Vue.js: Conditional class styling

问题

I have some data that is accessible via:

{{ content['term_goes_here'] }}

... and this evaluated to either true or false. I'd like to add a class depending on the truthiness of the expression like so:

<i class="fa" v-bind:class="[{{content['cravings']}} ? 'fa-checkbox-marked' : 'fa-checkbox-blank-outline']"></i>

where true gives me the class fa-checkbox-marked and false would give me fa-checkbox-blank-outline. The way I wrote it above gives me an error:

- invalid expression: v-bind:class="[{{content['cravings']}} ? 'fa-checkbox-marked' : 'fa-checkbox-blank-outline']"

How should I write it to be able to conditionally determine the class?

回答1:

Use the object syntax.

v-bind:class="{'fa-checkbox-marked': content['cravings'],  'fa-checkbox-blank-outline': !content['cravings']}"

When the object gets more complicated, extract it into a method.

v-bind:class="getClass()"

methods:{
    getClass(){
        return {
            'fa-checkbox-marked': this.content['cravings'],  
            'fa-checkbox-blank-outline': !this.content['cravings']}
    }
}

Finally, you could make this work for any content property like this.

v-bind:class="getClass('cravings')"

methods:{
  getClass(property){
    return {
      'fa-checkbox-marked': this.content[property],
      'fa-checkbox-blank-outline': !this.content[property]
    }
  }
}

回答2:

<i class="fa" v-bind:class="cravings"></i>

and add in computed :

computed: {
    cravings: function() {
        return this.content['cravings'] ? 'fa-checkbox-marked' : 'fa-checkbox-blank-outline';
    }
}

回答3:

Why not pass an object to v-bind:class to dynamically toggle the class:

<div v-bind:class="{ disabled: order.cancelled_at }"></div>

This is what is recommended by the Vue docs.

回答4:

the problem is blade, try this

<i class="fa" v-bind:class="['{{content['cravings']}}' ? 'fa-checkbox-marked' : 'fa-checkbox-blank-outline']"></i>

来源：https://stackoverflow.com/questions/43210508/vue-js-conditional-class-styling