src/components/bootue/alert/template.html
<transition name="fade">
<div v-show="val" :class="['alert', 'alert-'+type, placement]" :style="{width:width}" role="alert">
<button v-show="dismissable" type="button" class="close" @click="val = false">
<span>×</span>
</button>
<slot></slot>
</div>
</transition>