title: Filter based on checkbox clicked
body: <p>I want to filter the product based on user clicked checkbox. I want to append the checkbox value and show it in URL and filter products based on those value in URL. I used <code>onChange="this.form.submit()"</code> but everytime i check the checkbox it replaces old value with new in URL. How to append all these values and filter based on those values.</p>
  
  <pre><code>&lt;form action="{{route('filter')}}" method="GET"
  &gt;  
  
  &lt;div class="container"&gt;
      &lt;div class="row"&gt;
  
  
           &lt;div class="col-md-4"&gt;
              Search
          &lt;input type="checkbox" name="category_id['samsung']" class="form-control" value="1" onChange="this.form.submit(){{ request()-&gt;filled('category_id.samsung') ? 'checked' :''}}"&gt;Samsung
  
          &lt;input type="checkbox" name="category_id['android']" class="form-control" value="2"onChange="this.form.submit(){{ request()-&gt;filled('category_id.android') ? 'checked' :''}}" &gt;Android
  
          &lt;input type="checkbox" name="category_id['apple']" class="form-control" value="3" onChange="this.form.submit(){{ request()-&gt;filled('category_id.apple') ? 'checked' :''}}"&gt;Apple
          &lt;/div&gt;
      &lt;/form&gt;
  </code></pre>
  
  <p>my url is browser is:</p>
  
  <pre><code>http://localhost:8000/?category_id%5B%27samsung%27%5D=1
  
  http://localhost:8000/?category_id%5B%27android%27%5D=2
  
  http://localhost:8000/?category_id%5B%27apple%27%5D=3
  </code></pre>
  
  <p>the value is url is updated when i checked another checkbox, actually i need to append it</p>