Save a canvas image directly to your WordPress media library or server

Question

Save a canvas image directly to your WordPress media library or server

I'm working on integrating a feature that enables users to save a png created on a canvas element into the WordPress media library, or at least onto the server (which is an initial step before sharing the image on Facebook, as it requires a valid image URL).

Until now, I've been using JavaScript for everything, and am attempting to save the image to the server using an AJAX call. This is what my AJAX looks like so far:

$(document).on('click','.facebook',function(e){

var image = document.getElementById("canvas");
var imageURL = image.toDataURL();
$.ajax({
  type: "POST",
  url: "http://myexample.com",
  data: { 
 imgBase64: imageURL
}
}).done(function(o) {
 console.log('saved'); 
});

I'm also unsure about what should be included in the url field... I tried using the path for images in my actual media library, but encountered a "permission denied" error when trying to execute this.

Could someone provide assistance?

javascript ajax wordpress canvas media-library

Answer 1

Answer №1

It's important to have the admin ajax URL available for use in your code. One way to do this is by utilizing the ajaxurl JavaScript variable to point to the admin-ajax.php file. However, this variable is not automatically defined on the front end. To address this, you can declare it easily within the header.php of your theme.

<script type="text/javascript>
    var ajaxurl = "<?php echo admin_url('admin-ajax.php'); ?>";
</script>

Once the ajaxurl variable is set up, you can integrate it into your scripts like so:

$(document).on('click','.facebook',function(e){

var image = document.getElementById("canvas");
var imageURL = image.toDataURL();
$.ajax({
  type: "POST",
  url: ajaxurl,
  data: { 
 imgBase64: imageURL
}
}).done(function(o) {
 console.log('saved'); 
});

Answer 2

It's important to have the admin ajax URL available for use in your code. One way to do this is by utilizing the ajaxurl JavaScript variable to point to the admin-ajax.php file. However, this variable is not automatically defined on the front end. To address this, you can declare it easily within the header.php of your theme.

<script type="text/javascript>
    var ajaxurl = "<?php echo admin_url('admin-ajax.php'); ?>";
</script>

Once the ajaxurl variable is set up, you can integrate it into your scripts like so:

$(document).on('click','.facebook',function(e){

var image = document.getElementById("canvas");
var imageURL = image.toDataURL();
$.ajax({
  type: "POST",
  url: ajaxurl,
  data: { 
 imgBase64: imageURL
}
}).done(function(o) {
 console.log('saved'); 
});

Answer 3

Answer №2

It is uncertain if WordPress provides a REST API for image uploads, so here is an alternative method: You can establish a custom endpoint using the register_rest_route function.

Within this endpoint, you can manage the image upload process. Here's an example of creating a unique REST endpoint (http://example.com/imageHandler/v1/upload with POST method).

add_action( 'rest_api_init', function () {
    register_rest_route( '/imageHandler/v1', '/upload', array(
        'methods' => 'POST',
        'callback' => 'uploadImage',
    ) );
} );

function uploadImage($request) {
    $base64Image = $request['imgBase64'];
}

Inside the uploadImage function, you may consider utilizing this solution for base64 image uploads: https://gist.github.com/tjhole/3ddfc6cbf6da01c7ce0f, as WordPress itself cannot handle base64 uploads.

Upon successful upload, you can retrieve the image URL by invoking: wp_get_attachment_url.

Answer 4

It is uncertain if WordPress provides a REST API for image uploads, so here is an alternative method: You can establish a custom endpoint using the register_rest_route function.

Within this endpoint, you can manage the image upload process. Here's an example of creating a unique REST endpoint (http://example.com/imageHandler/v1/upload with POST method).

add_action( 'rest_api_init', function () {
    register_rest_route( '/imageHandler/v1', '/upload', array(
        'methods' => 'POST',
        'callback' => 'uploadImage',
    ) );
} );

function uploadImage($request) {
    $base64Image = $request['imgBase64'];
}

Inside the uploadImage function, you may consider utilizing this solution for base64 image uploads: https://gist.github.com/tjhole/3ddfc6cbf6da01c7ce0f, as WordPress itself cannot handle base64 uploads.

Upon successful upload, you can retrieve the image URL by invoking: wp_get_attachment_url.

Save a canvas image directly to your WordPress media library or server

Answer №1

Answer №2

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