Crate rschema

Expand description

Rschema

Rschema provides a macro for generating JSON schemas from Rust structures.

Example

use rschema::{
    Schema,
    Schematic,
};
 
#[derive(Debug, Schematic)]
#[rschema(additional_properties)]
struct Data {
    #[rschema(field(
        title = "Test flag",
        description = "The flag whether for test.",
    ))]
    test_flag: bool,
}
 
#[derive(Debug, Schematic)]
struct AppConfig {
    #[rschema(
        field(
            title = "Application name",
        ),
        required,
    )]
    name: String,
 
    #[rschema(
        field(
            title = "Application version",
            pattern = r"^(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)$",
        ),
        required,
    )]
    version: String,
 
    #[rschema(field(
        title = "Application data",
        description = "This property is optional.",
    ))]
    other_data: Data,
}
 
fn main() -> rschema::Result<()> {
    Schema::new::<AppConfig>("Application Config")
        .write_pretty("../schemas/config.schema.json")?;
 
    Ok(())
}

This code generates the following JSON schema file.

{
  "title": "Application Config",
  "type": "object",
  "properties": {
    "name": {
      "title": "Application name",
      "type": "string"
    },
    "version": {
      "title": "Application version",
      "type": "string",
      "pattern": "^(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)$"
    },
    "other_data": {
      "title": "Application data",
      "type": "object",
      "properties": {
        "test_flag": {
          "title": "Test flag",
          "description": "The flag whether for test.",
          "type": "boolean"
        }
      },
      "additionalProperties": true
    }
  },
  "required": [
    "name",
    "version"
  ],
  "additionalProperties": false
}

Attributes

Struct attributes

This attribute is available only for structs or struct variants.

Attribute	Type	Meaning
`additional_properties`	`bool`	Whether to allow properties not included in `properties`.

Field attributes

Common

All types have the following attributes.

Top-level attribute	Sub attribute	Type	Meaning
`field`	`title`	`String`	Required. The short description about the field.
	`description`	`String`	The more lengthy description about the field.
`required`		`bool`	Whether the property is required or not.

Dedicated

Each types have dedicated attributes.

Using another type’s attributes does not raise errors, but no meaning.

`String`

Attribute	Type	Meaning
`min_length`	`u64`	The minimum length.
`max_length`	`u64`	The maximum length.
`pattern`	`String`	The regular expression to restrict value.
`format`	`String`	The basic semantic identification of certain kinds of string values that are commonly used.

`Number`

Attribute	Type	Meaning
`minimum`	`i64`	Specify the minimum of the range.
`maximum`	`i64`	Specify the maximum of the range.
`multiple_of`	`i64`	Numbers can be restricted to a multiple of a given number.
`exclusive_minimum`	`i64`	Specify the exclusive minimum of the range.
`exclusive_maximum`	`i64`	Specify the exclusive maximum of the range.