How to add condition in index.html file in react js

Question

I want to use the google tag manager script just for the signup page. I don't want them for other pages. How can I add a condition in the index.html file in react to get the current URL?

I have already added the code to check if the environment is in production or not. This was the code

<% if (process.env.NODE_ENV === 'production') { %>
  <!-- Meta Pixel Code -->
  <script>
   ...
  </script>
<% } %>

But now to get the URL or pathname when I give the below code I'm getting a "window not defined" error. Do we have a way to get the URL in index.html file for react?

<% if (window.location.pathname === '/signup') { %>

Answer 1

Create a component like this

    export default function TrackingPixels(props) {
  
  useEffect(() => {
    return () => {
      handleRemoveScripts();
    }
  }, []);
    
  useEffect(() => {

    GoogleTagManager(value);

    return () => {
      handleRemoveScripts();
    }
  }, [(props.pagePixel || props.resourceCenterPixel)]);

  const handleRemoveScripts = () => {
    for (let id of elementIds) {
      removeScript(id);
    }
  }

  return null
}

function createScript(id, scriptText, src, async) {
  var script = document.createElement("script")

  if(id) {
    script.setAttribute("id", id)
  }

  if(src) {
    script.setAttribute("src", src);
  }

  if(async) {
    script.async = true;
  }

  if(scriptText) {
    script.appendChild(document.createTextNode(scriptText));
  }

  try {
    document.head.appendChild(script);
  } catch (e) {
    script.text = scriptText;
    document.head.appendChild(script);
  }
}

function noScriptForGTM(id, url) {
  var script = document.createElement("noscript")
  script.setAttribute("id", id)
  var x = document.createElement("iframe");
  x.setAttribute("src", url);
  x.setAttribute("width", "0")
  x.setAttribute("height", "0")
  x.setAttribute("style", "display:none;visibility:hidden")
  script.appendChild(x);

  var body = document.getElementsByTagName("body")[0];
  body.insertBefore(script, body.firstChild);
}

function removeScript(scriptId) {
   var elements = document.querySelectorAll(`#${scriptId}`);
   elements.forEach((element)=> {
    if (element) {
        element.parentNode.removeChild(element);
      }
    })
}

function GoogleTagManager(value) {

  if(!value) {
    return false;
  }

  const id = "google-tag-manager"
  const scriptText = `(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
  new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
  j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
  'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
  })(window,document,'script','dataLayer','${value}');`
  const url = `https://www.googletagmanager.com/ns.html?id=${value}`
  noScriptForGTM(id, url);
  createScript(id, scriptText, null, false);

  return false;
}

And Add it in your signup page.