#create_params

🏭 Macro

#[create_params($struct_name, $op(...) = excluding_id())]

This macro generates a new struct which can be used as parameters for creating a new entity. The generated struct’s fields are the same as the entity but without the ID field by default. The following table describes the operations that can be used in the macro:

operation	description
all()	includes all fields from entity (including ID)
excluding_id()	includes all fields except the ID field
only(…)	will only contain these fields
excluding(…)	includes all fields except these fields

📝 Macro Example:

use repox::Entity;

#[derive(Debug, Clone, PartialEq, Entity)]
#[create_params(PostParams)] // <- create with default `excluding_id()`
pub struct Post {
    pub id: u64,
    pub author_id: u32,
    pub data: String,
}

// It can be used by repositories to create new entities
async fn create_sample_post(
    repository: &impl repox::CreateWith<Post, PostParams>,
    author_id: u32
) -> Result<Post, anyhow::Error> {
    repository.create_with(PostParams { // <- missing `id` field since
        author_id,                      // we used `excluding_id()`
        data: "Sample Post".into(),
    }).await
}

🔬 Macro Details:

Here is the same example, but, without using the macro and implementing it ourselves. This highlights the fact that this macro is just a convenient way to implement the CreateWith<T, P> trait for a freshly minted structure with the same fields as the entity, but without the ID field by default. There is no magic here 🧙‍♂️!

use repox::Entity;

#[derive(Debug, Clone, PartialEq, Entity)]
pub struct Post {
    pub id: u64,
    pub author_id: u32,
    pub data: String,
}

// This is the exact same structure the macro above would generate
#[derive(Debug, Clone)]
pub struct PostParams {
    pub author_id: u32,
    pub data: String,
}

// Parameters need to implement `Creatable` for the entity
// they are compatible with.  For now this trait is empty,
// but in the future it may contain some useful functionality.
impl ::repox::Creatable<Post> for PostParams {}

// It can be used by repositories to create new entities
async fn create_sample_post(
    repository: &impl repox::CreateWith<Post, PostParams>,
    author_id: u32
) -> Result<Post, anyhow::Error> {
    repository.create_with(PostParams { // <- missing `id` field since
        author_id,                      // we used `excluding_id()`
        data: "Sample Post".into(),
    }).await
}

all()

📝 Macro Example:

use repox::Entity;

#[derive(Debug, Clone, PartialEq, Entity)]
#[create_params(PostParams, all())]
pub struct Post {
    pub id: u64,
    pub author_id: u32,
    pub data: String,
}

// All of the fields are included
let post = PostParams { id: 100, author_id: 1, data: "Hello World".into() };

excluding(...)

📝 Macro Example:

use repox::Entity;

#[derive(Debug, Clone, PartialEq, Entity)]
#[create_params(PostPlaceholder, excluding(id, data))]
pub struct Post {
    pub id: u64,
    pub author_id: u32,
    pub data: String,
}

// only has `author_id` since we excluded `id` and `data`
let post = PostPlaceholder { author_id: 1 };

only(...)

📝 Macro Example:

use repox::Entity;

#[derive(Debug, Clone, PartialEq, Entity)]
#[create_params(AnonPostData, only(data))]
pub struct Post {
    pub id: u64,
    pub author_id: u32,
    pub data: String,
}

// only has `data` field
let post = AnonPostData { data: "You too can example.".into() };