Without a post title, Attachments become significantly harder to use as they no longer have a title that can be clicked on. If you’re processing attachments and generating html manually I recommend using another piece of attachment meta, or just filling in appropriate titles, after all an image is a picture of something, let that … Read more
Upload iPhone video clips to blog via native WP app
If I remember right you need to chdir() into your custom uploads directory (before saving anything there) so that paths are correctly processed and saved in meta.
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So $img->post_excerpt is your content. It is the attachment’s caption field. You must change the images’ captions attached to the post with the id 54 in order to see any changes , if I understood the question right. ADD: Also attach the images to the post.
attachment_fields_to_edit is still there in 3.6. It is in /wp-admin/includes/media.php in a couple of places. Perhaps usage has changed, or something has changed that has broken your code but without that code it is impossible to tell.