title: array within an array in Vuejs
body: <p>I have a data set which one of the values is another array and I am looping through the parents but when I get to the element that has another array I can't seem to get it to display.  Here is relevant parts of my code.</p>
  
  <p>I am looping through my columns as I am creating a table and I have a sorting function on the columns.  Ideally I wouldn't want sorting on the elements column.  I am getting things to output fine except for the columns which is where it is an array of items and not just a value.  I want to go use a v-for on those elements so I can format that how I need.  Tablefilter is a computed property that just sorts the data by filename.</p>
  
  <pre><code>&lt;table id="assets"&gt;
          &lt;thead&gt;
          &lt;tr&gt;
              &lt;th v-for="(head, key) in columns" v-on:click="sort(key)" v-bind:class="{active: sortkey == key}" nowrap&gt;
                  ${head['displayname']}
                  &lt;span v-bind:class="['arrow', sortorders[key] &gt; 0 ? 'asc' : 'dsc']"&gt;&lt;/span&gt;
              &lt;/th&gt;
          &lt;/tr&gt;
          &lt;/thead&gt;
          &lt;tbody&gt;
          &lt;tr v-for="item in tableFilter"&gt;
              &lt;td v-for="(head, key) in columns"&gt;
                  &lt;span v-if="head.displayname != 'Elements'"&gt;${item[key]}&lt;/span&gt;
                  &lt;span v-else&gt;
  
  
                      //This is where I need help
                      &lt;br v-for="element in item[key]"&gt;
                          ${element}
                      &lt;/br&gt;
  
  
                  &lt;/span&gt;
              &lt;/td&gt;
          &lt;/tr&gt;
          &lt;/tbody&gt;
      &lt;/table&gt;
  </code></pre>
  
  <p>Here is my data section.  I left out my computed and methods as it shouldn't affect my issue. </p>
  
  <pre><code>var vm = new Vue({
          el: '#assets',
      delimiters: ['${', '}'],
      data: {
          sections: [
              {
                  id: 1378,
                  filename: 'test.DOC',
                  kind: 'word',
                  size: '18182',
                  elements: [
                      {
                          elementId: 1393,
                          title: 'Test title',
                          mls: 'November 2016: abc123',
                          owner: 'John Doe',
                          expires: '2017-11-01 05:00:00'
                      },
                  ]
              },
              {
                  id: 1383,
                  filename: 'test.pdf',
                  kind: 'pdf',
                  size: '934406',
                  elements: [
                      {
                          elementId: 1389,
                          title: 'test title 2',
                          mls: 'July 2017; 123',
                          owner: 'Jane Doe',
                          expires: '2018-07-01 05:00:00'
                      }, {
                          elementId: 1390,
                          title: 'test title 3',
                          mls: 'July 2018; 456',
                          owner: 'Jack Doe',
                          expires: '2018-07-01 06:00:00'
                      }
                  ]
              }
          ]
      },
              columns: {
                  id : {
                      displayname : "Id"
                  },
                  filename : {
                      displayname : "File Name"
                  },
                  kind : {
                      displayname : "Kind"
                  },
                  size : {
                      displayname: "Size"
                  },
                  elements : {
                      displayname: "Elements"
                  }
              },
  })
  </code></pre>
  
  <p>--- UPDATE ---
  If I put in the following code it will display all of the elements.</p>
  
  <pre><code>&lt;br v-for="elem in item[key]"&gt;
                          ${item[key]}
                      &lt;/br&gt;
  </code></pre>
  
  <p>But if I try to output elem it will give an error that elem is not declared.</p>
  
  <pre><code>&lt;br v-for="elem in item[key]"&gt;
                          ${elem}
                      &lt;/br&gt;
  </code></pre>