如何将数据发送到另一个页面，而无需激发当前页面的PHP

so I am having a page where there is an input field. I want this to work like a CMS system. Let's say that there are options. What I am working on now is one where you can specify how long the summery will be for the content. So I want the input to be saved and sent to the function file where I can use that information in a function. I don't want to be sent to this function file site. Similar to how you can save options in wordpress, but you stay on the same page. I imagine that I perhaps have to use AJAX.

Any help on how I can do this?

If you would like to use some JavaScript here, then localStorage could be of great help to you.

Suppose you have following html form:

<input id = "foo" type = "text">

Write this JavaScript to store the value:

var val = foo.value;
localStorage.setItem(formV,val);

And the following to retireve it:

val = localStorage.getItem(formV);

You can then make an AJAX request to transfer the data to a PHP file:

request = $.ajax({
        type: 'POST',
        url: 'form.php',
        data: { text1: val}});

        request.done( function(response) {

    alert("cool!");
        })

On form.php side:

$val = $_POST['text1'];
 echo $val;

You can learn more about localStorage here and many other places.