function highlight_otp()

in resources/web/docs_js/index-v1.js [223:257]

• 28 lines of code
• 5 McCabe index (conditional complexity)

function highlight_otp() {
  let visibleHeadings = []
  const observer = new IntersectionObserver(entries => {
    entries.forEach(entry => {
      const id = entry.target.getAttribute('id');
      const element = document.querySelector(`#sticky_content #this_page a[href="#${id}"]`);
      const itemId = $(element).parent().attr('id')
      // All heading elements have an `entry` (even the title).
      // The title does not exist in the OTP, so we must exclude it.
      // Checking for the existence of `itemId` ensures we don't parse elements that don't exist.
      if (itemId){
        const itemNumber = parseInt(itemId.match(/\d+/)[0], 10);
        if (entry.intersectionRatio > 0){
          visibleHeadings.push(itemNumber);
        } else {
          const position = visibleHeadings.indexOf(itemNumber);
          visibleHeadings.splice(position, 1)
        }
        if (visibleHeadings.length > 0) {
          visibleHeadings.sort((a, b) => a - b)
          // Remove existing active classes
          $('a.active').removeClass("active");
          // Add active class to the first visible heading
          $('#otp-text-' + visibleHeadings[0] + ' > a').addClass('active')
        }
      }
    })
  })

  document.querySelectorAll('div#content a[id]').forEach((heading, i) => {
    // Skip the first heading since it's not visible
    if (i === 0) return
    observer.observe(heading);
  })
}