Czy istnieje sposób, w jaki mogę uruchomić funkcję php za pomocą funkcji JS?

coś takiego:

<script type="text/javascript">
function test(){
document.getElementById("php_code").innerHTML="<?php 
query("hello");       ?>";    
}
</script>

<a href="#" style="display:block; color:#000033; font-family:Tahoma; font-size:12px;"     
onclick="test(); return false;"> test </a>
<span id="php_code"> </span>

Zasadniczo chcę uruchomić funkcję php query("hello"), kiedy klikam href o nazwie „Test”, który wywoła funkcję php.

To jest w istocie, co AJAX jest za . Twoja strona ładuje się i dodajesz zdarzenie do elementu. Kiedy użytkownik wywołuje zdarzenie, powiedzmy, klikając coś, Twój JavaScript używa obiektu XMLHttpRequest do wysłania żądania do serwera.

Gdy serwer odpowie (prawdopodobnie z wyjściem), inna funkcja / zdarzenie Javascript daje ci miejsce do pracy z tym wyjściem, w tym po prostu umieszczając go na stronie, jak każdy inny element HTML.

Możesz to zrobić „ręcznie” za pomocą zwykłego JavaScript lub możesz użyć jQuery. W zależności od wielkości projektu i konkretnej sytuacji, prostsze może być użycie zwykłego JavaScript.

Zwykły JavaScript

W tym bardzo podstawowym przykładzie wysyłamy żądanie, myAjax.phpgdy użytkownik kliknie łącze. Serwer wygeneruje treść, w tym przypadku „hello world!”. Umieścimy w elemencie HTML z id output.

Plik javascript

// handles the click event for link 1, sends the query
function getOutput() {
  getRequest(
      'myAjax.php', // URL for the PHP file
       drawOutput,  // handle successful request
       drawError    // handle error
  );
  return false;
}  
// handles drawing an error message
function drawError() {
    var container = document.getElementById('output');
    container.innerHTML = 'Bummer: there was an error!';
}
// handles the response, adds the html
function drawOutput(responseText) {
    var container = document.getElementById('output');
    container.innerHTML = responseText;
}
// helper function for cross-browser request object
function getRequest(url, success, error) {
    var req = false;
    try{
        // most browsers
        req = new XMLHttpRequest();
    } catch (e){
        // IE
        try{
            req = new ActiveXObject("Msxml2.XMLHTTP");
        } catch(e) {
            // try an older version
            try{
                req = new ActiveXObject("Microsoft.XMLHTTP");
            } catch(e) {
                return false;
            }
        }
    }
    if (!req) return false;
    if (typeof success != 'function') success = function () {};
    if (typeof error!= 'function') error = function () {};
    req.onreadystatechange = function(){
        if(req.readyState == 4) {
            return req.status === 200 ? 
                success(req.responseText) : error(req.status);
        }
    }
    req.open("GET", url, true);
    req.send(null);
    return req;
}

The HTML

<a href="#" onclick="return getOutput();"> test </a>
<div id="output">waiting for action</div>

The PHP

// file myAjax.php
<?php
  echo 'hello world!';
?>

Try it out: http://jsfiddle.net/GRMule/m8CTk/

With a javascript library (jQuery et al)

Arguably, that is a lot of Javascript code. You can shorten that up by tightening the blocks or using more terse logic operators, of course, but there's still a lot going on there. If you plan on doing a lot of this type of thing on your project, you might be better off with a javascript library.

Using the same HTML and PHP from above, this is your entire script (with jQuery included on the page). I've tightened up the code a little to be more consistent with jQuery's general style, but you get the idea:

// handles the click event, sends the query
function getOutput() {
   $.ajax({
      url:'myAjax.php',
      complete: function (response) {
          $('#output').html(response.responseText);
      },
      error: function () {
          $('#output').html('Bummer: there was an error!');
      }
  });
  return false;
}

Try it out: http://jsfiddle.net/GRMule/WQXXT/

Don't rush out for jQuery just yet: adding any library is still adding hundreds or thousands of lines of code to your project just as surely as if you had written them. Inside the jQuery library file, you'll find similar code to that in the first example, plus a whole lot more. That may be a good thing, it may not. Plan, and consider your project's current size and future possibility for expansion and the target environment or platform.

If this is all you need to do, write the plain javascript once and you're done.

Documentation

• AJAX on MDN - https://developer.mozilla.org/en/ajax
• XMLHttpRequest on MDN - https://developer.mozilla.org/en/XMLHttpRequest
• XMLHttpRequest on MSDN - http://msdn.microsoft.com/en-us/library/ie/ms535874%28v=vs.85%29.aspx
• jQuery - http://jquery.com/download/
• jQuery.ajax - http://api.jquery.com/jQuery.ajax/

PHP is evaluated at the server; javascript is evaluated at the client/browser, thus you can't call a PHP function from javascript directly. But you can issue an HTTP request to the server that will activate a PHP function, with AJAX.

The only way to execute PHP from JS is AJAX. You can send data to server (for eg, GET /ajax.php?do=someFunction) then in ajax.php you write:

function someFunction() {
    echo 'Answer';
}

if ($_GET['do'] === "someFunction") {
    someFunction();
}

and then, catch the answer with JS (i'm using jQuery for making AJAX requests)

Probably you'll need some format of answer. See JSON or XML, but JSON is easy to use with JavaScript. In PHP you can use function json_encode($array); which gets array as argument.

I recently published a jQuery plugin which allows you to make PHP function calls in various ways: https://github.com/Xaxis/jquery.php

Simple example usage:

// Both .end() and .data() return data to variables
var strLenA = P.strlen('some string').end();
var strLenB = P.strlen('another string').end();
var totalStrLen = strLenA + strLenB;
console.log( totalStrLen ); // 25

// .data Returns data in an array
var data1 = P.crypt("Some Crypt String").data();
console.log( data1 ); // ["$1$Tk1b01rk$shTKSqDslatUSRV3WdlnI/"]