扁平数据树形化

扁平数据树形化

`transformTree(list, options = {}) {
const {
keyField = 'id',
childField = 'children',
parentField = 'parentid'
} = options

const tree = []
const record = {}

for (let i = 0, len = list.length; i < len; i++) {
const item = list[i]
const id = item[keyField]

if (!id) {
continue
}

if (record[id]) {
item[childField] = record[id]
} else {
item[childField] = record[id] = []
}

if (item[parentField]) {
const parentId = item[parentField]

if (!record[parentId]) {
record[parentId] = []
}

record[parentId].push(item)
} else {
tree.push(item)
}
}
return tree
}`