Bindings ​
A Vala binding maps Vala syntax to the C code used in a library. It is often a single Vala API file (.vapi), but can also include a dependencies file (.deps).
Sources Of Bindings ​
Upstream Projects ​
The first source of bindings is from upstream projects. If a project uses GLib with GObjects then a Vala binding can be generated automatically as part of the build process.
The resulting VAPI file can be distributed with the project and ensures it is the most compatible with the project.
For projects not using GObjects a manually written VAPI can be distributed. See Why Distribute Bindings Upstream for details on using either process in an upstream project.
Distributed with Vala ​
The Vala project also includes a large number of bindings for projects that do not distribute the VAPI files.
You can check them out in the vapi directory in the Vala compiler's repository: https://gitlab.gnome.org/GNOME/vala/-/tree/main/vapi
Other notable sources ​
- vala-girs — GIR packages and related bindings metadata
- vala-extra-vapis — Additional VAPI files maintained with by the GNOME Vala project that aren't distributed with Vala
Writing your own VAPI files ​
You can also write your own .vapi files or use a custom .vapi file that someone else has written.
Check out the contents of the guide to learn how.
How to use VAPI files that aren't distributed with packages ​
When .vapi aren't distributed with a package you want to use, you can download or write your own .vapi file and compile your program with it by using the --vapidir option in valac.
For example:
valac --vapidir /path/to/vapi --pkg pkg_name main.valaTypically you would set --vapidir to local directory called vapi in your project. For example:
valac --vapidir ./vapi --pkg pkg_name main.valaDocumentation of Bindings ​
Documentation of bindings may be included in https://valadoc.org
For more info on how to generate your own documentation, check out the Valadoc Guide.