CODEWITHSUNDEEP
jqueryhtml2canvas
Bharath Kumar
Bharath Kumar

Reputation: 860

html2canvas not rendering CDN images

I'm trying to get screenshot using html2canvas. It's working fine for text but it is not rendering CDN images, if i host the images in server it was working fine but if trying to load images from CDN links those image were not rendering.

My code is:

index.php

<div id="target">
     <img id="editor_Img_1" src="http://d2j259rizy5u5h.cloudfront.net/outputvideos/thumbs/email_44_2015_03_02_54f462457526c-00001.png" alt="event-video" style="height: 200px; width: 320px;">
</div>

function capture() {
    $('#target').html2canvas({
        onrendered: function (canvas) {
            var img = canvas.toDataURL();
            console.log(img);
            $('<img>',{src:img}).appendTo($('img'));
            //Set hidden field's value to image data (base-64 string)
            $('#img_val').val(canvas.toDataURL("image/png"));
            //Submit the form manually
            document.getElementById("myForm").submit();
        }
    });
}

Save.php

<?php
    //Get the base-64 string from data
    $filteredData=substr($_POST['img_val'], strpos($_POST['img_val'], ",")+1);

    //Decode the string
    $unencodedData=base64_decode($filteredData);

    echo $filteredData;

    //Save the image
    file_put_contents('img.png', $unencodedData);
?>
<h2>Save the image and show to user</h2>
<table>
<tr>
    <td>
        <a href="img.png" target="blank">
            Click Here to See The Image Saved to Server</a>
    </td>
    <td align="right">
        <a href="index.php">
            Click Here to Go Back</a>
    </td>
</tr>
<tr>
    <td colspan="2">
        <br />
        <br />
        <span>
            Here is Client-sided image:
        </span>
        <br />
        <?php
            //Show the image
            echo '<img src="'.$_POST['img_val'].'" />';
        ?>
     </td>
</tr>
</table>

Upvotes: 3

Views: 7453

Answers (2)

AKNair
AKNair

Reputation: 1587

You can do so by passing one of the option in html2canvas function. 

html2canvas(document.body,
{
   useCORS: true, //By passing this option in function Cross origin images will be rendered properly in the downloaded version of the PDF
   onrendered: function (canvas) {
     //your functions here
   }
});

Upvotes: 4

Bhavin Solanki
Bhavin Solanki

Reputation: 4818

OK, well I figured out what the problem is. html2canvas can't capture an image if it's not from the same origin. Images are coming from a CDN. There are some limitation to html to canvas

Limitations

All the images that the script uses need to reside under the same origin for it to be able to read them without the assistance of a proxy. Similarly, if you have other canvas elements on the page, which have been tainted with cross-origin content, they will become dirty and no longer readable by html2canvas.

The script doesn't render plugin content such as Flash or Java applets. It doesn't render iframe content either.

Documentation

Upvotes: 2

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