clap

Simple Struct Descriptor

Easy pretty print your Rust struct into single element or list

TLDR

use descriptor::{object_describe_to_string, Descriptor};

#[derive(Descriptor)]
struct Foo {
    first_field: String,
    int_field: i32,
}

fn main() {
    println!("{}", object_describe_to_string(Foo{first_field: "foo", int_field: 1}).unwrap());
}

Will print or simple description:

First Field: foo
Int Field:   1

Or for table:

FIRST_FIELD INT_FIELD
foo         1

The #[derive(Descriptor)] will auto implement the Describe Trait for the Struct

Struct Attributes:

#[descriptor(into = AnotherStruct)]

Will use another struct to describe the struct. The From or Into Trait should be implemented and AnotherStruct should implement the Describe trait

#[descriptor(headers = &["HEADER_1"])]

Will override the default generated header list

#[descriptor(map = some_func)]

A function hook that act on the entire row with the struct as context. The function need to return a String

fn some_func(contextual_struct: &A, cell: String) -> String {
    match contextual_struct.is_selected {
        true => cell.green(),
        false => cell.reset(),
    }
    .to_string()
}

Field Attributes

#[descriptor(skip)]

Will skip this field on any context

#[descriptor(skip_header)]

Will skip this field on the auto-generated default headers list

#[descriptor(skip_description)]

Will skip this field on the description context

#[descriptor(output_table)]

On a description context, will display a list into a table, example:

#[derive(Descriptor)]
struct A {
    #[descriptor(output_table)]
    history: Vec<AnotherStruct>,
}

History:
  STATE   VALUE
  test    value

#[descriptor(resolve_option)]

Should we resolve option, usefull with the map attribute

#[descriptor(into = AnotherStruct)]

Same as into in the Struct Level but for a specific Field

#[descriptor(map=to_string)]

Use a function in order to transform the value, function will receive the field by reference. Assume that the return function is a scalar type.

#[descriptor(map=to_string, method)]

Use a method instead of a public function.

#[descriptor(map=to_another_struct, method, into=AnotherStruct)]

Use a method instead of From to go on another struct.

#[descriptor(rename_header="HEADER_NAME")]

Rename a header field

#[descriptor(rename_description="Another Description")]

Rename a description value for Enum. TODO(aca): Implement this for description field ?

#[descriptor(flatten)]

Flatten a struct into another one

#[descriptor(additional_struct = ComputedStruct)]

Add another other field into the struct. ComputedStruct must impl the From Trait