Ruby 1. Parsing a document
1.1. Providing the source
1.2. Localized errors
1.3. Error formats
1.4. Cursor lookup
2. Querying content
2.1. Field values
2.2. List values
2.3. Keys and Comments
2.4. Predefined Types
2.5. Custom Types
3. Querying elements
3.1. Optional/required
3.2. Dynamic layouts
3.3. Requiring all elements
4. Touching elements
4.1. Assert all touched
4.2. Manual touching
5. Error Metadata
5.1. Message
5.2. Text
5.3. Snippet
5.4. Cursor
5.5. Selection
6. Addendum
6.1. A complete example
6.2. AST inspection
6.3. FAQ

Field values

When you query a value you always specify whether that value is optional or required:

document.field('default_settings').required_string_value
document.field('extra_settings').optional_string_value

The optional_* query returns a value or nil, while the required_* query raises a validation error if the value is missing, such as:

The field 'default_settings' must contain a value.

   Line | Content
 >    1 | default_settings:

Fieldset entry values

This works just like on a field:

document.fieldset('image').entry('src').required_string_value
document.fieldset('image').entry('title').optional_string_value

Next page: List values