function setSelected (el, binding, vm) {
const value = binding.value
const isMultiple = el.multiple
if (isMultiple && !Array.isArray(value)) {
process.env.NODE_ENV !== 'production' && warn(
`<select multiple v-model="${binding.expression}"> ` +
`expects an Array value for its binding, but got ${
Object.prototype.toString.call(value).slice(8, -1)
}`,
vm
)
return
}
let selected, option
for (let i = 0, l = el.options.length; i < l; i++) {
option = el.options[i]
if (isMultiple) {
selected = looseIndexOf(value, getValue(option)) > -1
if (option.selected !== selected) {
option.selected = selected
}
} else {
if (looseEqual(getValue(option), value)) {
if (el.selectedIndex !== i) {
el.selectedIndex = i
}
return
}
}
}
if (!isMultiple) {
el.selectedIndex = -1
}
}
// 实际的选项
function actuallySetSelected (el, binding, vm) {
// 绑定的值和是否多选
const value = binding.value
const isMultiple = el.multiple
if (isMultiple && !Array.isArray(value)) { // 值不是数组而且是多选,肯定出错啦
process.env.NODE_ENV !== 'production' && warn(
`<select multiple v-model="${binding.expression}"> ` +
`expects an Array value for its binding, but got ${
Object.prototype.toString.call(value).slice(8, -1)
}`,
vm
)
return
}
let selected, option
// 对选项进行遍历 改变其值
for (let i = 0, l = el.options.length; i < l; i++) {
option = el.options[i]
if (isMultiple) {
// 检查形态拿到index
selected = looseIndexOf(value, getValue(option)) > -1
if (option.selected !== selected) {
option.selected = selected
}
} else {
// 直接检查形态就行
if (looseEqual(getValue(option), value)) {
if (el.selectedIndex !== i) {
el.selectedIndex = i
}
return
}
}
}
if (!isMultiple) {
el.selectedIndex = -1 //选不到了
}
}