El - tree set using setCheckedNodessetCheckedKeys default check nodes, and a new check through setChecked specified node

Achieve the goal: When generating el-tree, select some of these options by default; or when selecting an option, select another option at the same time.

Achievement effect:

When generating a tree structure, two of these options are checked by default.

When one option is checked, the other option is also checked.

Implementation method:

First, set the default check when generating el-tree: two methods

1. Setting through node

setCheckedNodes

Set the currently checked node, use this method must set the node-key attribute

(nodes) Receive an array of checked node data

setCheckedNodes() {this.$refs.tree.setCheckedNodes([{id: 5,label: 'Secondary 2-1'}, {id: 9,label: 'Level 3 1-1-1'}]);},

2. Set by key: the inside is an array

setCheckedKeys

Set the currently checked node through keys, the node-key attribute must be set to use this method

(keys, leafOnly) receives two parameters, 1. The array of keys of the selected node 2. The parameter of boolean type, if it is true, only the selected state of the leaf node is set, the default valueis false

setCheckedKeys() {this.$refs.tree.setCheckedKeys([3, 5]);},

Second, when one option is checked, another option is also checked by default

The event triggered by checking an option is:

check-change

Callback when the selected state of the node changes

There are three parameters, in order: the object corresponding to the node in the array passed to the data attribute, whether the node itself is selected, and whether there is a selected node in the subtree of the node

Another option is also checked by default:

setChecked

Set the check state of a node through key / data, the node-key attribute must be set to use this method

(key/data, checked, deep) Receive three parameters, 1. Check the key or data of the node 2. boolean type, whether the node is selected 3. boolean type, whether to set the child node, the default is false

handleCheckChange(data, checked, indeterminate) {checked ? this.aMethods(data, true) : this.aMethods(data, false)},aMethods(item,bool){if(bool){this.$refs.tree.setChecked(5, true)}else{this.$refs.tree.setChecked(5, false)}}

This achieves the above effect.For more information, please refer to the Element official website.

Let me introduce myself first. The editor graduated from Shanghai Jiaotong University in 2013. I worked in a small company and went to big factories such as Huawei and OPPO. I joined Alibaba in 2018, until now.I know that most junior and intermediate java engineers want to upgrade their skills, they often need to explore their own growth or sign up to study, but for training institutions, the tuition fee is nearly 10,000 yuan, which is really stressful.Self-learning that is not systematic is very inefficient and lengthy, and it is easy to hit the ceiling and the technology stops.Therefore, I collected a "full set of learning materials for java development" for everyone. The original intention is also very simple. I hope to help friends who want to learn by themselves but don't know where to start, and at the same time reduce everyone's burden.Add the business card below to get a full set of learning materials