[post] How do you post to an iframe?

How do you post data to an iframe?

An iframe is used to embed another document inside a html page.

If the form is to be submitted to an iframe within the form page, then it can be easily acheived using the target attribute of the tag.

Set the target attribute of the form to the name of the iframe tag.

<form action="action" method="post" target="output_frame">
    <!-- input elements here --> 
</form>
<iframe name="output_frame" src="" id="output_frame" width="XX" height="YY">
</iframe>           

Advanced iframe target use
This property can also be used to produce an ajax like experience, especially in cases like file upload, in which case where it becomes mandatory to submit the form, in order to upload the files

The iframe can be set to a width and height of 0, and the form can be submitted with the target set to the iframe, and a loading dialog opened before submitting the form. So, it mocks a ajax control as the control still remains on the input form jsp, with the loading dialog open.

Exmaple

<script>
$( "#uploadDialog" ).dialog({ autoOpen: false, modal: true, closeOnEscape: false,                 
            open: function(event, ui) { jQuery('.ui-dialog-titlebar-close').hide(); } });

function startUpload()
{            
    $("#uploadDialog").dialog("open");
}

function stopUpload()
{            
    $("#uploadDialog").dialog("close");
}
</script>

<div id="uploadDialog" title="Please Wait!!!">
            <center>
            <img src="/imagePath/loading.gif" width="100" height="100"/>
            <br/>
            Loading Details...
            </center>
 </div>

<FORM  ENCTYPE="multipart/form-data" ACTION="Action" METHOD="POST" target="upload_target" onsubmit="startUpload()"> 
<!-- input file elements here--> 
</FORM>

<iframe id="upload_target" name="upload_target" src="#" style="width:0;height:0;border:0px solid #fff;" onload="stopUpload()">   
        </iframe>

If you want to change inputs in an iframe then submit the form from that iframe, do this

...
var el = document.getElementById('targetFrame');

var doc, frame_win = getIframeWindow(el); // getIframeWindow is defined below

if (frame_win) {
  doc = (window.contentDocument || window.document);
}

if (doc) {
  doc.forms[0].someInputName.value = someValue;
  ...
  doc.forms[0].submit();
}
...

Normally, you can only do this if the page in the iframe is from the same origin, but you can start Chrome in a debug mode to disregard the same origin policy and test this on any page.

function getIframeWindow(iframe_object) {
  var doc;

  if (iframe_object.contentWindow) {
    return iframe_object.contentWindow;
  }

  if (iframe_object.window) {
    return iframe_object.window;
  } 

  if (!doc && iframe_object.contentDocument) {
    doc = iframe_object.contentDocument;
  } 

  if (!doc && iframe_object.document) {
    doc = iframe_object.document;
  }

  if (doc && doc.defaultView) {
   return doc.defaultView;
  }

  if (doc && doc.parentWindow) {
    return doc.parentWindow;
  }

  return undefined;
}

This function creates a temporary form, then send data using jQuery :

function postToIframe(data,url,target){
    $('body').append('<form action="'+url+'" method="post" target="'+target+'" id="postToIframe"></form>');
    $.each(data,function(n,v){
        $('#postToIframe').append('<input type="hidden" name="'+n+'" value="'+v+'" />');
    });
    $('#postToIframe').submit().remove();
}

target is the 'name' attr of the target iFrame, and data is a JS object :

data={last_name:'Smith',first_name:'John'}