How to use index variable generated from v-for from prent tag in child-tag's v-for value-CodePudding

  <tr v-for='(dialog, dialogIdx) in this.$store.state.dialogSearch.content_keys '>
          <td rowspan='11'>
              <router-link to='' tag='button' class='btn-round'> {{dialog}} d</router-link>
          </td>
          <tr v-for='(content, ContentIdx) in this.$store.state.dialogSearch.contents[dialogIdx]'>
          </tr>
  </tr>

I want take variable dialogIdx that is generated from parent tag's v-for and use the dialogIdx in child tag's v-for value.
I've tried

<tr v-for=`(content, ContentIdx) in this.$store.state.dialogSearch.contents[${dialogIdx}]`

<tr v-for="(content, ContentIdx) in this.$store.state.dialogSearch.contents[{{dialogIdx}}]"

CodePudding user response：

It's only because you used this keyword for the nested v-for directive. this refers to the function context that invoked the code execution, which in your case will be the parent v-for directive. Try removing the this keyword from the second v-for loop. You can map the this.$store.state["dialogSearch/contents"] to a computed property and then use it within the nested v-for loop without the this keyword.

Sample implementation

Vue.config.productionTip = false
Vue.config.devtools = false

new Vue({
  el: "#app",
  data: function() {
    return {
      content_keys: {
        0: 'Label 1',
        1: 'Label 2',
        2: 'Label 3',
        3: 'Label 4',
      },
      child_keys: {
        0: {
          0: 'Label 1 Child 1',
          1: 'Label 1 Child 2',
          2: 'Label 1 Child 3',
          3: 'Label 1 Child 4'
        },
        1: {
          0: 'Label 2 Child 1',
          1: 'Label 2 Child 2',
          2: 'Label 2 Child 3',
          3: 'Label 2 Child 4'
        },
        2: {
          0: 'Label 3 Child 1',
          1: 'Label 3 Child 2',
          2: 'Label 3 Child 3',
          3: 'Label 3 Child 4'
        },
        3: {
          0: 'Label 4 Child 1',
          1: 'Label 4 Child 2',
          2: 'Label 4 Child 3',
          3: 'Label 4 Child 4'
        },
      },
    };
  }
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id=app>
  <table border="1">
    <tr v-for="(dialog, dialogIdx) in this.content_keys">
      <td>{{ dialog }}</td>
      <td v-for="(content, contentIdx) of child_keys[dialogIdx]">
        {{ dialogIdx }} : {{ content }}</td>
    </tr>
  </table>
</div>

CodePudding user response：

Check an optimized unique approach using reusable computed property

computed: {
   getContent() {
       return contextObj => {
        if(contextObj.label ==='content_keys') return this.$store.state.dialogSearch.content_keys;
        else return this.$store.state.dialogSearch.contents[contextObj.key];
      }
    }
}

and the changes in your template should be

 <tr v-for="(dialog, dialogIdx) in getContent({label: 'content_keys})">
          <td rowspan='11'>
              <router-link to='' tag='button' class='btn-round'> {{dialog}} d</router-link>
          </td>
          <tr v-for="(content, ContentIdx) in getContent({label: 'content_index', key: dialogIdx})">
          </tr>
  </tr>