Canvas LMS: Add a button to the sidebar to trigger RTE LTI Launch

custom.js

$(function(){
  var $body = $('body');
  // Add a button to launch the Outline Builder, which triggers the RTE LTI Launch
  if($body.hasClass('syllabus')) {
    // #editor_tabs is only visible when the RTE is active
    $('#editor_tabs').prepend('<div style="padding-bottom:1em;"><a class="Button Button--primary icon-compose" id="launch_outline_editor_button">Course Outline Builder</a></div>');
    
    $('#launch_outline_editor_button').click(function(){
      // Existing RTE LTI buttons are added with aria-label set to the "Name" of the tool, as defined in the tool settings UI, not the XML
      $('div[aria-label="Outline Builder"]').click();
    });
  }
});