Struct ResourceMap 

pub struct ResourceMap { /* private fields */ }

Builder for constructing JSON resource representations with conditional field support.

ResourceMap collects field name-value pairs and supports conditional inclusion via when(), unless(), merge_when(), and when_some(). Fields are output in insertion order.

Example

use ferro_rs::ResourceMap;
use serde_json::json;

let value = ResourceMap::new()
    .field("id", json!(1))
    .field("name", json!("Alice"))
    .when("email", is_admin, || json!("alice@example.com"))
    .build();

Implementations

impl ResourceMap

pub fn new() -> Self

Create an empty resource map.

pub fn field(self, key: &str, value: impl Into<Value>) -> Self

Always include this field in the output.

pub fn when( self, key: &str, condition: bool, value: impl FnOnce() -> Value, ) -> Self

Include field only when condition is true. The value closure is only evaluated when the condition holds.

pub fn unless( self, key: &str, condition: bool, value: impl FnOnce() -> Value, ) -> Self

Include field only when condition is false (opposite of when).

pub fn merge_when( self, condition: bool, fields: impl FnOnce() -> Vec<(&'static str, Value)>, ) -> Self

Conditionally merge multiple fields at once. When the condition is true, all fields from the closure are included.

pub fn when_some<T: Serialize>(self, key: &str, value: &Option<T>) -> Self

Include field only if the Option is Some.

pub fn when_loaded<K, M>( self, key: &str, lookup_key: &K, map: &HashMap<K, M>, transform: impl FnOnce(&M) -> Value, ) -> Self

where K: Eq + Hash,

Include field if lookup_key exists in the given HashMap (belongs_to / has_one).

When the key is found, transform converts the value to JSON. When absent the field is omitted from output.

pub fn when_loaded_many<K, M>( self, key: &str, lookup_key: &K, map: &HashMap<K, Vec<M>>, transform: impl FnOnce(&[M]) -> Value, ) -> Self

where K: Eq + Hash,

Include field if lookup_key exists in the given HashMap<K, Vec<M>> (has_many).

When the key is found, transform receives the vec slice. When absent the field is omitted from output. An empty vec is still included (loaded but empty).

pub fn build(self) -> Value

Finalize into a JSON object, stripping fields marked as missing. Preserves insertion order.

Trait Implementations

impl Default for ResourceMap

fn default() -> Self

Returns the “default value” for a type.