PHP plugin that takes raw text from a POST request and returns the processed text?

@FedorovDeomid, Not sure what the origin of the API request is, but here is a simple sample.

• Install fresh copy of Grav 1.7.33

• In file /user/pages/02.typography/default.md add the following script somewhere:

  JSCopy

  <script>
  "use strict";
  class Sender {
  
  async send() {
    let response;
  
    try {
      response = await fetch(window.location.pathname + '/myapi:mytask', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({formField: 'Hello world!'}),
      });
    }
    catch (error) {
      alert('Error');
      return;
    }
  
    if (response.ok) {
      const answer = await response.json();
      alert(answer.formField);
    }
    else {
      alert('Invalid answer');
    }
  }
  }
  
  const sender = new Sender();
  void sender.send();
  </script>
  

• Install plugin DevTools $ bin/gpm install devtools
• Create new plugin $ bin/plugin devtools new-plugin

• At the last line in function onPluginsInitialized in file /user/plugins/yourplugin/yourplugin.php add the following:

  PHPCopy

  // Should use $this->grav['uri'] object and check if API request is made 
  // on correct route
  $isCorrectRoute = true;
  
  if ($isCorrectRoute) {
  // Use Uri again to get params of API request.
  
  $asyncPostData = json_decode(file_get_contents('php://input'), true);
  
  if ($asyncPostData) {
    $asyncPostData['formField'] = strtoupper($asyncPostData['formField']);
    echo json_encode($asyncPostData);
  
    die();
  }
  }
  

• When accessing page https://yourdomain/typography you should get an alert with 'HELLO WORLD!'.

Note:

• This is only a rough concept to get you going.
• I presume, you know to use JavaScript to write the response back into the form field.
• Please check if correct route is being called. You don't want to run the plugin on each and every request.
• Use the params of the request to determine which function to execute.
• See the docs about plugins