Description

Add dedicated subcommand for validation. The process will run pre-processing to discover error or warnings. Instead of producing output, it would only log issues and return with non-zero exit code.

There will be a new extension point that plug-ins can use to run custom Ant targets for additional validation. If there are multiple plugins that use the extension point, then multiple validation steps are run in some order. Each should just log warnings and errors, not product any output.

The validation subcommand could also produce a list of all error and warnings in some format. However, you can output the normal log into an XML file or using a custom build listener you can generate any output you want.

Example uses

$ dita validate -i userguide.ditamap
$ dita validate -i userguide.ditamap --processing-mode=strict

Open items

• Should the default processing mode be strict or lax? For conversion the default is lax.