- Qt 6.8
- QDoc Manual
- Supporting Derived Projects
- Qt 6.8.0 Reference Documentation

Format-specific Configuration Variables ◦ Example Manifest Files

# Supporting Derived Projects

Some configuration variables allow you to use QDoc to support Qt-based projects. They allow your project to contain links to the online Qt documentation, which means that QDoc will be able to create links to the class reference documentation, without any explicit linking command.

## description

The description variable holds a short description of the associated project.

See also project.

## indexes

The `indexes` variable defines a set of paths to index files to load.

     indexes = \
         $QT_INSTALL_DOCS/qtcore/qtcore.index \
         $SOME_OTHER_PROJECT/doc/foo.index

The `indexes` variable provides an alternative to depends for defining project's dependencies. As direct paths are provided, no `-indexdir` command line option(s) are required when invoking QDoc.

It is possible to define dependencies using either variable. Qt documentation only uses the `depends` variable.

See also depends, project and url.

## project

The `project` variable provides a name for the project associated with the `.qdocconf` file. This is a mandatory variable that all projects must set.

The project's name is used to form a file name for the associated project's index file.

     project = QtCreator

This will cause an index file called `qtcreator.index` to be created.

If the project name contains whitespace or special characters, these are replaced with dashes ('-') in the generated index file name.

See also depends, indexes, and description.

## url

The `url` variable holds the base URL for the documentation associated with the current project.

The URL is stored in the generated index file for the project. When we use the index on its own, QDoc will use this as the base URL when constructing links to classes, functions, and other things listed in the index.

     project     = QtCore
     description = Qt Core Reference Documentation
     url         = https://doc.qt.io/qt/

     ...

This ensures that whenever QDoc generates references to entities in the Qt Core module, the base URL is `https://doc.qt.io/qt/`.

See also depends, indexes and url.examples.

## url.examples

The `url.examples` variable holds the base URL for the examples associated with the current project.

If defined, a link to the example project directory is generated at the end of each example documentation page. The `url.examples` variable refers to the root directory of the examples related to this project; it can be a link to an online repository (starting with http:// or https://), or to the local file system (`file://`).

If `url.examples` is not defined, QDoc will output a list of example's files and images instead.

For example, given these definitions:

     url.examples = "https://code.qt.io/cgit/qt/qtbase.git/tree/examples/"
     examplesinstallpath = corelib

Then, for the following \example command:

     /*!
         \example threads/semaphores
         ...
     */

QDoc generates a link to `https://code.qt.io/cgit/qt/qtbase.git/tree/examples/corelib/threads/semaphores`.

If the URL contains more components (for example, a query string) after the example path, \1 can be used as a placeholder for the path:

     url.examples = "https://code.qt.io/cgit/qt/qtbase.git/tree/examples/\1?h=$QT_VER"
     examplesinstallpath = corelib

Given the same \example command as above and assuming that `$QT_VER` expands to `5.13`, the generated URL is `https://code.qt.io/cgit/qt/qtbase.git/tree/examples/corelib/threads/semaphores?h=5.13`.

`url.examples` variable was introduced in QDoc version 5.13.

See also url, examplesinstallpath, and \example.

## How to Support Derived Projects

This feature makes use of the comprehensive indexes generated by QDoc when it creates the Qt reference documentation.

For example, qtgui.qdocconf (the configuration file for Qt GUI) contains the following variable definitions:

     project     = QtGui
     description = Qt GUI Reference Documentation
     url         = http://doc.qt.io/qt/

     ...

The project variable name is used to form a file name for the index file; in this case the `qtgui.index` file is created. The url is stored in the index file. Afterwards, QDoc will use this as the base URL when constructing links to classes, functions, and other things listed in the index.

See also depends, indexes, project, and url.