How to return JavaScript from PHP file through AJAX?

Question

How to do this?

1. We have button with onclick event, that sends a query using AJAX to PHP file.
2. PHP file has this JavaScript: echo '<script>alert("hello");</script>';
3. When pushing onclick event button, JavaScript doesn't work. I don't see a "hello" message.

Does anybody knows how to execute JavaScript from PHP? I need exactly this one. I know that all JavaScript should be executed on the AJAX level. But the situation demands to execute a JavaScript, that PHP returns as response.

Best regards

Answer 1

You cannot execute Javascript from PHP since PHP executes on the server side while JS on the client side. You need to eval the returned Javascript code on the client side.

You can do this in your AJAX callback function:

$('#yourButton').onclick(function(){
    //make your ajax request
    $.ajax({
        url : "url",
        success : function(resp){
            //resp is the javascript code sent back from PHP
            //eval it
            eval(resp);
        }
    })
});