javascript - Polymer change pseudo element with js -

i have following code paper-dropdown-menu polymer. have somehow change content of pseudo-element each item of array, sofar have not been able find out how.

in below code, says content:"{{item.code}}", of course not correct way of doing needs changed every possible value of code in array.

<dom-module id="language-drop"> <style  is="custom-style">  paper-item.lang:after{   content:"{{item.code}}";   color: var(--secondary-text-color);   @apply(--paper-font-caption);   position:absolute;   right:20px; }  </style> <template>     <paper-dropdown-menu label="other">       <paper-listbox class="dropdown-content">         <template is="dom-repeat" items="{{languagechoice}}">             <paper-item class="lang">{{item.author}}</paper-item>         </template>       </paper-listbox>     </paper-dropdown-menu-light> </template>  <script>     polymer({         is: 'language-drop',          properties: {             languagechoice: array         }     }); </script> </dom-module>