Files
nushell/crates/nu-plugin/src/lib.rs
Eric Hodel 7071617f18 Allow plugins to receive configuration from the nushell configuration (#10955)
# Description

When nushell calls a plugin it now sends a configuration `Value` from
the nushell config under `$env.config.plugins.PLUGIN_SHORT_NAME`. This
allows plugin authors to read configuration provided by plugin users.

The `PLUGIN_SHORT_NAME` must match the registered filename after
`nu_plugin_`. If you register `target/debug/nu_plugin_config` the
`PLUGIN_NAME` will be `config` and the nushell config will loook like:

        $env.config = {
          # ...
          plugins: {
            config: [
              some
              values
            ]
          }
        }

Configuration may also use a closure which allows passing values from
`$env` to a plugin:

        $env.config = {
          # ...
          plugins: {
            config: {||
              $env.some_value
            }
          }
        }

This is a breaking change for the plugin API as the `Plugin::run()`
function now accepts a new configuration argument which is an
`&Option<Value>`. If no configuration was supplied the value is `None`.

Plugins compiled after this change should work with older nushell, and
will behave as if the configuration was not set.

Initially discussed in #10867

# User-Facing Changes

* Plugins can read configuration data stored in `$env.config.plugins`
* The plugin `CallInfo` now includes a `config` entry, existing plugins
will require updates

# Tests + Formatting

- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting

- [ ] Update [Creating a plugin (in
Rust)](https://www.nushell.sh/contributor-book/plugins.html#creating-a-plugin-in-rust)
[source](https://github.com/nushell/nushell.github.io/blob/main/contributor-book/plugins.md)
- [ ] Add "Configuration" section to [Plugins
documentation](https://www.nushell.sh/contributor-book/plugins.html)
2024-01-15 16:59:47 +08:00

54 lines
1.9 KiB
Rust

#![allow(clippy::needless_doctest_main)]
//! # Nu Plugin: Plugin library for Nushell
//!
//! This crate contains the interface necessary to build Nushell plugins in Rust.
//! Additionally, it contains public, but undocumented, items used by Nushell itself
//! to interface with Nushell plugins. This documentation focuses on the interface
//! needed to write an independent plugin.
//!
//! Nushell plugins are stand-alone applications that communicate with Nushell
//! over stdin and stdout using a standardizes serialization framework to exchange
//! the typed data that Nushell commands utilize natively.
//!
//! A typical plugin application will define a struct that implements the [Plugin]
//! trait and then, in it's main method, pass that [Plugin] to the [serve_plugin]
//! function, which will handle all of the input and output serialization when
//! invoked by Nushell.
//!
//! ```
//! use nu_plugin::{EvaluatedCall, LabeledError, MsgPackSerializer, Plugin, serve_plugin};
//! use nu_protocol::{PluginSignature, Value};
//!
//! struct MyPlugin;
//!
//! impl Plugin for MyPlugin {
//! fn signature(&self) -> Vec<PluginSignature> {
//! todo!();
//! }
//! fn run(
//! &mut self,
//! name: &str,
//! config: &Option<Value>,
//! call: &EvaluatedCall,
//! input: &Value
//! ) -> Result<Value, LabeledError> {
//! todo!();
//! }
//! }
//!
//! fn main() {
//! serve_plugin(&mut MyPlugin{}, MsgPackSerializer)
//! }
//! ```
//!
//! Nushell's source tree contains a
//! [Plugin Example](https://github.com/nushell/nushell/tree/main/crates/nu_plugin_example)
//! that demonstrates the full range of plugin capabilities.
mod plugin;
mod protocol;
mod serializers;
pub use plugin::{get_signature, serve_plugin, Plugin, PluginDeclaration};
pub use protocol::{EvaluatedCall, LabeledError, PluginResponse};
pub use serializers::{json::JsonSerializer, msgpack::MsgPackSerializer, EncodingType};