AJAX - PHP - JS. Send data to PHP and back do JS - Method 1

gistfile1.txt

//Method 1
//Js is not dynamic. I can not pass variables from PHP->to JS->to PHP, in the same page.


//Your php code
        $arrToJSON = array(
        "dataPHPtoJs"=>"yourData",
        "asYouWant"=>"<div class=\".class1\">soemting</div>"    
        );  
        return json_encode(array($arrToJSON));




    //Your javaScript code
    $(document).on("event", "#idElement", function(){
        //Data you want to send to php evaluate
         var dt={ 
                  ObjEvn:"btn_Login",
                  dataJsToPHP: $("#txt_EmailLogin").val()
                };

        //Ajax      
         var request =$.ajax({//http://api.jquery.com/jQuery.ajax/
                                url: "yourServer.php",
                                type: "POST",
                                data: dt,
                                dataType: "json"
                            });

        //Ajax Done catch JSON from PHP 
            request.done(function(dataset){
                for (var index in dataset){ 
                     dataPHPtoJsJS=dataset[index].dataPHPtoJs;
                     asManyasYouWantJS=dataset[index].asYouWant;
                 }

                 //JavaScript conditions. Here you can control the behaivior of your html object, based on your PHP response
                 if(dataPHPtoJsJS){
                    $( "#idYourHtmlElement" ).removeClass( "class1" )
                    $( "#idYourHtmlElement" ).addClass( "class2" )
                 }


         }); 

        //Ajax Fail 
            request.fail(function(jqXHR, textStatus) {
                alert("Request failed: " + textStatus);
            }); 
    }