title: Using jQuery to call PHP function
body: <p>I've been doing some research on calling a PHP function within a file from jQuery and can't seem to find a proper way of doing this without it failing on me. I'm trying to create an intermediary (kind of) CMS with MVVM to create a single-page website with a WordPress base. </p>
  
  <p>At the moment I'm stuck on a bit where I'm trying to access PHP functions in allocated files, I've seen examples <a href="https://stackoverflow.com/questions/14600989/ajax-in-wordpress-not-calling-php-function">here</a>, <a href="https://stackoverflow.com/questions/8487172/wordpress-jquery-how-to-call-a-wordpress-function-with-jquery-on-click-event">here</a> and <a href="https://stackoverflow.com/questions/15757750/php-function-call-using-javascript/15757864#15757864">here</a> on how to do it with a function per file, but I'd like to be able to call a function in a file as it gives me a clearer overview. </p>
  
  <p>I've checked the link and it's correct, the PHP file is called <code>posts.php</code> and its in the location defined by <code>window.MODELS</code>, however the function <code>fetch_all</code> doesn't get executed. </p>
  
  <p>JavaScript</p>
  
  <pre><code>//call php function
  var requestURL = window.MODELS + 'posts/fetch_all';
  
  $.get(requestURL, function(data){
      console.log('checking data: ', data);
  }, 'json')
      .done(function(passed){
          console.log('it worked!');
      })
      .fail(function(failed){
          console.log('it failed :( ');
      });
  </code></pre>
  
  <p>PHP</p>
  
  <pre><code>public function fetch_all(){
      return json_encode("this is fetch_all..."); //replace text to get all posts with get_posts()
  }  
  </code></pre>
  
  <p>The console shows the JavaScript fail: "it failed :( ". How do I get 'fetch_all' to be executed and return data?</p>