forked from extern/nushell
055edd886d
# Description
As title, we can't provide examples for plugin commands, this pr would
make it possible
# User-Facing Changes
Take plugin `nu-example-1` as example:
```
❯ nu-example-1 -h
PluginSignature test 1 for plugin. Returns Value::Nothing
Usage:
> nu-example-1 {flags} <a> <b> (opt) ...(rest)
Flags:
-h, --help - Display the help message for this command
-f, --flag - a flag for the signature
-n, --named <String> - named string
Parameters:
a <int>: required integer value
b <string>: required string value
(optional) opt <int>: Optional number
...rest <string>: rest value string
Examples:
running example with an int value and string value
> nu-example-1 3 bb
```
The examples session is newly added.
## Basic idea behind these changes
when nushell query plugin signatures, plugin just returns it's signature
without any examples, so nushell have no idea about the examples of
plugin commands.
To adding the feature, we just making plugin returns it's signature with
examples.
Before:
```
1. get signature
---------------->
Nushell ------------------ Plugin
<-----------------
2. returns Vec<Signature>
```
After:
```
1. get signature
---------------->
Nushell ------------------ Plugin
<-----------------
2. returns Vec<PluginSignature>
```
When writing plugin signature to $nu.plugin-path:
Serialize `<PluginSignature>` rather than `<Signature>`, which would
enable us to serialize examples to `$nu.plugin-path`
## Shortcoming
It's a breaking changes because `Plugin::signature` is changed, and it
requires plugin authors to change their code for new signatures.
Fortunally it should be easy to change, for rust based plugin, we just
need to make a global replace from word `Signature` to word
`PluginSignature` in their plugin project.
Our content of plugin-path is really large, if one plugin have many
examples, it'd results to larger body of $nu.plugin-path, which is not
really scale. A solution would be save register information in other
binary formats rather than `json`. But I think it'd be another story.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
31 lines
1.6 KiB
Rust
31 lines
1.6 KiB
Rust
use nu_plugin::{serve_plugin, MsgPackSerializer};
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use nu_plugin_example::Example;
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fn main() {
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// When defining your plugin, you can select the Serializer that could be
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// used to encode and decode the messages. The available options are
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// MsgPackSerializer and JsonSerializer. Both are defined in the serializer
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// folder in nu-plugin.
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serve_plugin(&mut Example {}, MsgPackSerializer {})
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// Note
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// When creating plugins in other languages one needs to consider how a plugin
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// is added and used in nushell.
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// The steps are:
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// - The plugin is register. In this stage nushell calls the binary file of
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// the plugin sending information using the encoded PluginCall::PluginSignature object.
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// Use this encoded data in your plugin to design the logic that will return
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// the encoded signatures.
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// Nushell is expecting and encoded PluginResponse::PluginSignature with all the
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// plugin signatures
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// - When calling the plugin, nushell sends to the binary file the encoded
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// PluginCall::CallInfo which has all the call information, such as the
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// values of the arguments, the name of the signature called and the input
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// from the pipeline.
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// Use this data to design your plugin login and to create the value that
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// will be sent to nushell
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// Nushell expects an encoded PluginResponse::Value from the plugin
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// - If an error needs to be sent back to nushell, one can encode PluginResponse::Error.
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// This is a labeled error that nushell can format for pretty printing
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}
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