= API Options

[cols="~,~,15%,15%"]
|===
|Name |Description |Default value |Allowed values

|`:attributes`
|Sets document attributes, which override equivalently-named attributes defined in the document unless soft set.
No substitutions are applied to the value of these attributes.
In the hash format, a `nil` value hard unsets the attribute and a `false` value soft unsets the attribute.
|_not set_
a|xref:asciidoc:attributes:document-attributes.adoc[Document attributes] in the following formats:

*Hash* +
`{ 'name' \=> 'value' }`

*Array* +
`[ 'name=value' ]`

*String* (space separated) +
`'name=value'`

|`:backend`
|Selects converter to use.
|`html5`
|`html5`, `docbook5`, `manpage`, or a backend mapped to an available converter

|`:base_dir`
|Sets the base (aka working) directory containing the document and resources.
|Directory of the source file, or the working directory if the source is read from a stream.
|file path

|`:catalog_assets`
|If `true`, the parser captures images and links in the reference table.
(Normally only IDs, footnotes and indexterms are included).
The reference table is available via the `references` property on the `document` AST object.
//NOTE: This is still a primitive and experimental feature.
//It is intended for early adopters to address special use cases.
_(Experimental)._
|`false`
|_Boolean_

|`:converter`
|Specifies a user-supplied converter class or instance, used in place of the converter that is automatically resolved from the `backend` value.
|_not set_
|`Asciidoctor::Converter` class or instance

|`:doctype`
|Sets the document type.
|`article`
|`article`, `book`, `manpage`, `inline`

|`:eruby`
|Specifies the eRuby implementation to use for executing the converter templates written in ERB.
|`erb`
|`erb`, `erubis`

|`:extensions`
|A Ruby block that registers (and possibly defines) xref:extensions:register.adoc[Asciidoctor extensions] for this instance of the processor.
|_not set_
|A Ruby block that conforms to the Asciidoctor extensions API (the same code that would be passed to the `Extensions.register` method).

|`:extension_registry`
|Overrides the extensions registry instance.
Instead of providing a Ruby block containing extensions to register, this option lets you replace the extension registry itself, giving you complete control over how extensions are registered for this processor.
|_not set_
|`Extensions::Registry` instance

|`:logger`
|Shorthand to assign a new value to the global `LoggerManager.logger`.
This is persistent change, so you either have to reset the value afterwards or pass the option each time you call the API.
If value is falsy, it assigns a null logger, effectively turning off logging.
|_not set_
|`Logger` instance

|`:parse_header_only`
|If `true`, the parser stops after reading the header.
|`false`
|_Boolean_

|`:standalone`
|If `true`, generates a standalone output document (which includes the shell around the body content, such as the header and footer).
When converting to a file, the default value is `true`.
Otherwise, the default value is `false`.
The deprecated alias for this option is `:header_footer`.
The default value for this option is opposite of the default value for the CLI.
|_Varies_
|_Boolean_

|`:mkdirs`
|If `true`, the processor creates the necessary output directories if they don't yet exist.
|`false`
|_Boolean_

|`:parse`
|If `true`, the source is parsed eagerly (i.e., as soon as the source is passed to the `load` or `load_file` API).
If `false`, parsing is deferred until the `parse` method is explicitly invoked.
|`true`
|_Boolean_

|`:safe`
|Sets the xref:ROOT:safe-modes.adoc[safe mode].
|`:secure`
|`:unsafe`, `:safe`, `:server`, `:secure`

|`:sourcemap`
|Tracks the file and line number for each parsed block.
Useful for tooling applications where the association between the converted output and the source file is important.
|`false`
|_Boolean_

|`:template_cache`
|Enables the built-in cache used by the template converter when reading the source of template files.
Only relevant if `:template_dirs` is specified.
|`true`
|_Boolean_

//|`:template_dir`
//|Specifies a directory of Tilt-compatible templates to be used instead of the default built-in templates.
//*Deprecated. Use `:template_dirs` instead.*
//|_not set_
//|file path

|`:template_dirs`
|Array of directories containing Tilt-compatible converter templates to be used instead of the default built-in templates.
|_not set_
|Array of file paths

|`:template_engine`
|Template engine to use for the custom converter templates.
The gem with the same name as the engine will be loaded automatically.
This name is also used to build the full path to the custom converter templates.
|_auto_ +
(Set based on the file extension of the custom converter templates found).
|Template engine name (e.g., `slim`, `haml`, `erb`, etc.)

|`:template_engine_options`
|Low-level options passed directly to the template engine.
//(You can see an example in the Bespoke.js converter at https://github.com/asciidoctor/asciidoctor-bespoke/blob/v1.0.0.alpha.1/lib/asciidoctor-bespoke/converter.rb#L24-L28).
|_not set_
|Nested Hash of options with the template engine name as the top-level key and the option name as the second-level key.

|`:timings`
|Capture time taken to read, parse, and convert document.
*Internal use only.*
|_not set_
|`Asciidoctor::Timings` instance

|`:to_file`
|Name of the output file to write, or `true` to use the default output file (`docname` + `outfilesuffix`).
|_not set_
|`true`, file path

|`:to_dir`
|Destination directory for output file(s), relative to `base_dir`.
|Directory containing source file, or working directory if source is read from a stream.
|File path
|===
