Question

This is the db structure

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/colorPrimary"
    android:orientation="vertical">

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <android.support.v7.widget.CardView
            android:id="@+id/mRequestCard"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:elevation="100dp"
            android:orientation="horizontal"
            app:cardBackgroundColor="@color/colorWhite"
            app:cardCornerRadius="3dp">

            <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <View
                    android:id="@+id/vDivisor"
                    android:layout_width="match_parent"
                    android:layout_height="2dp"
                    android:background="@color/colorGreen" />
                ...

            </RelativeLayout>

        </android.support.v7.widget.CardView>

    </android.support.v4.widget.NestedScrollView>


    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_alignParentRight="true"
        android:layout_marginRight="10dp"
        android:backgroundTint="@color/colorAccent"
        android:scaleType="centerCrop"
        android:src="@drawable/ic_launcher"
        app:layout_anchor="@id/mRequestCard"
        app:layout_anchorGravity="right|end|bottom" />

</RelativeLayout>

我使用的代码就是这个，

[
  {
    text: 'Parent 1',
    href: '#parent1',
    tags: ['4'],
    nodes: [
      {
        text: 'Child 1',
        href: '#child1',
        tags: ['2'],
        nodes: [
          {
            text: 'Grandchild 1',
            href: '#grandchild1',
            tags: ['0']
          },
          {
            text: 'Grandchild 2',
            href: '#grandchild2',
            tags: ['0']
          }
        ]
      },
      {
        text: 'Child 2',
        href: '#child2',
        tags: ['0']
      }
    ]
  },
  {
    text: 'Parent 2',
    href: '#parent2',
    tags: ['0']
  },
  {
    text: 'Parent 3',
    href: '#parent3',
     tags: ['0']
  }
]

我得到的输出： output

上面的代码只提供了一个级别，但我想深入了解。如何格式化循环以完成它？

Answer 1

你需要编写一个递归函数来实现它。您可以在Parent - Child - Grand Child category Markup in Codeigniter view

找到答案

Answer 2

尝试以下方法：

public function getCategoryTree()
{
    $query = $this->db->select('id,parent_id,name')
        ->order_by('parent_id','asc')
        ->get('categories');

    if( $query->num_rows() > 0 )
    {
        $result = $query->result_array();

        foreach( $result as $k => $v )
        {
            $count = 0;
            $v['href'] = '#'. strtolower(str_replace(' ', '', $v['name']));

            foreach( $result as $k2 => $v2 )
            {
                // if child has this parent, count
                if( $v['id'] == $v2['parent_id'] )
                    $count++;
            }

            if( $count )
                $v['tags'] = array((string)$count);

            $mod[] = $v;
        }

        $tree = $this->buildTree($mod);

        $this->key_unset_recursive( $tree, 'id' );
        $this->key_unset_recursive( $tree, 'parent_id' );

        echo json_encode( $tree, JSON_PRETTY_PRINT );
    }

}

public function buildTree( array $elements, $parentId = 0 )
{
    $branch = array();

    foreach( $elements as $element )
    {
        if( $element['parent_id'] == $parentId )
        {
            $children = $this->buildTree($elements, $element['id']);

            if( $children )
            {
                $element['nodes'] = $children;
            }

            $branch[] = $element;
        }
    }

    return $branch;
}

public function key_unset_recursive( &$array, $remove )
{
    foreach( $array as $key => &$value )
    {
        if( $key === $remove )
        {
            unset( $array[$key] );
        }

        else if( is_array( $value ) )
        {
            $this->key_unset_recursive( $value, $remove );
        }
    }
}

codeigniter树视图构建数据

2 个答案: