Automatically Add Caption in image

Question

I want to automatically add caption for each picture appears in the name of the image or the alternative text

example Caption add automatic

Answer 1

You can add programmatically caption, alt, description every time you upload image at backend.

https://brutalbusiness.com/automatically-set-the-wordpress-image-title-alt-text-other-meta/

I tried myself this and worked nice as your expectation. This is for all your future upload images.

Try this and let me know.

/* Automatically set the image Title, Alt-Text, Caption & Description upon upload
--------------------------------------------------------------------------------------*/
add_action( 'add_attachment', 'my_set_image_meta_upon_image_upload' );
function my_set_image_meta_upon_image_upload( $post_ID ) {

    // Check if uploaded file is an image, else do nothing

    if ( wp_attachment_is_image( $post_ID ) ) {

        $my_image_title = get_post( $post_ID )->post_title;

        // Sanitize the title:  remove hyphens, underscores & extra spaces:
        $my_image_title = preg_replace( '%\s*[-_\s]+\s*%', ' ',  $my_image_title );

        // Sanitize the title:  capitalize first letter of every word (other letters lower case):
        $my_image_title = ucwords( strtolower( $my_image_title ) );

        // Create an array with the image meta (Title, Caption, Description) to be updated
        // Note:  comment out the Excerpt/Caption or Content/Description lines if not needed
        $my_image_meta = array(
            'ID'        => $post_ID,            // Specify the image (ID) to be updated
            'post_title'    => $my_image_title,     // Set image Title to sanitized title
            'post_excerpt'  => $my_image_title,     // Set image Caption (Excerpt) to sanitized title
            'post_content'  => $my_image_title,     // Set image Description (Content) to sanitized title
        );

        // Set the image Alt-Text
        update_post_meta( $post_ID, '_wp_attachment_image_alt', $my_image_title );

        // Set the image meta (e.g. Title, Excerpt, Content)
        wp_update_post( $my_image_meta );

    } 
}

Answer 2

To put in a plugin, these solutions came from eskimo and sam.. we simply select all the attachment where the post_excpert is empty and udpate it , put the title of it in description and caption when they are empty

    $s_query = "SELECT ID, post_title FROM `wp_posts` WHERE NOT post_content <=> post_title AND post_type='attachment'";
        $r_result = mysql_query($s_query);

        if($r_result)
        {
            while($row = mysql_fetch_row($r_result)){
                $s_update_query = 'UPDATE `wp_posts` SET post_content="'.$row[1].'", post_excerpt="'.$row[1].'" WHERE ID="'.$row[0].'"';
                mysql_query($s_update_query);
            }
        }

Here another similar query for the same result:

    mysql_select_db(DB_NAME)
or die("Unable to select database: " . mysql_error());
$query = "SELECT * FROM wp_posts WHERE post_type= 'attachment' AND post_excerpt= ''";
$result = mysql_query($query);
if (!$result) die ("Database access failed: " . mysql_error());
$rows = mysql_num_rows($result);
$query = "UPDATE wp_posts SET post_excerpt=post_title WHERE post_type='attachment' AND post_excerpt=''";
$result = mysql_query($query);
if (!$result) die ("Database access failed: " . mysql_error());

So with these solution we can import(SELECT) many image in wp gallery.Firstly the caption doesn't appear, we need to update (UPDATE)the post to see it in front end.