thinkphp5实现无限级新闻分类

要实现无限级新闻分类，可以使用thinkphp5自带的树形结构扩展类库来实现。

1. 创建一个分类模型

在app\admin\model目录下创建一个NewsCategory.php模型文件。代码如下：

namespace app\admin\model;

use think\Model;
use think\Db;
use think\Tree;

class NewsCategory extends Model
{
    protected $name = 'news_category';

    public function getTree()
    {
        $list = Db::name($this->name)->order('sort_order')->select();
        $tree = new Tree();
        $tree->init($list);
        $tree = $tree->getTreeList($tree->getTreeArray(0), 'name');
        return $tree;
    }
}

2. 创建分类控制器

在app\admin\controller目录下创建一个NewsCategory.php控制器文件。代码如下：

namespace app\admin\controller;

use think\Controller;
use app\admin\model\NewsCategory as CategoryModel;

class NewsCategory extends Controller
{
    public function index()
    {
        $category_model = new CategoryModel();
        $tree = $category_model->getTree();
        $this->assign('tree', $tree);
        return $view->fetch();
    }

    public function add()
    {
        $category_model = new CategoryModel();
        $tree = $category_model->getTree();
        $this->assign('tree', $tree);
        return $view->fetch();
    }

    public function save()
    {
        $data = input('post.');
        $category_model = new CategoryModel();
        $result = $category_model->validate('NewsCategory')->save($data);
        if ($result === false) {
            $this->error($category_model->getError());
        } else {
            $this->success('添加成功', url('index'));
        }
    }

    public function edit($id)
    {
        $category_model = new CategoryModel();
        $category = $category_model->get($id);
        $tree = $category_model->getTree();
        $this->assign('tree', $tree);
        $this->assign('category', $category);
        return $view->fetch();
    }

    public function update($id)
    {
        $data = input('post.');
        $category_model = new CategoryModel();
        $result = $category_model->validate('NewsCategory')->save($data, ['id' => $id]);
        if ($result === false) {
            $this->error($category_model->getError());
        } else {
            $this->success('编辑成功', url('index'));
        }
    }

    public function delete($id)
    {
        $category_model = new CategoryModel();
        $category = $category_model->get($id);
        if (empty($category)) {
            $this->error('分类不存在');
        }
        $result = $category->delete();
        if ($result === false) {
            $this->error('删除失败');
        } else {
            $this->success('删除成功');
        }
    }
}

3. 创建分类列表视图

在app\admin\view\news_category目录下创建一个index.html视图文件。代码如下：

{extend name="layout/base"}

{block name="content"}
<div class="row">
    <div class="col-md-12">
        <div class="panel panel-default">
            <div class="panel-heading">
                <h3 class="panel-title">分类列表</h3>
            </div>
            <div class="panel-body">
                <table class="table table-striped table-bordered table-hover">
                    <thead>
                        <tr>
                            <th>ID</th>
                            <th>分类名称</th>
                            <th>排序</th>
                            <th>操作</th>
                        </tr>
                    </thead>
                    <tbody>
                        {volist name="tree" id="vo"}
                        <tr>
                            <td>{$vo.id}</td>
                            <td>{$vo.name}</td>
                            <td>{$vo.sort_order}</td>
                            <td>
                                <a href="{:url('edit', ['id' => $vo.id])}" class="btn btn-xs btn-primary"><i class="fa fa-edit"></i> 编辑</a>
                                <a href="{:url('delete', ['id' => $vo.id])}" class="btn btn-xs btn-danger confirm"><i class="fa fa-trash"></i> 删除</a>
                            </td>
                        </tr>
                        {/volist}
                    </tbody>
                </table>
            </div>
        </div>
    </div>
</div>
{/block}

4. 创建分类添加/编辑视图

在app\admin\view\news_category目录下创建一个add.html和edit.html视图文件。代码如下：

add.html

{extend name="layout/base"}

{block name="content"}
<div class="row">
    <div class="col-md-12">
        <div class="panel panel-default">
            <div class="panel-heading">
                <h3 class="panel-title">添加分类</h3>
            </div>
            <div class="panel-body">
                <form role="form" method="post" action="{:url('save')}">
                    <div class="form-group">
                        <label for="name">分类名称</label>
                        <input type="text" class="form-control" name="name" id="name" placeholder="请输入分类名称" required>
                    </div>
                    <div class="form-group">
                        <label for="parent_id">上级分类</label>
                        <select class="form-control" name="parent_id" id="parent_id">
                            <option value="0">顶级分类</option>
                            {volist name="tree" id="vo"}
                            <option value="{$vo.id}">{$vo.title}</option>
                            {/volist}
                        </select>
                    </div>
                    <div class="form-group">
                        <label for="sort_order">排序</label>
                        <input type="text" class="form-control" name="sort_order" id="sort_order" placeholder="请输入排序" required>
                    </div>
                    <button type="submit" class="btn btn-primary">添加</button>
                    <button type="reset" class="btn btn-default">重置</button>
                </form>
            </div>
        </div>
    </div>
</div>
{/block}

edit.html

{extend name="layout/base"}

{block name="content"}
<div class="row">
    <div class="col-md-12">
        <div class="panel panel-default">
            <div class="panel-heading">
                <h3 class="panel-title">编辑分类</h3>
            </div>
            <div class="panel-body">
                <form role="form" method="post" action="{:url('update', ['id' => $category->id])}">
                    <div class="form-group">
                        <label for="name">分类名称</label>
                        <input type="text" class="form-control" name="name" id="name" placeholder="请输入分类名称" value="{$category->name}" required>
                    </div>
                    <div class="form-group">
                        <label for="parent_id">上级分类</label>
                        <select class="form-control" name="parent_id" id="parent_id">
                            <option value="0">顶级分类</option>
                            {volist name="tree" id="vo"}
                            <option value="{$vo.id}" {if condition="$category->parent_id == $vo.id"}selected{/if}>{$vo.title}</option>
                            {/volist}
                        </select>
                    </div>
                    <div class="form-group">
                        <label for="sort_order">排序</label>
                        <input type="text" class="form-control" name="sort_order" id="sort_order" placeholder="请输入排序" value="{$category->sort_order}" required>
                    </div>
                    <button type="submit" class="btn btn-primary">保存</button>
                    <button type="reset" class="btn btn-default">重置</button>
                </form>
            </div>
        </div>
    </div>
</div>
{/block}

5. 创建分类验证器

在app\admin\validate目录下创建一个NewsCategory.php验证器文件。代码如下：

namespace app\admin\validate;

use think\Validate;

class NewsCategory extends Validate
{
    protected $rule = [
        'name' => 'require|max:50',
        'parent_id' => 'integer',
        'sort_order' => 'integer',
    ];

    protected $message = [
        'name.require' => '分类名称不能为空',
        'name.max' => '分类名称不能超过50个字符',
        'parent_id.integer' => '上级分类ID必须是整数',
        'sort_order.integer' => '排序必须是整数',
    ];

    protected $scene = [
        'save' => ['name', 'parent_id', 'sort_order'],
        'update' => ['name', 'parent_id', 'sort_order'],
    ];
}

6. 创建分类数据表

在数据库中创建一个news_category表，包含id、name、parent_id、sort_order四个字段。其中，parent_id为0表示顶级分类，非0表示上级分类的id。

至此，无限级新闻分类的实现就完成了。