Vue & conditional rendering with template tag

问题

I am trying to follow documentation:

https://vuejs.org/v2/guide/conditional.html

But for some reason my template is not working as expected, as soon as I put <template v-if="variable"> vue fails to render anything.

<script type="text/x-template" id="dashboard-inititial-message">

<template v-if="okBoom">
    <h1>Title</h1>
    <p>Paragraph 1</p>
    <p>Paragraph 2</p>
</template>

<div v-if="ok">
    <h1>Title</h1>
    <p>Paragraph 1</p>
    <p>Paragraph 2</p>
</div>
<div v-else>
    <p>ELSE</p>
</div>
</script>

Any advice?

Snippets that demonstrate problem:

https://jsfiddle.net/o2tL2ems/1/

回答1:

There is a thing to know about vue.js, Peter pointed it out in a comment. Template cannot be a root element and in general root tag can be only one.

So when you have template like this:

<script type="text/x-template" id="dashboard-inititial-message-mk1">
    <div v-if="okBoom">
        <h1>Title</h1>
        <p>Paragraph 1</p>
        <p>Paragraph 2</p>
    </div>
    <h3>adas</h3>
    <div v-if="ok">
        <h1>Title</h1>
        <p>Paragraph 1</p>
        <p>Paragraph 2</p>
    </div>
</script>

You basically asking vue.js for problems. Vue will stop parsing your template as soon as div with okBoom ends.

There are questions similar to mine all over the internet:

Oddity with templates and root node with vue.js

Solution in short. Wrap your template into master span, div or transition (this one however seems to be a bit hacky, on the other hand it won't generate unnecessary html tags).

回答2:

I use conditional template rendering for loaders (while a server request is taking place)

new Vue({
  el: "#app",
  template:
  `<div v-else class='somePage'>
       <template v-if="isLoading">
         <div>LOADING...</div>
       </template>
       <template v-else>
         <h1>title</h1>
         <p>The final rendered result will not include the "template" element.</p>
       </template>
    </div>`,
  data: () => ({
    isLoading: true
  }),
  mounted() {
    setTimeout(this.getData.bind(this), 1500);
  },
  methods: {
		async getData() {
      // await axios ...do some request...
      this.isLoading = false
    }
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app"></div>

来源：https://stackoverflow.com/questions/42373918/vue-conditional-rendering-with-template-tag

标签

javascript

vuejs2

web-frontend