Antora C++ Tagfiles Extension

This extension allows you to use tagfiles with C++ symbols in your Antora projects. Tagfiles are usually generated by Doxygen and contain information about the symbols in your C++ codebase.

cpp:std::vector[]

This will render as a link to the std::vector class in the tagfile.

https://en.cppreference.com/w/cpp/container/vector[std::vector,window="_blank"]

Which renders as std::vector.

The extension supports fundamental types, custom tagfiles, using namespaces directives, template parameters, nested symbols, and replacing target names.

Configuration

npm

Install this extension

npm i -D @alandefreitas/antora-cpp-tagfiles-extension

Playbook

Append the following in your antora-playbook.yaml:

antora:
  extensions:
    - require: '@alandefreitas/antora-cpp-tagfiles-extension' # (1)
      cpp-tagfiles:
          files: # (2)
            - file: ./doc/tagfiles/boost-url-doxygen.tag.xml
              base_url: 'xref:reference:'
            - file: ./doc/tagfiles/boost-system-doxygen.tag.xml
              base_url: https://www.boost.org/doc/libs/master/libs/system/doc/html/
            - file: ./doc/tagfiles/boost-core-doxygen.tag.xml
              base_url: https://www.boost.org/doc/libs/master/libs/core/doc/html/
            - file: ./doc/tagfiles/boost-filesystem-doxygen.tag.xml
              base_url: https://www.boost.org/doc/libs/master/libs/filesystem/doc/
          using-namespaces: (3)
            - boost::urls
            - boost::urls::grammar
            - boost::system
            - boost::core

• <1> npm package name: @alandefreitas/antora-cpp-tagfiles-extension (required)

• <2> List of tagfiles to be used by the extension

• <3> List of namespaces to be used by the extension

Components

Components can also set their own tagfiles. Append following in your antora.yaml:

ext:
  cpp-tagfiles: # (1)
      files: # (2)
        - file: ./doc/tagfiles/boost-url-doxygen.tag.xml
          base_url: 'xref:reference:'
        - file: ./doc/tagfiles/boost-system-doxygen.tag.xml
          base_url: https://www.boost.org/doc/libs/master/libs/system/doc/html/
        - file: ./doc/tagfiles/boost-core-doxygen.tag.xml
          base_url: https://www.boost.org/doc/libs/master/libs/core/doc/html/
        - file: ./doc/tagfiles/boost-filesystem-doxygen.tag.xml
          base_url: https://www.boost.org/doc/libs/master/libs/filesystem/doc/
      using-namespaces: (3)
        - boost::urls
        - boost::urls::grammar
        - boost::system
        - boost::core

• <1> The playbook needs to have the extension enabled

• <2> List of tagfiles to be used by the component

• <3> List of namespaces to be used by the component

These tagfiles only affect the component where they are defined.

C++ Reference

The extension include the cppreference tagfile by default. Any unknown symbol in custom tagfiles will be searched in the cppreference tagfile.

Features

Unknown symbols

If the extension can’t find a symbol in the tagfile, it will render the symbol as plain text.

cpp:unknown[]

This will render as plain text:

`unknown`

Which renders as unknown.

Fundamental types

Fundamental types include links to cppreference:

cpp:int[]

This will render as a link to the int fundamental type in cppreference.

`https://en.cppreference.com/w/cpp/language/types#Standard_integer_types[int,window="_blank"]`

Which renders as int.

Symbols from Tagfiles

Symbols from tagfiles are rendered as links:

cpp:std::string[]

This will render as a link to the std::string class in the cppreference tagfile.

`https://en.cppreference.com/w/cpp/string/basic_string[std::string,window="_blank"]`

Which renders as std::string.

Template classes without parameters are also supported:

cpp:std::vector[]

This will render as a link to the std::vector class in the cppreference tagfile.

`https://en.cppreference.com/w/cpp/container/vector[std::vector,window="_blank"]`

Which renders as std::vector.

Symbols from custom tagfiles are rendered without the window="_blank" attribute if the base_url relative.

cpp:is_charset[]

This will render as a link to the boost::urls::grammar::is_charset class in the boost-url-doxygen.tag.xml tagfile.

`xref:reference:boost/urls/grammar/is_charset.adoc[boost::urls::grammar::is_charset]`

Components

When components define their own tagfiles, these tagfiles only affect the component where they are defined and they have precedence over tagfiles defined in the playbook.

cpp:boost::urls::string_token::assign_to[]

This will render as a link to the boost::urls::string_token::assign_to class in the boost-url-doxygen.tag.xml tagfile.

