Vue.js limit selected checkboxes to 5

问题

I need to limit number of selected checkboxes to 5. I tried using :disabled like here:

    <ul>
        <li v-for="item in providers">
            <input type="checkbox" 
               value="{{item.id}}" 
               id="{{item.id}}" 
               v-model="selected_providers" 
               :disabled="limit_reached" 
            >
        </li>
    </ul>

And then:

new Vue({
    el: '#app',
    computed:{
        limit_reached: function(){
            if(this.selected_providers.length > 5){
                return true;
            }
            return false;
        }
    }
})

This kind of works, but when it reaches 5, all of the check boxes are disabled and you can't uncheck the ones you don't want.

I also tried to splice the array with timeout of 1 ms, which works but feels hacky. Can anyone recommend anything please?

回答1:

Basically, you'd only disable the input if it's not already selected and there's more than 4 of them selected.

The cleanest way I could come up with was:

new Vue({
  el: '#app',
  data: {
    inputs: []
  }
})

With:

<ul>
  <li v-for="n in 10">
    <label>
      <input
        type="checkbox"
        v-model="inputs"
        :value="n"
        :disabled="inputs.length > 4 && inputs.indexOf(n) === -1" 
        number> Item {{ n }} {{ inputs.indexOf(n) }}
    </label>
  </li>
</ul>

Here's a quick demo: https://jsfiddle.net/crswll/axemcp8d/1/

来源：https://stackoverflow.com/questions/35142744/vue-js-limit-selected-checkboxes-to-5