为了让它与指令一起工作，我们需要了解v-model是如何工作的.从docs人中:
<input v-model="something">
只是语法糖:
<input v-bind:value="something" v-on:input="something = $event.target.value">
对于select元素，v-model将监听change事件(而不是input).因此，如果指令在元素更改时发送change事件，那么v-model将按预期工作.
以下是代码的更新版本(适用于Vue 2):
Vue.directive('select', {
twoWay: true,
bind: function (el, binding, vnode) {
$(el).select2().on("select2:select", (e) => {
// v-model looks for
// - an event named "change"
// - a value with property path "$event.target.value"
el.dispatchEvent(new Event('change', { target: e.target }));
});
},
componentUpdated: function(el, me) {
// update the selection if the value is changed externally
$(el).trigger("change");
}
});
var app = new Vue({
el: '#app',
data: {
supplier_id: "niklesh"
},
})
$('#supplier_id').select2({});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.1.4/vue.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.5/css/bootstrap.css">
<div id="app">
{{ supplier_id }}
<select id="supplier_id" class='form-control' v-model='supplier_id' v-select='supplier_id'>
<option value="atul">Atul</option>
<option value="niklesh">Niklesh</option>
<option value="sachin">Sachin</option>
</select>
</div>
下面是一个在Vue 3中工作的版本(自定义指令有不同的语法，linked here):
var app = Vue.createApp({
data: function() {
return {
supplier_id: "niklesh"
}
}
})
app.directive('select', {
beforeMount: function (el, binding, vnode) {
$(el).select2().on("select2:select", (e) => {
// v-model looks for
// - an event named "change"
// - a value with property path "$event.target.value"
el.dispatchEvent(new Event('change', { target: e.target }));
});
},
updated: function(el) {
// update the selection if the value is changed externally
$(el).trigger("change");
}
});
app.mount('#app');
$('#supplier_id').select2({});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.js"></script>
<script src="https://unpkg.com/vue@3.0.11"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.5/css/bootstrap.css">
<div id="app">
{{ supplier_id }}
<select id="supplier_id" class='form-control' v-model='supplier_id' v-select='supplier_id'>
<option value="atul">Atul</option>
<option value="niklesh">Niklesh</option>
<option value="sachin">Sachin</option>
</select>
</div>