CODEWITHSUNDEEP
phpjavascriptajax
user1825130
user1825130

Reputation: 11

php variable to javascript via ajax

Ok im tring to get PHP variable to javascript variable via ajax.

i have some piece of php code to make this variable it look like this: (i wont put entire code because its working so only relevant code for this topic. i have new_m variable which is ARRAY and i want to pass it)

shuffle($new_m); 
echo json_encode($new_m);

then i have js file which should catch that echo and it look like this:

function getXMLHttp() 
{
  var xmlHttp

  try
  {
    //Firefox, Opera 8.0+, Safari
    xmlHttp = new XMLHttpRequest();
  }
  catch(e)
  {
    //Internet Explorer
    try
    {
      xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch(e)
    {
      try
      {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch(e)
      {
        alert("Your browser does not support AJAX!")
        return false;
      }
    }
  }
  return xmlHttp;
}

function MakeRequest() 
{
  var xmlHttp = getXMLHttp();

  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      var myvar = new Array();
    var myvar=JSON.parse(xmlHttp.responseText);


return myvar;


    }

  }
   xmlHttp.open("GET", "showimage.php", true);
  xmlHttp.send(null);
}

When this code is not on separate page like here and when is myvar is used inside function it works (because i have used this code on another page successfully). So i think my problem is not returning correct variable or not returning it on correct way.

and final piece of code is part where this myvar should be used it looks like:

<script type="text/javascript" src="js/shuffle.js"></script>
<title>undf</title>
</head>
<body onload="MakeRequest()">


<script type="text/javascript">
alert(myvar);
var pos = 0;
var imgs = myvar;
</script>

and nothing happens. im still new at this ajax and javascript. thanks for you help in advance.

Upvotes: 0

Views: 160

Answers (1)

nickb
nickb

Reputation: 59699

Your problem is that when alert( myvar); is executed, the request to the server hasn't happened yet, and the variable is undefined (not to mention that I believe the variable is out of scope, so you can't access it).

You should set up the JS so that when the window loads, you execute the request to retrieve the data and then read it:

<script type="text/javascript">
window.onload = function() {
    var myvar = MakeRequest();
    alert( myvar);
}
</script>

You can then get rid of the onload within the <body> tag.

Note that I'm not entirely sure that you're returning the value from the MakeRequest() function correctly, since the return is within the xmlhttp callback and not in the function. You should investigate this and verify.

Upvotes: 3

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