set named meta data as a single value or an array by using YAML.
• Execute some command (list, print_r) to show meta data in the page.
• Append to or replace meta-header (description, keywords, robots etc.) by meta data defined the page.

YAML - Official site

• Readable by human being as well as machine easily. (line/white-space delimitters)
• Able to describe a named value, sequential array and key-value data sets.
• Very simple syntax.
• Great codes are available from Symfony framework developed by Fabien Potencier.

What should be concerned about YAML

• YAML class from Symfony framework needs PHP 5.2.3 or later

You can describe any kind of meta data with YAML between <meta_yaml> and </meta_yaml>.

You can display YAML-formatted meta data of the page by using 'list' or 'print_r' command.

<meta_yaml>
# Hashed data (block)
Sites:
  Site1: http://www.google.com/
  Site2: http://www.yahoo.com/

# Hashed data (inline)
Sites: { Site1: http://www.google.com/, Site2: http://www.yahoo.com/ }

# Collection (block)
SiteNames:
  - Google
  - Yahoo

# Collection (inline)
SiteNames: [Google,Yahoo]

# Show those data in the page as print_r format
command:
  - { print_r:Sites }
  - { print_r:SiteNames }
</meta_yaml>

After save the page, you can see meta data that you set above.

-----------------------
Meta YAML plugin output
-----------------------
-------------
print_r Sites
-------------
Array
(
    [Site1] => http://www.google.com/
    [Site2] => http://www.yahoo.com/
)
-----------------
print_r SiteNames
-----------------
Array
(
    [0] => Google
    [1] => Yahoo
)
---------------

list

The 'list' command shows specific/all meta data with YAML format.

<meta_yaml>
command:
  - { list:description }
  - { list:all }
</meta_yaml>

The array of meta data will be shown by YAML format. You can see that YAML format is human-friendly format.

----------------
list description
----------------
tableofcontents:
  - { hid: meta-yaml_plugin, title: 'meta-YAML plugin', type: ul, level: 1 }
  - { hid: introduction, title: Introduction, type: ul, level: 2 }
  - { hid: what_it_can_do, title: 'What it can do', type: ul, level: 1 }
  - { hid: why_yaml, title: 'Why YAML ?', type: ul, level: 2 }
...

print_r

The 'print_r' command is similar to the list command, it shows meta data with print_r format instead.

<meta_yaml>
command:
  - { print_r:description }
  - { print_r:all }
</meta_yaml>

The array of meta data will be shown by print_r format of PHP.

-------------------
print_r description
-------------------
Array
(
    [tableofcontents] => Array
        (
            [0] => Array
                (
                    [hid] => meta-yaml_plugin
                    [title] => meta-YAML plugin
                    [type] => ul
                    [level] => 1
                )

            [1] => Array
                (...

You can replace or append some data to meta-header such as 'description', 'keywords', etc. Set key-value sets in a 'meta-headers' array.

If you use '%abstract%' or '%keywords%', they are replaced by a first section or tags from Tag plugin.

<meta_yaml>
# Abstract for the page
meta-headers:
  description: This is an instruction page for the meta_yaml plugin.
</meta_yaml>

<meta_yaml>
# Using first section as an abstract of the page
meta-headers:
  description: %abstract%

# Tag plugin put the tags in 'keywords' meta-header. You can append some keywords to tags.
meta-headers:
  keywords: %subject%,plugin,instruction
</meta_yaml>

• Inheritable meta data for namespaces
• Some plugins using this plugin
  • Self-declaration of language of page contents/user interface.
  • Template switcher by meta data of a specific namespace or page.
• Some commands
  • Auto-increment command for page-view count
• YAMLize all meta file from core?

Download and extract meta_yaml.zip and place it in lib/plugins/ directory.