laika.config

A value containing an AST element obtained from text markup or templates.

Such a value can be used in scenarios where substitution variables in templates or markup want to refer to other AST elements and include them into their AST tree as is.

API for retrieving configuration values based on a string key and a decoder.

Config instances are used in many places in this library, each Document, DocumentTree and Directive has a Config instance associated with it.

One use case for configuration is controlling the behaviour of built-in features, like setting the navigation order or the depth for table of contents.

A second use case is user configuration, where custom variables can be set in configuration files or headers and then referenced in templates or markup with the syntax ${ref.path}.

The key is a path separated by '.', which allows to reference nested objects in the configuration.

Built-in decoders are available for simple types like String, Int, Double, Boolean and any Seq consisting of those values.

It also comes with a decoder for Path, which resolves relative paths in the configuration against the (virtual) path of the origin.

This API is usually used with values obtained by parsing HOCON, as specified in https://github.com/lightbend/config/blob/master/HOCON.md, but the API is generic and can also be used with values specified programmatically.

Please note that Laika does not depend on the Typesafe Config library or any of its commonly used Scala wrappers or forks. It has its own HOCON parser, which implements the full spec while still being minimal and lightweight. It also ensures the FP properties are kept intact, e.g. it has full referential transparency and does not throw Exceptions like most of the alternatives.

A builder for creating a Config instance programmatically.

While it's most common in Laika that Config instances are obtained by parsing HOCON, instances can also be created entirely programmatically, or by a combination of HOCON and programmatic values if an existing fallback is used with builder.

Companion factory for ConfigBuilder instances.

A type class that can decode a ConfigValue to an instance of T.

Companion containing default decoder implementations for simple values and Seq's.

A type class that can encode a value of type T as a ConfigValue.

Companion containing default encoder implementations for simple values and Seq's.

Base trait for all configuration errors that occurred during parsing, resolving, retrieving or convering configuration values.

Multiple errors that occurred when processing configuration.

A ConfigError as a RuntimeException for use cases where a Throwable is required.

A parser for obtaining a Config instance from a HOCON string.

The HOCON format expected by this parsers is specified at https://github.com/lightbend/config/blob/master/HOCON.md

An error that occurred when parsing HOCON input.

Multiple errors that occurred when parsing HOCON input.

An error that occurred when resolving the interim result of a parsing operation.

An error that occurred when loading a resource, before parsing could start.

The base trait for all configuration values.

This data structure is quite similar to those found in common JSON libraries (HOCON is a JSON superset after all).

The only exception is one special type: the ASTValue which can hold an instance of a document AST obtained from parsing text markup.

This can be useful in scenarios where substitution variables in templates or markup want to refer to other AST elements and include them into their AST tree as is.

An error that occurred when decoding a configuration value to a target type.

A defaultKey can be used for commonly used configuration objects like AutonumberConfig that are expected to be mapped to a specific key, like autonumbering without requiring the user to remember these keys.

val config: Config = ???
val res: ConfigResult[AutonumberConfig] = config.get[AutonumberConfig]

In the example above retrieval happens solely based on the type of the result with the associated key being specified by an implicit DefaultKey.

Multiple errors that occurred when processing configuration for a document.

An empty configuration instance.

A single field of an object value.

Indicates that a value found in the configuration does not have the expected type so that type conversion is not even attempted.

Constants for configuration keys for the library's core configuration entries.

A required value that could not be found.

The default implementation of the Config API.

The origin of a configuration value.

Origins can be used to distinguish values from a specific Config instance from those which were inherited from a fallback, which might be relevant in scenarios where relative paths need to be resolved.

Base trait for all simple configuration values.

A value tagged with its origin.

Multiple errors that occurred when processing configuration for a document tree.

A generic error for invalid values.