Translation of this issue:

Element UI version

2.15.1

OS/Browsers version

mac

Vue version

2.6.10

Reproduction Link

https://elementui.github.io/issue-generator

Steps to reproduce

<template>
<div class=\"custom-tree-container\">

<el-button @click=\"add()\">testbutton</el-button>
<div class=\"block\">

<p>render-content</p>
<el-tree

:data=\"data\"
node-key=\"id\"

ref=\"sideTree\"
:expand-on-click-node=\"true\">

</el-tree>
</div>

</div>
</template>

<script>
export default {

data() {
return {

id: 0,
// data: this.$ store.state.sidebar .menu

data: [
{

id: 1,
label: 'nodea',

children: [
{

id: 3,
label: 'nodea3',

children: [{
id: 5,

label: 'nodea5',
}],

}, {
id: 4,

label: 'nodea4',
children: [],

}
],

}, {
id: 2,

label: 'nodeb',
children: {}

}
]

}
},

mounted() {
this.data.push ({

id: 117,
label: 'oooo',

children: [],
})

//  this.data.splice (1, 1)
console.log ('children:',  this.data [0].children[0].children)

this.data [0].children[0]. children.push ({
id: 817,

label: 'xxxx',
children: [],

})
//  console.log (\"data,\",  this.data )

},
methods: {

add() {
this.data [0].children[0]. children.push ({

id: 1017,
label: 'addxxxx',

children: [],
})

},
}

};
</script>

What is Expected?

1. After loading the page for the first time, you should be able to see the node xxxxx, but it doesn't
   Node OOo can be seen

What is actually happening?

1. We don't see node XXX, but we see node oooo
2. Click testbutton, and then you can see the nodes xxxxx and addxxxxx

数组的深度为1时的push,能够得到view的响应,但是深度为3时就得不到了view的响应,感觉很奇怪.

@element-bot Reproduction Link is https://jsfiddle.net/5pjnqs4u/5/

there are two ways two fix this problem:

1. set default-expand-all true
2. use PR Tree: Data may be changed before node is created. #20884 #20905

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.