WordPress: How to auto set featured image using the first image in post

Introduction

If you are a heavy editor in WordPress, you may find out that most of the time, you just set the first image of your post to be the featured image. Here’s a quick and handy way to help you skip the tedious work and save some labor.

Use Easy Add Thumbnail plugin

The easiest way to automate this is to install the Easy Add Thumbnail plugin by Samuel Aguilera.

Just install, activate it and you’re good to go.

Once activated, this plugin will automatically set the post’s featured image to be the first image in your post content if your post doesn’t have a featured image yet.

If you want to select your own featured image, it will leave the featured image untouched and display your selection instead.

How this works

Let’s take a look at the plugin’s code, which is very simple.

if ( function_exists( 'add_theme_support' ) ) {

    add_theme_support( 'post-thumbnails' ); // This should be in your theme. But we add this here because this way we can have featured images before swicth to a theme that supports them.

    function easy_add_thumbnail($post) {

        $already_has_thumb = has_post_thumbnail();
        $post_type = get_post_type( $post->ID );
        $exclude_types = array('');
        $exclude_types = apply_filters( 'eat_exclude_types', $exclude_types );

        // do nothing if the post has already a featured image set
        if ( $already_has_thumb ) {
            return;
        }

        // do the job if the post is not from an excluded type
        if ( ! in_array( $post_type, $exclude_types ) ) {
            // get first attached image
            $attached_image = get_children( "order=ASC&post_parent=$post->ID&post_type=attachment&post_mime_type=image&numberposts=1" );

            if ( $attached_image ) {
                $attachment_values = array_values( $attached_image );
                // add attachment ID
                add_post_meta( $post->ID, '_thumbnail_id', $attachment_values[0]->ID, true );
            }
        }
    }

    // set featured image before post is displayed (for old posts)
    add_action('the_post', 'easy_add_thumbnail');

    // hooks added to set the thumbnail when publishing too
    add_action('new_to_publish', 'easy_add_thumbnail');
    add_action('draft_to_publish', 'easy_add_thumbnail');
    add_action('pending_to_publish', 'easy_add_thumbnail');
    add_action('future_to_publish', 'easy_add_thumbnail');
}

What this code does is that it creates a function called easy_add_thumbnail, which checks if a featured image has been set for your post, and then if a featured image hasn’t been set, it will scan through the images in your post and assign one of them to be the featured image.

Next, this code hooks that easy_add_thumbnail function to the post editing events so that the function will be called every time the post is published or displayed (for old posts).

If you don’t want to install the plugin, you can just add this code snippet to your theme’s function.php file or create your own plugin, whichever you prefer.

Does Easy Add Thumbnail plugin work well with Image Teleporter plugin?

If you don’t know it yet, Image Teleporter plugin helps you upload all the external hosted images in your post to your WordPress hosting and then change the images’ url correspondingly.

Fortunately, Easy Add Thumbnail works well with Image Teleporter. This means that even if the images in your post are hosted externally, when you update or publish your post, the Image Teleporter will first upload them to your hosting and attach the new internally hosted images to your post; then the Easy Add Thumbnail plugin will pick the first among those internal hosted images and set it as the featured image (if you haven’t specified a featured image by that time).

Bonus tip

If you want to check if your posts have featured image or not right in the “All posts” page, try the plugin in this post. Once installed and activated, this plugin adds a column to the posts listing page with the featured image if it exists.

 

Did you find this post helpful?

What are your favorite WordPress tips? Let me know in the comment! 😀