thanks @pjode
I’m using in almost anything that requires external input validation
Phoenix controllers
I use on phoenix controllers to have user input validation and OpenAPI generation, you can find a simple example here
Most applications will be fine with just Ecto changesets, it have great validation capabilities and a lot of types.
Some applications may have APIs that have different shape compared to their data on DB. You can use Ecto virutal fields or different schemas for the API. I find it easier to maintain Zoi schemas compared to maintaining Ecto schemas + changesets.
Parse env vars
Since environment variables can come in different types and shapes, I use Zoi to parse it:
# runtime.exs
config, :my_app,
auth_enabled?: Zoi.string_boolean() |> Zoi.parse!(System.get_env("AUTH_ENABLED"))
And since the example above is a bit verbose I created a small helper in my applications:
config, :my_app,
auth_enabled?: Env.parse!(Zoi.string_boolean(), "AUTH_ENABLED")
This keeps your configuration consistent, so the runtime.exs and config.exs will have same types.
If you don’t parse these vars, the key auth_enabled? will be boolean in config.exs and string in runtime.exs. This can potentially break your application.
NimbleOptions alternative
NimbleOptions is very good to validate keywords and their inner data. Zoi.keyword/2 is an alternative that implements a similar feature set. There is a small example on the docs here, which uses Zoi to validate options, generate it’s typespec and documentation
Integration with external APIs
I mainly work with 3rd party API integrations, specifically in the payments field. The payment’s providers doesn’t have much consistency on how they return the data in their APIs. For every integration, it’s good to parse the data to a format and shape that your internal application understands it.
Also integrating with those APIs, you may find a lot of edge cases such as fields that may have more than one data types. Zoi unions are a great solution for that.
AI
@mikehostetler and the whole Jido ecosystem are using Zoi for multiple purposes:
- Structured outputs - Zoi schemas with OpenAPI generation
- Zoi Struct as replacement for typed_struct
NimbleOptionsalternative
And probably even more.
Last year I created a blog post explaining my motivation on building this lib, you can check it here
