# YAML format

YAML (a recursive acronym for "YAML Ain't Markup Language") is a human-readable data-serialization language. It is commonly used for configuration files and in applications where data is being stored or transmitted. YAML targets many of the same communications applications as Extensible Markup Language (XML) but has a minimal syntax which intentionally differs from SGML. It uses both Python-style indentation to indicate nesting, and a more compact format that uses [] for lists and {} for maps making YAML 1.2 a superset of JSON.

# Dependencies

DataTree API supports 2 YAML reader/writer implementations. For example, to use SnakeYAML's version, just add SnakeYAML JARs to the classpath. If DataTree detects SnakeYAML API on classpath, DataTree will use SnakeYAML API to read/write YAML documents.

<!-- DATATREE API -->
<dependency>
    <groupId>com.github.berkesa</groupId>
    <artifactId>datatree-adapters</artifactId>
    <version>1.0.15</version>
</dependency>

<!-- SNAKEYAML API -->
<dependency>
    <groupId>org.yaml</groupId>
    <artifactId>snakeyaml</artifactId>
    <version>1.28</version>
</dependency>

# Reading and writing YAML documents

// Parsing YAML document
String yaml = " ... YAML document ... ";
Tree document = new Tree(yaml, "yaml");

// Getting / setting values
for (Tree child: document.get("listOfItems")) {
  ...
}
document.clear("listOfItems");

// Generating YAML string from Tree
String yaml = document.toString("yaml");

If there is more than one YAML implementation on classpath, the preferred implementation is adjustable with the following System Properties:

// Using SnakeYAML API:
-Ddatatree.yaml.reader=io.datatree.dom.adapters.YamlSnakeYaml
-Ddatatree.yaml.writer=io.datatree.dom.adapters.YamlSnakeYaml

// Using Jackson YAML API:
-Ddatatree.yaml.reader=io.datatree.dom.adapters.YamlJackson
-Ddatatree.yaml.writer=io.datatree.dom.adapters.YamlJackson

# Required dependencies of YAML adapters