分类文章列表

模板

请参见代码仓库的templates/frontend/topic_list.html

视图类

handler

数据库操作

以下代码位于 src/db/topic.rs

list_by_cat()的定义如下：

pub async fn list_by_cat(client: &Client, page: u32, cat_id: i32) -> Result<Paginate<Vec<TopicList>>> {
    list_by_condition(client, page, Some("category_id=$1"), Some(&[&cat_id])).await
}

它调用的是 list_by_condition()：

async fn list_by_condition(client:&Client, page:u32, condition:Option<&str>, params:Option<&[&(dyn ToSql + Sync)]>) -> Result<Paginate<Vec<TopicList>>> {
    let sql = "SELECT id,title,category_id,summary,hit,dateline,is_del,category_name FROM v_topic_cat_list WHERE is_del=false %CONDITION% ORDER BY id DESC ";
    let condition = match condition {
        Some(c) => format!(" AND {}", c),
        None => "".to_string(),
    };
    let sql = sql.replace("%CONDITION%", &condition);
    let sql=format!("{} LIMIT {} OFFSET {}",sql, DEFAULT_PAGE_SIZE, DEFAULT_PAGE_SIZE as u32 * page);
    let count_sql = "SELECT COUNT(*) FROM v_topic_cat_list WHERE is_del=false %CONDITION%";
    let count_sql = count_sql.replace("%CONDITION%", &condition);
    let params = params.unwrap_or(&[]);
    super::pagination(client, &sql, &count_sql, params, page).await
}

list_by_condition()用于指定条件的查询，list_by_cat()的条件是分类ID，而我们上一章使用的 list()是无条件的，所以该函数也改用list_by_condition()：

pub async fn list(client: &Client, page: u32) -> Result<Paginate<Vec<TopicList>>> {
    list_by_condition(client, page, None, None).await
}

请参见源码仓库的src/handler/frontend/mod.rs。

本章代码位于08/分类文章列表分支。