I'm using slight modification from this answer to make header rows collapsible in an HTML table.
I want to modify the JS snippet so that rows are collapsed rather than expanded by default (on page load/document ready). How can I do this?
Basically what I'm trying to achieve is for:
$(this).find('span').text(function(_, value){return value=='-'?'+':'-'});
$(this).nextUntil('tr.header').slideToggle(100, function(){
to be run once at page load/refresh, in addition to when header rows are clicked and toggled.
I know that I'll need to change the two tags two <span>+</span> in HTML, but am stuck on how to trigger this behavior on page load.
Javascript:
$(document).ready(function(){
    $('tr.header').click(function(){
        $(this).find('span').text(function(_, value){return value=='-'?'+':'-'});
        $(this).nextUntil('tr.header').slideToggle(100, function(){
        });
    });
});
HTML:
<table border="0">
  <tr  class="header">
      <th colspan="2">Header <span>-</span></th>
  </tr>
  <tr>
    <td>data</td>
    <td>data</td>
  </tr>
  <tr>
    <td>data</td>
    <td>data</td>
  </tr>
  <tr  class="header">
    <th colspan="2">Header <span>-</span></th>
  </tr>
  <tr>
    <td>date</td>
    <td>data</td>
  </tr>
  <tr>
    <td>data</td>
    <td>data</td>
  </tr>
  <tr>
    <td>data</td>
    <td>data</td>
  </tr>
</table>
CSS:
table, tr, td, th
{
    border: 1px solid black;
    border-collapse:collapse;
}
tr.header
{
    cursor:pointer;
}
JSFiddle: https://jsfiddle.net/mkb39x0u/
 
     
    