title: Secure way to handle frontend login
body: <p>A few questions came across my mind about how to secure a login page (Web). </p>
  
  <p>When I build a demo app for instance a web-application with VueJS or just really blank using HTML/JS, I thought can a login page be ever secure? Or am I missing something. </p>
  
  <p>For example: 
  When I create the login page where a user can click on a login button I potentially send a request to my backend server and if it is successful an access-token is returned and then I route my frontend page to the next view or create some object, unnecessary. </p>
  
  <p>Now to the question: 
  Is there a way to present a new view if the login really worked? Because I can just look in the Javascript file change the response or either fill in my own response and the behaviour is displayed what should only be displayed when the login was successful. </p>
  
  <p>Am I forced to PHP to do so, or is there the same result? Am I missing something?
  Thanks for your answers!
  I hope you understand what I mean.  </p>