`xref:reference:boost/urls/string_token/assign_to.adoc[boost::urls::string_token::assign_to]`

However, if the some other component uses cpp: for the same symbol without the appropriate tagfile, the symbol will be rendered as plain text.

`boost::urls::string_token::assign_to`

Namespaces

Default namespaces can also be defined in the playbook or in the component. When there’s no match for the full symbol, the extension will try to find the symbol in the namespaces. Assuming boost::urls::grammar is defined in the playbook or the component:

cpp:boost::urls::grammar::is_charset[]
cpp:is_charset[]

This will render as a link to the boost::urls::grammar::is_charset class in the boost-url-doxygen.tag.xml tagfile. However, the link text will be whatever was provided to the extension.

`xref:reference:boost/urls/grammar/is_charset.adoc[boost::urls::grammar::is_charset]`
`xref:reference:boost/urls/grammar/is_charset.adoc[is_charset]`

As with tagfiles, the namespaces defined in a component only affect that component. The namespace std:: can also be defined:

cpp:std::string[]
cpp:string[]

This will render as a link to the std::string class in the cppreference tagfile.

`https://en.cppreference.com/w/cpp/string/basic_string[std::string,window="_blank"]`
`https://en.cppreference.com/w/cpp/string/basic_string[string,window="_blank"]`

Template parameters

Template parameters are supported. The extension will also include links from the tagfile for the template parameters.

cpp:std::vector<int>[]

This will render as a link to the std::vector<int> class in the cppreference tagfile.

`https://en.cppreference.com/w/cpp/container/vector[std::vector,window="_blank"]<https://en.cppreference.com/w/cpp/language/types#Standard_integer_types[int,window=_blank]>`

Which renders as std::vector<int>.

Symbols from custom tagfiles can also be used with template parameters:

cpp:std::vector<url_view>[]

This will render as a link to the std::vector<url_view> class in the cppreference tagfile.

`https://en.cppreference.com/w/cpp/container/vector[std::vector,window=\"_blank\"]<url_view>`

Which renders as std::vector<url_view>.

If the namespace boost::urls is being used in the context, it will also be used to resolve url_view:

cpp:std::vector<url_view>[]

This will render as a link to the std::vector<url_view> class in the cppreference tagfile.

`https://en.cppreference.com/w/cpp/container/vector[std::vector,window=\"_blank\"]<xref:reference:boost/urls/url_view.adoc[url_view]>`

Nested symbols

The extension supports nested symbols:

cpp:boost::urls::url_view_base::segments[]

This will render as a link to the boost::urls::url_view_base::segments class in the boost-url-doxygen.tag.xml tagfile.

`xref:reference:boost/urls/url_view_base/segments.adoc[boost::urls::url_view_base::segments]`

Which is the page for the boost::urls::url_view_base::segments symbol defined in the tagfile rather than only boost::urls::url_view_base.

Sometimes there’s no page for the nested symbol in the tagfile, so the link will redirect to the page for the parent symbol.

cpp:std::vector::iterator[]

This will render as a link to the std::vector class in the cppreference tagfile:

`https://en.cppreference.com/w/cpp/container/vector[std::vector::iterator,window=\"_blank\"]`

Which renders as std::vector::iterator.

Note that there’s no page for std::vector::iterator in cppreference, so the link will redirect to the page for the parent std::vector symbol.

Templates and nested symbols can also be combined:

cpp:std::vector<url_view_base::segments>::iterator[]

This will render as a link to the std::vector<url_view_base::segments>::iterator class in the cppreference tagfile.

`https://en.cppreference.com/w/cpp/container/vector[std::vector,window="_blank"]<xref:reference:boost/urls/url_view_base/segments.adoc[url_view_base::segments]>::https://en.cppreference.com/w/cpp/container/vector[std::vector::iterator,window="_blank"]
`

Replacing target names

The extension can replace the target names of the links.

cpp:std::vector[sequential container]

This will render as a link to the std::vector class in the cppreference tagfile with the text "sequential container".

`https://en.cppreference.com/w/cpp/container/vector[sequential container,window="_blank"]`

Which renders as sequential container.

When providing custom text for a template class, the extension will only link the main symbol:

cpp:std::vector<int>[sequential container]

This will render as a link to the std::vector class in the cppreference tagfile with the text "sequential container".

`https://en.cppreference.com/w/cpp/container/vector[sequential container,window="_blank"]`

Which also renders as sequential container.

cpp:url_view_base::segments[URL segments]

This will render as a link to the boost::urls::url_view_base::segments class in the boost-url-doxygen.tag.xml tagfile with the text "URL segments".

`xref:reference:boost/urls/url_view_base/segments.adoc[URL segments]`