use this code:

<div id="vueapp">
  <textarea v-model="jsonstr" rows="8" cols="40"></textarea>
  <pre>{{ jsonstr | pretty }}</pre>
</div>

and JS:

new Vue({
  el: '#vueapp',
  data: {
    jsonstr: '{"id":1,"name":"A green door","price":12.50,"tags":["home","green"]}'
  },
  filters: {
    pretty: function(value) {
      return JSON.stringify(JSON.parse(value), null, 2);
    }
  }
})

There are two imporatnt fixes required in this code:

1. Since there is no id in data you should use city name instead as it is unique
2. Also, you should use the (value, key) in object approach for your problem.

An example of this code can be:

<div id="app">
  <ul>
    <li v-for="(cityData, city) in districtData" :key="city">
      {{city}} - {{cityData.lastupdatedtime}}
    </li>
  </ul>
</div> 

you can also use this pen for testing: https://codepen.io/abdullah-shabaz/pen/MWwZQYo

The response that you are getting back is an array containing another array - which in turn contains the actual objects representing your tracks.

So inside: <li v-for="track in tracks">@{{ track.name }}</li> , the track refers to the inside array and not to each object.

For quick-fix, you can change your code to: <li v-for="track in tracks[0]">@{{ track.name }}</li> and try.

But the proper fix would be to fix the backend, to return the result as a single array of objects.

use this code:

<div id="vueapp">
  <textarea v-model="jsonstr" rows="8" cols="40"></textarea>
  <pre>{{ jsonstr | pretty }}</pre>
</div>

and JS:

new Vue({
  el: '#vueapp',
  data: {
    jsonstr: '{"id":1,"name":"A green door","price":12.50,"tags":["home","green"]}'
  },
  filters: {
    pretty: function(value) {
      return JSON.stringify(JSON.parse(value), null, 2);
    }
  }
})

You can add a filter to stringify the data in a nicer format.

filters: {
  pretty: (val, indent = 2) => {
    if (typeof val !== "object") {
      try {
        val = JSON.parse(val)
      } catch (err) {
        console.warn("value is not JSON")
        return val
      }
     
      return JSON.stringify(val, null, indent)
    }
  }
}

Use CSS white-space or simply use a <pre> tag to keep formatting in your template

<pre>{{ entrie.response.content.text | pretty(4) }}</pre>

Demo ~ https://jsfiddle.net/ktz49q1h/

Note that filters are not supported in Vue3. See the migration strategy for solutions.

Set a guard to prevent render before items are fetched:

<template>
  <section v-if="filmDetails && filmDetails.length">
    <div v-for="item in filmDetails">
      <p>{{item.summary}}</p>
    </div>
  </section>
</template>