how to html form post - file uploading and reading json response from php server

Question

i am trying file uploading to php my server.file and data uploading through multi part /form-data ,the file and data received on php server but in my php server return json response .please help me how to read json response in my webpage and if its success(code=0) means it redirect another page .the php sever is common for both android and web pages .json response look like {"code":0,"message":"success"}

<div style="height:0px;overflow:hidden">
    <form id="myForm" action="http://192.168.2.4/digiid/api/addid" 
        method="post" enctype="multipart/form-data" runat="server">

        <input type="file" name="file" id="file" onchange="showMyImage(this)" />
        <input type="hidden" name="userid" value="<?php echo $_SESSION["userid"]?>">
        <input type="hidden" id="inputfilename" name="filename" value="here">
    </form>
</div>

<a class="button1" id="browseButton" onclick=""  style="width:12%;height: 30px; text-decoration:none;"><font color="white" size="5px">Select ID</font></a>
<br/>

<div>

            <img src='images/capture_picture_size.png' id='imgscreen'  width='200' height='200'>

<br/>


<p id="filename" style="color: #ffffff; font-size: 20px" >
    Title of the ID<br/></p>

<a class="button1"onclick="myFunction()" style= " width:12%;height: 30px; text-decoration:none;"><font color="white" size="5px">Save ID</font></a></form>

</div>  

<script>
    function myFunction() {
       document.getElementById("myForm").submit();
    }
</script>

<script>
    browseButton.onclick=function chooseFile() {
        document.getElementById("file").click(); 
    };

    function showMyImage(fileInput) {

        var files = fileInput.files;

        var file = files[0];
        var imageType = /image.*/;

        var img=document.getElementById("imgscreen");
        var reader = new FileReader();
        reader.onload = (function(aImg) {
            return function(e) {
            //x=e.target.result

            img.src = e.target.result;
            var extfilename=file.name;
            document.getElementById("filename").innerHTML=extfilename.slice(0,-5) ;

            document.getElementById("inputfilename").value=extfilename.slice(0,-5);
     };
 })(img);

 reader.readAsDataURL(file);

 }</script>

Answer 1

I think it should work for you. Using AJAX, as I do

     //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);
            }); 
    }