Is it possible to run a Javascript function in PHP?

Question

I want to run a function of JavaScript without "submitting" it, or when the screen is accessed the php will call the function JavaScript and run what’s in it and then continue the normal code. It’s possible? Obs: The function contains data that only rotate in the JavaScript!

My goal is to run this stretch:

<script language="javascript" type="text/javascript">
    for(i = 0; i < 10; i++){
        if(objp!=''){           
            n_p[i] = 'P' + objp[0];
            objp.splice(0,1);
        }
        else{
            n_p[i] = 'S' + objs[0];
            objs.splice(0,1);
        }   
    }
</script>
//No PHP

For a better understanding of the above section follow Here

Answer 1

PHP does not know Javascript

PHP cannot directly call a Javascript function because PHP is interpreted on the server side.

PHP does not see a code there, it simply copies the text character by character and sends it to the user’s browser.

The browser knows Javascript

When the browser reads the received data already in HTML, it starts to interpret this HTML and assemble the elements on the screen.

When finding a tag <script> nevegador stops what it is doing and executes what it has in this script.

Note that at this point, the browser is running the script on the user’s computer, while PHP (which has possibly finished running) was running on the server.

Execute code on page loading

Then, for all purpose, the code quoted in the question will run in the browser exactly at the time the browser receives it from the server. No explicit call is required.

<script language="javascript" type="text/javascript">
    //todo código aqui será executado
</script>

Performing functions

However, if you have a declared function, the snippet is interpreted and the function is created, but it is not automatically invoked:

<script language="javascript" type="text/javascript">
    function f_mostra() {
        alert("Entrei");
    }
</script>

However, just add a later call to the function declaration to run it:

<script language="javascript" type="text/javascript">
    function f_mostra() {
        alert("Entrei");
    }
    f_mostra();
</script>

Or else:

<script language="javascript" type="text/javascript">
    function f_mostra() {
        alert("Entrei");
    }
</script>
<!-- ... -->
<script language="javascript" type="text/javascript">
    f_mostra();
</script>

Waiting for the page to be ready

The problem is that it is not always desirable to run Javascript while the page is being loaded, after all the browser may not have finished assembling all the HTML.

It is then possible to capture the event that says if the page is fully loaded:

window.onload = function() {
  //executado quando tudo na página está carregado
};

Everything I said above is not exactly true ;)

There are techniques and technologies that actually make it possible for PHP (or any other language) to perform a Javascript function when the user has an open page, without a new request.

Today with HTML 5, we have the technology Websockets which enables persistent communication between client (Javascript) and server (PHP). However, I will not go into detail as it is a more complex subject.

Answer 2

It’s very simple, just call the Javascript function by echo in PHP.

echo '<script>funcaophp();</script>'