Picture running a thriving e-commerce website powered by WordPress – you’re dealing with hundreds of product images daily. They come in multiple varieties: high resolution, various color options, different sizes, each carrying separate attention to detail. As the site owner, your primary objective is to serve your customers with the finest clarity and detail each product offers. You remember the WordPress function ‘wp_get_attachment_image_url’ can do just the trick!
This trusty helper translates all the complex and disparate image details you wrestle with into a neat, user-friendly visual presentation on your customers’ screens. That includes perfectly sized product thumbnails that match what buyers expect the product to look like. These nimble adjustments improve user experience, keep the site light and loading fast – all achieved by this single function.
Syntax
| <?php | |
| wp_get_attachment_image_url( $attachment_id, $size = 'thumbnail', $icon = false ); |
Parameters
$attachment_id(integer): The identifier of the image attachment.$size(string|array) – Optional: The size of the image. Accepts either a registered image size name or an array representing width and height values in pixels. Default is'thumbnail'.$icon(boolean) – Optional: Determines if the image should be treated as an icon. Default isfalse.
Return Value
- (string|false): Returns the URL of the requested image attachment if one exists, or
falseif there is no available image. If the specified$sizedoes not match any registered image size, then the URL of the original (unmodified) image will be returned.
How it Works
| <?php | |
| /** | |
| * Gets the URL of an image attachment. | |
| * | |
| * @since 4.4.0 | |
| * | |
| * @param int $attachment_id Image attachment ID. | |
| * @param string|int[] $size Optional. Image size. Accepts any registered image size name, or an array of | |
| * width and height values in pixels (in that order). Default 'thumbnail'. | |
| * @param bool $icon Optional. Whether the image should be treated as an icon. Default false. | |
| * @return string|false Attachment URL or false if no image is available. If `$size` does not match | |
| * any registered image size, the original image URL will be returned. | |
| */ | |
| function wp_get_attachment_image_url( $attachment_id, $size = 'thumbnail', $icon = false ) { | |
| $image = wp_get_attachment_image_src( $attachment_id, $size, $icon ); | |
| return isset( $image[0] ) ? $image[0] : false; | |
| } |
The wp_get_attachment_image_url() function fetches and returns the URL for a specific image attachment. It acts as a wrapper function for wp_get_attachment_image_src(), which returns an array containing details about the requested attachment.
Within wp_get_attachment_image_url(), it first calls wp_get_attachment_image_src() passing in parameters for $attachment_id, $size, and $icon. This means that wp_get_attachment_image_src() will be responsible for retrieving information about the specified attachment.
Once wp_get_attachment_image_src() processes these parameters, it looks for the corresponding image URL and returns an array containing additional media data including its width, height, file location, etc.
After receiving data from wp_get_attachment_image_src(), we check if index 0 of this array exists using isset(). In case it does exist, which points to an actual URL value at index 0 in most cases, we return the URL by accessing $image[0]. Otherwise, it indicates that no image is available or specified $size does not match any registered image size, thus returning false.
Usage Examples
Using Advanced Custom Fields (ACF)
ACF allows you to create custom fields for different types of content in WordPress. Let’s say you have a plugin that adds an image field to your custom post type called “Product” using ACF. You want to retrieve and display the URL of the attached image on your frontend.
| <?php | |
| // Assuming you have created an ACF image field for the "Product" custom post type with the field name 'product_image' | |
| // Get the ID of the current "Product" post | |
| $product_id = get_the_ID(); | |
| // Retrieve the URL of the attached image using wp_get_attachment_image_url() | |
| $product_image_url = wp_get_attachment_image_url(get_field('product_image', $product_id) , 'full'); | |
| // Display the image on your front-end | |
| echo '<img src="' . $product_image_url . '">'; |
In this example:
- First, we get the ID of the current “Product” post using
get_the_ID(). - Next, we use ACF’s
get_field()function to retrieve the attachment ID stored in our custom field ‘product_image’. - We then pass this attachment ID along with
'full'as the second parameter towp_get_attachment_image_url().
This will fetch and return the URL of the full-size attached image. - Finally, we escape and display the retrieved image URL using an HTML “ tag on our front-end.
Inside a Theme – Thumbnail Image
Let’s say you are developing a theme that has a blog page where you want to display thumbnails for each post. You can use wp_get_attachment_image_url() to easily retrieve and display these thumbnail images.
| <?php | |
| // Assuming you are inside your theme's loop | |
| // Get the ID of each blog post | |
| $post_id = get_the_ID(); | |
| // Retrieve the URL of the thumbnail image using wp_get_attachment_image_url() | |
| $thumbnail_url = wp_get_attachment_image_url(get_post_thumbnail_id($post_id) , 'thumbnail'); | |
| // Display the thumbnail image on your blog page | |
| echo '<img src="' . $thumbnail_url . '">'; |
In this example:
- Inside your theme’s loop, we first obtain the ID of each blog post using
get_the_ID(). - Next, we use
get_post_thumbnail_id()to retrieve the attachment ID of the post’s featured image. - We pass this attachment ID along with
'thumbnail'as the second parameter towp_get_attachment_image_url().
This will fetch and return the URL of the thumbnail-size attached image. - Finally, we escape and display the retrieved thumbnail image URL using an HTML
tag wrapped inside a link () to provide a clickable link to each blog post.
