Adding Categorizing Functionality to Navigation Widget

#index.py
from flask import render_template
from flask_classful import FlaskView, route
from models.postdb import Postdb
  
class Index(FlaskView):
  
  @route('/')
  def index(self):
    self.postdb = Postdb()
    vdict = self.postdb.get_post()
    return render_template('index.html', data=vdict)

  @route('/post/<id>/')
  def get_single_post(self, id):
    self.postdb = Postdb()
    vdict = self.postdb.get_post(id)
    return render_template('post.html', data=vdict)

  @route('/category/<cat>/')
  def get_post_category(self, cat):
    self.postdb = Postdb()
    vdict = self.postdb.get_post(cat=cat)
    return render_template('index.html', data=vdict)

#models/post.py
import config, copy, lib, requests
from flask import render_template
from flask_classful import FlaskView, route

class Postdb():

  def get_post(self, id='', cat=''):
    vdict = copy.deepcopy(config.vdict)

    if id:
      URL = "https://www.googleapis.com/blogger/v3/blogs/"+vdict['blog-id']+"/posts/"+id
      PARAMS = {"key":vdict['api-key']}
      r = requests.get(url = URL, params = PARAMS)
      data = r.json() 
      vdict['post'] = data
      vdict['id'] = id
    elif cat:
      vdict['cat'] = cat
    
    self.vlib = lib.Lib()
    vdict['date'] = self.vlib.set_date()
    
    return vdict

<!--templates/index.html-->
{% extends "base.html" %}

{% block head %}
{{ super() }}
<script src="/static/scripts/index.js"></script>
<link href="/static/styles/index.css" rel="stylesheet">
{% endblock %}

{% block panel %}
{% if 'cat' in data %}
<script>
  index.label = '{{ data["cat"] }}';
</script>
{% endif %}
<div id="panel" class="panel region"></div>
<div class="navigation region">
  <img onclick="index.navPrevious()" src="/static/images/left.png" /> 
  <img id="nav-home" onclick="index.navHome()" src="/static/images/home.png" /> 
  <img onclick="index.navNext()" src="/static/images/right.png" />
</div>
{% endblock %}

{% block ad %}
<div class="ad region">
  <img src="/static/images/ad.jpg" />
</div>
<div style="clear: both;"></div>
{% endblock %}

{% block content %}
<div id='content'>
  <div id="channel">
    <div id="screen">
      <div id='kvid-screen' width="100%"></div>
    </div>
    <div id="kdownloadButton"></div>
    <div id="kplaylistPanel"></div>
    <div id="next-page">
      <a class="new-vid" onclick="index.previousPageKD()">&lt;&lt; ៥០​ កំរង​វីដេអូ</a>  
      <a class="new-vid" onclick="index.home()">កំរង​វីដេអូ​ដើម</a>
      <a class="new-vid" onclick="index.nextPageKD()"> កំរង​វីដេអូ ៥០ &gt;&gt;</a>
    </div>
  </div>
</div>
{%  endblock %}

GitHub: "https://github.com/Sokhavuth/newspaper
Heroku: https://khmerweb-newspaper.herokuapp.com/