especially the sentence return resolve ([{name: "region1"}, {name:" region2"}]), I don"t understand what return returns, resolve is passed in as a parameter, but where is the definition of resolve and how to use this method? please advise
< el-tree
: props= "props"
: load= "loadNode"
lazy
show-checkbox
@ check-change= "handleCheckChange" >
< / el-tree >
< script >
export default {
data() {
return {
props: {
label: "name",
children: "zones"
},
count: 1
};
},
methods: {
handleCheckChange(data, checked, indeterminate) {
console.log(data, checked, indeterminate);
},
handleNodeClick(data) {
console.log(data);
},
loadNode(node, resolve) {
if (node.level === 0) {
return resolve([{ name: "region1" }, { name: "region2" }]);
}
if (node.level > 3) return resolve([]);
var hasChild;
if (node.data.name === "region1") {
hasChild = true;
} else if (node.data.name === "region2") {
hasChild = false;
} else {
hasChild = Math.random() > 0.5;
}
setTimeout(() => {
var data;
if (hasChild) {
data = [{
name: "zone" + this.countPP
}, {
name: "zone" + this.countPP
}];
} else {
data = [];
}
resolve(data);
}, 500);
}
}};
< / script >