How to call a JavaScript function from PHP

Question

How to call a JavaScript function from PHP    lt  php    jsfunction         or   echo jsfunction          or      Anything else    The following code is from xyz html  on a button click  it calls a wait   in an external xyz js  This wait   calls wait php   function wait        xmlhttp GetXmlHttpObject      var url  wait php       xmlhttp onreadystatechange statechanged     xmlhttp open  GET   url  true      xmlhttp send null       function statechanged        if xmlhttp readyState  4           document getElementById  txt   innerHTML xmlhttp responseText          and wait php   lt  php echo   lt script gt  loadxml     lt  script gt       where loadxml   calls code from another PHP file the same way    The loadxml   is working fine otherwise  but it is not being called the way I want it

User · Answer

If you want to echo it out for later execution it's ok

If you want to execute the JS and use the results in PHP use V8JS

V8Js::registerExtension('say_hi', 'print("hey from extension! "); var said_hi=true;', array(), true);
$v8 = new V8Js();
$v8->executeString('print("hello from regular code!")', 'test.php');
$v8->executeString('if (said_hi) { print(" extension already said hi"); }');

You can refer here for further reference: What are Extensions in php v8js?

If you want to execute HTML&JS and use the output in PHP http://htmlunit.sourceforge.net/ is your solution

User · Answer

I always just use  echo   lt script gt  function     lt  script gt    or something similar  you re not technically calling the function in PHP  but this as close as your going to get

User · Answer

You can t   You can call a JS function from HTML outputted by PHP  but that s a whole  nother thing

User · Answer

PHP runs in the server  JavaScript runs in the client  So php can t call a JavaScript function

User · Answer

As far as PHP is concerned  or really  a web server in general   an HTML page is nothing more complicated than a big string   All the fancy work you can do with language like PHP - reading from databases and web services and all that - the ultimate end goal is the exact same basic principle  generate a string of HTML    Your big HTML string doesn t become anything more special than that until it s loaded by a web browser  Once a browser loads the page  then all the other magic happens - layout  box model stuff  DOM generation  and many other things  including JavaScript execution   So  you don t  call JavaScript from PHP   you  include a JavaScript function call in your output    There are many ways to do this  but here are a couple   Using just PHP   echo   lt script type  text javascript  gt          jsfunction             lt  script gt       Escaping from php mode to direct output mode    lt  php        some php stuff   gt   lt script type  text javascript  gt      jsFunction     lt  script gt    You don t need to return a function name or anything like that   First of all  stop writing AJAX requests by hand   You re only making it hard on yourself   Get jQuery or one of the other excellent frameworks out there   Secondly  understand that you already are going to be executing javascript code once the response is received from the AJAX call   Here s an example of what I think you re doing with jQuery s AJAX    get       wait php               function returnedData            document getElementById  txt   innerHTML   returnedData               Ok  here s where you can call another function         someOtherFunctionYouWantToCall                But unless you really need to  you don t have to            We re already in the middle of a function execution            right here  so you might as well put your code here             text      function someOtherFunctionYouWantToCall            stuff     Now  if you re dead-set on sending a function name from PHP back to the AJAX call  you can do that too       get       wait php               function returnedData               Assumes returnedData has a javascript function name         window returnedData                 text         Or JSON or XML etc

User · Answer

Thats not possible  PHP is a Server side language and JavaScript client side and they don t really know a lot about each other  You would need a Server sided JavaScript Interpreter  like Aptanas Jaxer   Maybe what you actually want to do is to use an Ajax like Architecture  JavaScript function calls PHP script asynchronously and does something with the result     lt td onClick  loadxml   gt  lt i gt Click for Details lt  i gt  lt  td gt   function loadxml         result   loadScriptWithAjax   script php event button clicked        alert result         script php  lt  php     if   GET  event       button clicked           echo    You clicked a button       gt

User · Answer

you can try this one also -      public function PHPFunction                     echo   lt script type  text javascript  gt                   test                 lt  script gt                lt script type  text javascript  gt      public function test                 alert  In test Function               lt  script gt

User · Answer

You may not be able to directly do this  but the Xajax library is pretty close to what you want  I will demonstrate with an example  Here s a button on a webpage    lt button onclick  xajax addCity     gt Add New City lt  button gt     Our intuitive guess would be that xajax addCity   is a Javascript function  right  Well  right and wrong  The cool thing Xajax allows is that we don t have any JS function called xajax addCity    but what we do have is a PHP function called addCity   that can do whatever PHP does     lt  php function addCity     echo  Wow        gt    Think about it for a minute  We are virtually invoking a PHP function from Javascript code  That over-simplified example was just to whet the appetite  a better explanation is on the Xajax site  have fun

User · Answer

try like this    lt  php  if your condition        echo   lt script gt  window onload   function          yourJavascriptFunction param1  param2        lt  script gt      gt

User · Answer

Per now  February 2012  there s a new feature for this  Check here  Code sample  taken from the web     lt  php   v8   new V8Js        basic js     JS    lt  lt  lt  EOT len   print  Hello           World        n    len  EOT   try     var dump  v8- gt executeString  JS   basic js       catch  V8JsException  e      var dump  e        gt

User · Answer

I don t accept the naysayers  answers  If you find some special package that makes it work  then you can do it yourself   So  I don t buy those answers  onClick is a kludge that involves the end-user  hence not acceptable   umesh came close  but it was not a standalone program   Here is such  adapted from his Answer    lt script type  quot text javascript quot  gt  function JSFunction         alert  In test Function         This demonstrates that the function was called    lt  script gt    lt  php    Call a JS function  quot from quot  php  if  true         This if   is to point out that you might                  want to call JSFunction conditionally        An echo like this is how you implant the  call  in a way        that it will be invoked in the client      echo   lt script type  quot text javascript quot  gt           JSFunction         lt  script gt

[php] How to call a JavaScript function from PHP?

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