|
|
# YAML Tutorial
|
|
|
|
|
|
All of Plex Meta Manager's Config, Metadata, Overlay, and Playlist Files are written in the YAML data structure.
|
|
|
|
|
|
This tutorial will help you understand the specific parts of the files.
|
|
|
|
|
|
## Example YAML File
|
|
|
|
|
|
```yaml
|
|
|
libraries:
|
|
|
Movies:
|
|
|
metadata_path:
|
|
|
- pmm: basic
|
|
|
- pmm: imdb
|
|
|
overlay_path:
|
|
|
- pmm: ribbon
|
|
|
template_variables:
|
|
|
use_metacritic: false
|
|
|
use_common: false
|
|
|
TV Shows:
|
|
|
metadata_path:
|
|
|
- pmm: basic
|
|
|
- pmm: imdb
|
|
|
overlay_path:
|
|
|
- pmm: ribbon
|
|
|
settings:
|
|
|
cache: true
|
|
|
cache_expiration: 60
|
|
|
asset_directory:
|
|
|
- config/movie assets
|
|
|
- config/tv assets
|
|
|
```
|
|
|
|
|
|
## Basic YAML Syntax
|
|
|
|
|
|
A YAML format primarily uses 3 node types:
|
|
|
|
|
|
1. Dictionaries/Mappings:
|
|
|
The content of a mapping node is an unordered set of key/value node pairs, with the restriction that each of the keys is unique. YAML places no further restrictions on the nodes.
|
|
|
|
|
|
2. Lists/Arrays:
|
|
|
The content of a list node is an ordered series of zero or more nodes. In particular, a sequence may contain the same node more than once. It could even contain itself.
|
|
|
|
|
|
3. Literals (Strings, numbers, boolean, etc.):
|
|
|
The content of a scalar node is an opaque datum that can be presented as a series of zero or more Unicode characters.
|
|
|
|
|
|
Let us try and identify where these appear in the sample YAML file we saw earlier.
|
|
|
|
|
|
```yaml
|
|
|
# Strats with a top level Dictionary with keys `libraries` and `settings`
|
|
|
libraries: # Value is a Dictionary with keys `Movies` and `TV Shows`
|
|
|
Movies: # Value is a Dictionary with keys `metadata_path` and `overlay_path`
|
|
|
metadata_path: # Value is a List with two Items
|
|
|
- pmm: basic # List Item is a Dictionary with one key pair whose value is a String Literal
|
|
|
- pmm: imdb # List Item is a Dictionary with one key pair whose value is a String Literal
|
|
|
overlay_path: # Value is a List with one Item
|
|
|
- pmm: ribbon # List Item is a Dictionary with keys `pmm` and `template_variables` with `pmm`'s value a String Literal
|
|
|
template_variables: # Value is a Dictionary with keys `use_metacritic` and `use_common`
|
|
|
use_metacritic: false # Value is a Boolean Literal
|
|
|
use_common: false # Value is a Boolean Literal
|
|
|
TV Shows: # Value is a Dictionary with keys `metadata_path` and `overlay_path`
|
|
|
metadata_path: # Value is a List with two Items
|
|
|
- pmm: basic # List Item is a Dictionary with one key pair whose value is a String Literal
|
|
|
- pmm: imdb # List Item is a Dictionary with one key pair whose value is a String Literal
|
|
|
overlay_path: # Value is a List with one Item
|
|
|
- pmm: ribbon # List Item is a Dictionary with one key pair whose value is a String Literal
|
|
|
settings: # Value is a Dictionary with keys `cache` and `cache_expiration`
|
|
|
cache: true # Value is a Boolean Literal
|
|
|
cache_expiration: 60 # Value is a Number Literal
|
|
|
asset_directory: # Value is a List with two Items
|
|
|
- config/movie assets # List Item is a String Literal
|
|
|
- config/tv assets # List Item is a String Literal
|
|
|
```
|
|
|
|
|
|
## Indentation
|
|
|
|
|
|
A YAML file relies on whitespace and indentation to indicate nesting. The number of spaces used for indentation doesn’t matter as long as they are consistent.
|
|
|
|
|
|
**It is critical to note that tab characters cannot be used for indentation in YAML files; only spaces can be used.**
|
|
|
|
|
|
```yaml
|
|
|
libraries: # Nesting Level 1
|
|
|
Movies: # Nesting Level 2
|
|
|
metadata_path: # Nesting Level 3
|
|
|
- pmm: basic # Nesting Level 4
|
|
|
- pmm: imdb # Nesting Level 4
|
|
|
overlay_path: # Nesting Level 3
|
|
|
- pmm: ribbon # Nesting Level 4
|
|
|
template_variables: # Nesting Level 5
|
|
|
use_metacritic: false # Nesting Level 6
|
|
|
use_common: false # Nesting Level 6
|
|
|
TV Shows: # Nesting Level 2
|
|
|
metadata_path: # Nesting Level 3
|
|
|
- pmm: basic # Nesting Level 4
|
|
|
- pmm: imdb # Nesting Level 4
|
|
|
overlay_path: # Nesting Level 3
|
|
|
- pmm: ribbon # Nesting Level 4
|
|
|
settings: # Nesting Level 1
|
|
|
cache: true # Nesting Level 2
|
|
|
cache_expiration: 60 # Nesting Level 2
|
|
|
```
|
|
|
|
|
|
## Dictionaries
|
|
|
|
|
|
Dictionaries are used to associate key/value pairs that are unordered. Dictionaries can be nested by increasing the indentation, or new dictionaries can be created at the same level by resolving the previous one.
