Module serializer 

DRF-style serializer layer — #[derive(Serializer)] + serializer::ModelSerializer. Typed JSON output from model instances with field control and validation. DRF-style serializer layer — typed JSON output from model instances.

A serializer is a Rust struct that maps a Model instance to a JSON-ready shape, with per-field control over what is included, renamed, or excluded.

Quick start

use rustango::Serializer;
use rustango::serializer::ModelSerializer;

#[derive(Serializer, serde::Deserialize, Default)]
#[serializer(model = Post)]
pub struct PostSerializer {
    pub id:         i64,
    pub title:      String,
    #[serializer(read_only)]
    pub created_at: chrono::DateTime<chrono::Utc>,
    #[serializer(write_only)]
    pub secret:     String,
    #[serializer(source = "body")]
    pub content:    String,
    #[serializer(skip)]
    pub tag_ids:    Vec<i64>,   // set manually: s.tag_ids = post.tags_m2m().all(&pool).await?
}

// Serialize:
let s = PostSerializer::from_model(&post);
let json = s.to_value();

// Serialize many:
let json_array = PostSerializer::many_to_value(&posts);

Field attributes

Attribute	Effect on from_model	Effect on JSON output	Effect on writable_fields
(none)	mapped from model	included	yes
read_only	mapped from model	included	no
write_only	Default::default()	excluded	yes
source = "x"	mapped from model.x	included	yes
skip	Default::default()	included	no

Nested serializers

For v0.20.x, nested objects require #[serializer(skip)] — set the field manually after calling from_model:

let mut s = PostSerializer::from_model(&post);
s.author = AuthorSerializer::from_model(post.author.value().expect("loaded"));

Full automatic nested support (#[serializer(nested)] with FK loading) is planned for a future slice.

Validation

Add cross-field validation as an inherent method on the serializer struct:

impl PostSerializer {
    pub fn validate(&self) -> Result<(), rustango::forms::FormErrors> {
        let mut errors = rustango::forms::FormErrors::default();
        if self.title.is_empty() {
            errors.add("title", "title cannot be empty");
        }
        if errors.is_empty() { Ok(()) } else { Err(errors) }
    }
}

Traits

ModelSerializer

Core serializer trait. Implemented by #[derive(Serializer)] structs.