实现TodoItem

本章代码在06/待办事项分支。

模型定义

首先，我们在src/model.rs定义相关模型：

/// 待办事项模型
#[derive(PostgresMapper, Serialize)]
#[pg_mapper(table = "todo_item")]
pub struct TodoItem {
    pub id: i32,
    pub title: String,
    pub checked: bool,
    pub list_id: i32,
}

/// 待办事项新ID模型
#[derive(PostgresMapper, Serialize)]
#[pg_mapper(table = "todo_item")]
pub struct TodoItemID {
    pub id: i32,
}

表单定义

接着，我们在src/form.rs定义相关表单：

数据库操作

然后，我们实现其数据库操作。创建src/db/todo_item.rs文件，并输入以下代码：（别忘了在src/db/mod.rs中声明todo_item模块）

pub async fn all(client: &Client, list_id: i32) -> Result<Vec<TodoItem>> {
    let result: Vec<TodoItem> = super::query(
        client,
        "SELECT id,title,checked,list_id FROM todo_item WHERE list_id=$1 ORDER BY id ASC",
        &[&list_id],
    )
    .await?;
    Ok(result)
}

pub async fn find(client: &Client, list_id: i32, item_id: i32) -> Result<TodoItem> {
    let result: TodoItem = super::query_one(
        client,
        "SELECT id,title,checked,list_id FROM todo_item WHERE id=$1 AND list_id=$2",
        &[&item_id, &list_id],
    )
    .await?;
    Ok(result)
}

pub async fn check(client: &Client, list_id: i32, item_id: i32) -> Result<bool> {
    let result = super::execute(
        client,
        "UPDATE todo_item SET checked=true WHERE id=$1 AND list_id=$2 AND checked=false",
        &[&item_id, &list_id],
    )
    .await?;
    Ok(result > 0)
}

pub async fn delete(client: &Client, list_id: i32, item_id: i32) -> Result<bool> {
    let result = super::execute(
        client,
        "DELETE FROM todo_item WHERE id=$1 AND list_id=$2",
        &[&item_id, &list_id],
    )
    .await?;
    Ok(result > 0)
}

pub async fn create(client: &Client, frm: form::CreateTodoItem) -> Result<TodoItemID> {
    let result = query_one(
        client,
        "INSERT INTO todo_item (title, checked, list_id) VALUES ($1,$2,$3) RETURNING id",
        &[&frm.title, &false, &frm.list_id],
    )
    .await?;
    Ok(result)
}

从代码可以看出，都是对父模块相关方法的调用，这里不再赘述。

handler 的定义

同样的，我们创建src/handler/todo_item.rs，并输入以下内容：

pub async fn create(
    Extension(state): Extension<AppState>,
    Json(payload): Json<form::CreateTodoItem>,
) -> HandlerResult<TodoItemID> {
    let handler_name = "todo_item_create";
    let client = get_client(&state, handler_name).await?;
    let result = todo_item::create(&client, payload)
        .await
        .map_err(log_error(handler_name.to_string()))?;
    Ok(Json(Response::ok(result)))
}

pub async fn all(
    Extension(state): Extension<AppState>,
    Path(list_id): Path<i32>,
) -> HandlerResult<Vec<TodoItem>> {
    let handler_name = "todo_item_all";
    let client = get_client(&state, handler_name).await?;
    let result = todo_item::all(&client, list_id)
        .await
        .map_err(log_error(handler_name.to_string()))?;
    Ok(Json(Response::ok(result)))
}

pub async fn find(
    Extension(state): Extension<AppState>,
    Path((list_id, item_id)): Path<(i32, i32)>,
) -> HandlerResult<TodoItem> {
    let handler_name = "todo_item_find";
    let client = get_client(&state, handler_name).await?;
    let result = todo_item::find(&client, list_id, item_id)
        .await
        .map_err(log_error(handler_name.to_string()))?;
    Ok(Json(Response::ok(result)))
}

pub async fn check(
    Extension(state): Extension<AppState>,
    Path((list_id, item_id)): Path<(i32, i32)>,
) -> HandlerResult<bool> {
    let handler_name = "todo_item_check";
    let client = get_client(&state, handler_name).await?;
    let result = todo_item::check(&client, list_id, item_id)
        .await
        .map_err(log_error(handler_name.to_string()))?;
    Ok(Json(Response::ok(result)))
}
pub async fn delete(
    Extension(state): Extension<AppState>,
    Path((list_id, item_id)): Path<(i32, i32)>,
) -> HandlerResult<bool> {
    let handler_name = "todo_item_delete";
    let client = get_client(&state, handler_name).await?;
    let result = todo_item::delete(&client, list_id, item_id)
        .await
        .map_err(log_error(handler_name.to_string()))?;
    Ok(Json(Response::ok(result)))
}

至此，TodoItem 已经开发完成，也意味着整个 Todo 服务开发完成。