|
|
|
|
|
|
```yaml
|
|
|
cache: true
|
|
|
cache_expiration: 60
|
|
|
```
|
|
|
|
|
|
The "keys" are `cache` and `cache_expiration` and the "values" are `true` and `60` respectively.
|
|
|
|
|
|
### In-Line Dictionaries
|
|
|
|
|
|
you can represent a dictionary on a single line by using `{` and `}`
|
|
|
|
|
|
```yaml
|
|
|
settings: {cache: true, cache_expiration: 60}
|
|
|
```
|
|
|
|
|
|
is equivalent to
|
|
|
|
|
|
```yaml
|
|
|
settings:
|
|
|
cache: true
|
|
|
cache_expiration: 60
|
|
|
```
|
|
|
|
|
|
## Lists
|
|
|
|
|
|
Lists in YAML are represented by using the hyphen (-) and space. They are ordered and can be embedded inside a map using indentation.
|
|
|
|
|
|
```yaml
|
|
|
asset_directory:
|
|
|
- config/movie assets
|
|
|
- config/tv assets
|
|
|
```
|
|
|
|
|
|
The first item in the list is `config/movie assets` and the second is `config/tv assets`.
|
|
|
|
|
|
### In-Line Lists
|
|
|
|
|
|
you can represent a dictionary on a single line by using `[` and `]`
|
|
|
|
|
|
```yaml
|
|
|
settings:
|
|
|
asset_directory: [config/movie assets, config/tv assets]
|
|
|
```
|
|
|
|
|
|
is equivalent to
|
|
|
|
|
|
```yaml
|
|
|
settings:
|
|
|
asset_directory:
|
|
|
- config/movie assets
|
|
|
- config/tv assets
|
|
|
```
|
|
|
|
|
|
## Literals
|
|
|
|
|
|
Literals can come in multiple types:
|
|
|
|
|
|
* String: any sequence of characters
|
|
|
|
|
|
* Number: any representation of a number
|
|
|
|
|
|
* Boolean: `true` or `false`
|
|
|
|
|
|
### String Literals
|
|
|
|
|
|
The string literals do not require to be quoted. It is only important to quote them when they contain a value that can be mistaken as a special character.
|
|
|
|
|
|
Here is an example where the string has to be quoted as `&` and `:` are special characters.
|
|
|
|
|
|
YAML Special Characters: `{`, `}`, `[`, `]`, `,`, `&`, `:`, `*`, `#`, `?`, `|`. `-`, `<`. `>`, `=`, `!`, `%`, `@`, `\`
|
|
|
|
|
|
There are many occurrences of these special characters where quotes are not needed but if the YAML fails to load it could easily be because one of these are unquoted.
|
|
|
|
|
|
```yaml
|
|
|
message1: YAML & JSON # breaks as a & is a special character
|
|
|
message2: "YAML & JSON" # Works as the string is quoted
|
|
|
message: 3: YAML # breaks as a : is a special character
|
|
|
"message: 3": YAML # Works as the key string is quoted
|
|
|
```
|
|
|
|
|
|
#### Multiline Strings
|
|
|
|
|
|
Strings can be interpreted as multiline using the pipe (`|`) character.
|
|
|
|
|
|
```yaml
|
|
|
message: |
|
|
|
this is
|
|
|
a real multiline
|
|
|
message
|
|
|
```
|
|
|
|
|
|
This would be read as `this is\na real multiline\nmessage`
|
|
|
|
|
|
## Comments
|
|
|
|
|
|
YAML file also supports comments, unlike JSON. A comment starts with #.
|
|
|
|
|
|
```yaml
|
|
|
# Strats with a top level Dictionary with keys `libraries` and `settings`
|
|
|
libraries: # Value is a Dictionary with keys `Movies` and `TV Shows`
|
|
|
```
|
|
|
|
|
|
Everything after `#` on a line is ignored.
|
|
|
|
|
|
## Anchors and Aliases
|
|
|
|
|
|
With a lot of configuration, configuration files can become quite large.
|
|
|
|
|
|
In YAML files, anchors (`&`) and aliases (`*`) are used to avoid duplication. When writing large configurations in YAML, it is common for a specific configuration to be repeated. For example, the vars config is repeated for all three services in the following YAML snippet.
|
|
|
|
|
|
```yaml
|
|
|
libraries:
|
|
|
Movies:
|
|
|
metadata_path:
|
|
|
- pmm: basic
|
|
|
- pmm: imdb
|
|
|
overlay_path:
|
|
|
- pmm: ribbon
|
|
|
template_variables:
|
|
|
use_metacritic: false
|
|
|
use_common: false
|
|
|
TV Shows:
|
|
|
metadata_path:
|
|
|
- pmm: basic
|
|
|
- pmm: imdb
|
|
|
overlay_path:
|
|
|
- pmm: ribbon
|
|
|
```
|
|
|
|
|
|
As more and more things are repeated for large configuration files, this becomes tedious.
|
|
|
|
|
|
Anchors and aliases allow us to rewrite the same snippet without having to repeat any configuration.
|
|
|
|
|
|
Anchors (`&`) are used to define a chunk of configuration, and aliases (`*`) are used to refer to that chunk at a different part of the configuration.
|
|
|
|
|
|
```yaml
|
|
|
libraries:
|
|
|
Movies:
|
|
|
metadata_path: &paths # Anchor called `paths`
|
|
|
- pmm: basic
|
|
|
- pmm: imdb
|
|
|
overlay_path:
|
|
|
- pmm: ribbon
|
|
|
template_variables:
|
|
|
use_metacritic: false
|
|
|
use_common: false
|
|
|
TV Shows:
|
|
|
metadata_path: *paths # Alias to call the above `paths` section
|
|
|
overlay_path:
|
|
|
- pmm: ribbon
|
|
|
``` |
