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jQuery/JavaScript: accessing contents of an iframe

Posted by: admin November 2, 2017 Leave a comment

Questions:

I would like to manipulate the HTML inside an iframe using jQuery.

I thought I’d be able to do this by setting the context of the jQuery function to be the document of the iframe, something like:

$(function(){ //document ready
    $('some selector', frames['nameOfMyIframe'].document).doStuff()
});

However this doesn’t seem to work. A bit of inspection shows me that the variables in frames['nameOfMyIframe'] are undefined unless I wait a while for the iframe to load. However, when the iframe loads the variables are not accessible (I get permission denied-type errors).

Does anyone know of a work-around to this?

Answers:

I think what you are doing is subject to the same origin policy. This should be the reason why you are getting permission denied type errors.

Questions:
Answers:

If the <iframe> is from the same domain, the elements are easily accessible as

$("#iFrame").contents().find("#someDiv").removeClass("hidden");

Reference

Questions:
Answers:
$(document).ready(function(){
    $('#frameID').load(function(){
        $('#frameID').contents().find('body').html('Hey, i`ve changed content of <body>! Yay!!!');
    });
});

Questions:
Answers:

If the iframe src is from another domain you can still do it. You need to read the external page into PHP and echo it from your domain. Like this:

iframe_page.php

<?php
    $URL = "http://external.com"

    $domain = file_get_contents($URL)

    echo $domain
?>

Then something like this:

display_page.html

<html>
<head>
  <title>Test</title>
 </head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.1/jquery.min.js"></script>

<script>

$(document).ready(function(){   
    cleanit = setInterval ( "cleaning()", 500 );
});

function cleaning(){
    if($('#frametest').contents().find('.selector').html() == "somthing"){
        clearInterval(cleanit);
        $('#selector').contents().find('.Link').html('ideate tech');
    }
}

</script>

<body>
<iframe name="frametest" id="frametest" src="http://yourdomain.com/iframe_page.php" ></iframe>
</body>
</html>

The above is an example of how to edit an external page through an iframe without the access denied etc…

Questions:
Answers:

Use

iframe.contentWindow.document

instead of

iframe.contentDocument

Questions:
Answers:

I find this way cleaner:

var $iframe = $("#iframeID").contents();
$iframe.find('selector');

Questions:
Answers:

You need to attach an event to an iframe’s onload handler, and execute the js in there, so that you make sure the iframe has finished loading before accessing it.

$().ready(function () {
    $("#iframeID").ready(function () { //The function below executes once the iframe has finished loading
        $('some selector', frames['nameOfMyIframe'].document).doStuff();
    });
};

The above will solve the ‘not-yet-loaded’ problem, but as regards the permissions, if you are loading a page in the iframe that is from a different domain, you won’t be able to access it due to security restrictions.

Questions:
Answers:

You can use window.postMessage to call a function between page and his iframe (cross domain or not).

Documentation

page.html

<!DOCTYPE html>
<html>
<head>
    <title>Page with an iframe</title>
    <meta charset="UTF-8" />
    <script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
    <script>
    var Page = {
        id:'page',
        variable:'This is the page.'
    };

    $(window).on('message', function(e) {
        var event = e.originalEvent;
        if(window.console) {
            console.log(event);
        }
        alert(event.origin + '\n' + event.data);
    });
    function iframeReady(iframe) {
        if(iframe.contentWindow.postMessage) {
            iframe.contentWindow.postMessage('Hello ' + Page.id, '*');
        }
    }
    </script>
</head>
<body>
    <h1>Page with an iframe</h1>
    <iframe src="iframe.html" onload="iframeReady(this);"></iframe>
</body>
</html>

iframe.html

<!DOCTYPE html>
<html>
<head>
    <title>iframe</title>
    <meta charset="UTF-8" />
    <script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
    <script>
    var Page = {
        id:'iframe',
        variable:'The iframe.'
    };

    $(window).on('message', function(e) {
        var event = e.originalEvent;
        if(window.console) {
            console.log(event);
        }
        alert(event.origin + '\n' + event.data);
    });
    $(window).on('load', function() {
        if(window.parent.postMessage) {
            window.parent.postMessage('Hello ' + Page.id, '*');
        }
    });
    </script>
</head>
<body>
    <h1>iframe</h1>
    <p>It's the iframe.</p>
</body>
</html>

Questions:
Answers:

I prefer to use other variant for accessing.
From parent you can have a access to variable in child iframe.
$ is a variable too and you can receive access to its just call
window.iframe_id.$

For example, window.view.$('div').hide() – hide all divs in iframe with id ‘view’

But, it doesn’t work in FF. For better compatibility you should use

$('#iframe_id')[0].contentWindow.$

Questions:
Answers:

I create a sample code . Now you can easily understand from different domain you can’t access
content of iframe .. Same domain we can access iframe content

I share you my code , Please run this code
check the console . I print image src at console. There are four iframe , two iframe coming from same domain & other two from other domain(third party) .You can see two image src( https://www.google.com/logos/doodles/2015/googles-new-logo-5078286822539264.3-hp2x.gif

and

https://www.google.com/logos/doodles/2015/arbor-day-2015-brazil-5154560611975168-hp2x.gif
)
at console and also can see two permission error(
2
Error: Permission denied to access property ‘document’

…irstChild)},contents:function(a){return m.nodeName(a,”iframe”)?a.contentDocument…

) which is coming from third party iframe.

<body id="page-top" data-spy="scroll" data-target=".navbar-fixed-top">
<p>iframe from same domain</p>
  <iframe frameborder="0" scrolling="no" width="500" height="500"
   src="iframe.html" name="imgbox" class="iView">

</iframe>
<p>iframe from same domain</p>
<iframe frameborder="0" scrolling="no" width="500" height="500"
   src="iframe2.html" name="imgbox" class="iView1">

</iframe>
<p>iframe from different  domain</p>
 <iframe frameborder="0" scrolling="no" width="500" height="500"
   src="https://www.google.com/logos/doodles/2015/googles-new-logo-5078286822539264.3-hp2x.gif" name="imgbox" class="iView2">

</iframe>

<p>iframe from different  domain</p>
 <iframe frameborder="0" scrolling="no" width="500" height="500"
   src="http://d1rmo5dfr7fx8e.cloudfront.net/" name="imgbox" class="iView3">

</iframe>

<script type='text/javascript'>


$(document).ready(function(){
    setTimeout(function(){


        var src = $('.iView').contents().find(".shrinkToFit").attr('src');
    console.log(src);
         }, 2000);


    setTimeout(function(){


        var src = $('.iView1').contents().find(".shrinkToFit").attr('src');
    console.log(src);
         }, 3000);


    setTimeout(function(){


        var src = $('.iView2').contents().find(".shrinkToFit").attr('src');
    console.log(src);
         }, 3000);

         setTimeout(function(){


        var src = $('.iView3').contents().find("img").attr('src');
    console.log(src);
         }, 3000);


    })


</script>
</body>

Questions:
Answers:

Have you tried the classic, waiting for the load to complete using jQuery’s builtin ready function?

$(document).ready(function() {
    $('some selector', frames['nameOfMyIframe'].document).doStuff()
} );

K

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