I have created a Facebook App to upload photos to facebook from image url with help of some tutorials. It needs an image url and description. I want to put a button "Upload to Facebook" below every "Image" type posts in wordpress.

App Main Part to upload images -

try {
    $graph_url= "https://graph.facebook.com/me/photos?"
  . "url=" . urlencode($_POST["source"])
  . "&message=" . urlencode($_POST['message'])
  . "&method=POST"
  . "&access_token=" .$access_token;
  catch (FacebookApiException $e) {
    error_log('Could not post image to Facebook.');

    <form enctype="multipart/form-data" action=" " method="POST">
        Paste an image URL here:
        <input name="source" type="text"><br/><br/>
        Say something about this photo:
        <input name="message"
               type="text" value=""><br/><br/>
        <input type="submit" value="Upload" class="btn btn-primary"/><br/>

How can i extract image src dynamically from a custom post type(Image), and set src as source in form automatically. (There is only one image in every image type post)

  • Where is the image src located? post_content?
    – s_ha_dum
    Jun 2, 2013 at 17:05
  • image src is in post content. I don't know how i'll extract that. May be with get_post_meta. I don't know, that's why i posted my query here.
    – Prateek
    Jun 2, 2013 at 17:09

2 Answers 2


There is no built-in way to extract an image/image-src from the post body. If the images are attachments you can do it with get_children or WP_Query, and wp_get_attachment_image_src.

function get_image_src_from_content_101578($content) {
  global $post;
  $args = array( 
    'post_parent' => $post->ID,
  $images = get_children($args);
  foreach ($images as $img) {

You could also use regex.

function replace_image_link_101578($content) {
  $pattern = '|<img.*?src="([^"]*)".*?/?>|';
  $content = preg_match($pattern,$content,$matches);
  return $content;

The latter might be less work for the server, but may also be less reliable. If you have images embedded that aren't attachments, it will be your only choice though.

A non-hook example that returns only the image src attribute, if found.

function replace_image_link_($content) {
  $pattern = '|<img.*?src="([^"]*)".*?/?>|';
  $content = preg_match($pattern,$content,$matches);
  return (!empty($matches[1])) ? $matches[1] : '';
  • Images are wordpress media files, but i didn't attached them, i embedded them. So i need image src as source for that app form.
    – Prateek
    Jun 3, 2013 at 3:24
  • Then the second option-- the one with the preg_match-- should extract the image source.
    – s_ha_dum
    Jun 3, 2013 at 3:27
  • ok i'll try it, but how i gonna send it to that app page?
    – Prateek
    Jun 3, 2013 at 3:41
  • Just feed the post content into that function. It doesn't have to be a filter. The function will process whatever you give it. Run the function, look at the var_dump and you should see the image src that you need. Take that and do with it whatever you want.
    – s_ha_dum
    Jun 3, 2013 at 3:45
  • 4
    I can't write this whole thing for you! You asked how to extract the image source. I told you. If you are asking how the Facebook API works you are off-topic. I understand that you say you "don't know PHP" but is so you shouldn't be writing PHP until you take some time to learn at least the basics, and "how do I call a function?" is pretty basic. No offense intended.
    – s_ha_dum
    Jun 3, 2013 at 19:56

get_children() is not a reliable way of getting all images in a post, because it uses the post_parent column in the wp_posts table to decide which images belong to a post. The problem is that post_parent of an image only points to the post that first used this image.

If other posts use the same image, get_children won't find it if run on that post, so your list of images will be incomplete and only contain images that have been attached for the first time.

  • While I think this is good info, maybe it's better as a comment on the other answer, since it doesn't answer the original question itself. :)
    – Rarst
    Jul 24, 2017 at 15:57

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