从树中删除选定的节点

Posted 2023-02-21

【中文标题】从树中删除选定的节点

【英文标题】：Remove selected node from Tree

【发布时间】：2017-06-01 06:09:56

【问题描述】：

我正在使用 angular-tree-component (https://angular2-tree.readme.io) 在 Angular2 应用程序中显示一棵树。

我需要让用户能够选择树中的任何节点并将其删除。这应该删除选定的节点及其所有子节点（如果它是叶节点，则只是节点）。当用户完成后，修剪的树将被发送到服务器并保存在那里。

在下面的示例中，用户选择“节点 1-2”并单击删除。这会从视图中删除“节点 1-2”、“节点 1”和“节点 2”，并更新底层 javascript 对象。然后，用户可以单击另一个按钮（例如，保存）将更新的对象保存在服务器上。

为了实现这一点，我编写了以下代码，该代码在单击删除按钮时调用。我存储所选节点的 id，然后遍历整个树以找到该 id。当 id 匹配时，我使用 'delete' 关键字删除 'id' 和 'text'。但是，“删除子项”不起作用。

deleteSelectedNode()  
    //Get the node which was selected by the user  
    let nodeToDelete: TreeNode = this.myService.getActiveNode();
    //id will be unique, can be used to identify the node
    let idToDelete = nodeToDelete.data.id; 
    this.traverseTree(this.nodes[0], idToDelete);
  

  traverseTree(obj, idToDelete: string) 

    for (var k in obj) 
      if (typeof obj[k] == "object" && obj[k] !== null) 
        this.traverseTree(obj[k], idToDelete);
      

      else 
        if (k === 'id') 
          let id = obj[k];
          if (id === idToDelete) 
            console.log('ID Matched ' + id);
            delete obj['id'];
            delete obj['text'];
            delete obj['children']; 
            break;
          
         
      
    
  

下面是渲染树的 JSON。

        "children": [
            
                "children": [
                    
                        "text": "Node 1",
                        "id": "A493"
                    ,
                    
                        "text": "Node 2",
                        "id": "A494"
                    
                ],
                "text": "Node 1-2",
                "id": "A491"
            ,
            
                "children": [
                    
                        "children": [
                            
                                "text": "Node 3",
                                "id": "A5ab"
                            ,
                            
                                "text": "Node 4",
                                "id": "A5ac"
                            ,
                            
                                "text": "Node 5",
                                "id": "A5ad"
                            ,
                            
                                "text": "Node 6",
                                "id": "A5ae"
                            ,
                            
                                "text": "Node 7",
                                "id": "A5af"
                            ,
                            
                                "text": "Node 8",
                                "id": "A5b0"
                            ,
                            
                                "text": "Node 9",
                                "id": "A5b1"
                            ,
                            
                                "text": "Node 10",
                                "id": "A5b2"
                            ,
                            
                                "text": "Node 11",
                                "id": "A5b3"
                            ,
                            
                                "text": "Node 12",
                                "id": "A5b4"
                            ,
                            
                                "text": "Node 13",
                                "id": "A6da"
                            ,
                            
                                "text": "Node 14",
                                "id": "A6db"
                            
                        ],
                        "text": "Node 1-14",
                        "id": "A495"
                    ,
                    
                        "children": [
                            
                                "text": "Node 15",
                                "id": "A6dc"
                            ,
                            
                                "text": "Node 16",
                                "id": "A6dd"
                            ,
                            
                                "text": "Node 17",
                                "id": "A6de"
                            ,
                            
                                "text": "Node 18",
                                "id": "A6df"
                            ,
                            
                                "text": "Node 19",
                                "id": "A6e0"
                            ,
                            
                                "text": "Node 20",
                                "id": "A6e1"
                            ,
                            
                                "text": "Node 21",
                                "id": "A6e2"
                            ,
                            
                                "text": "Node 22",
                                "id": "A6e3"
                            
                        ],
                        "text": "Node 15-22",
                        "id": "A496"
                    ,
                    
                        "text": "Node 23",
                        "id": "A497"
                    ,
                    
                        "text": "Node 24",
                        "id": "A498"
                    
                ],
                "text": "Node 23-24",
                "id": "A492"
            
        ],
        "text": "Node 1-24",
        "id": "A490"
    

如何删除整个节点，包括子节点？另外，有没有更好的方法来做到这一点？

【参考方案1】：

您可以通过父母参考轻松做到这一点

deleteNode() 
    let nodeToDelete: TreeNode = this.tree.treeModel.getActiveNode();
    if (nodeToDelete.level === 1) 
      this.nodes = this.nodes.filter((n) => n.id !== nodeToDelete.id);
     else 
      nodeToDelete.parent.children = nodeToDelete.parent.children.filter((n) => n.id !== nodeToDelete.id);