Implementing Image Zoom in Your WordPress Plugin

Posted on 16th June 2023

The process of implementing image zoom in your WordPress plugin is fairly straightforward. In this article, we will walk you through the process step-by-step.

1. Install and activate the jQuery Image Zoom plugin

First, you will need to install and activate the jQuery Image Zoom plugin. You can do this from the Plugins page of your WordPress admin panel.

2. Add the following code to your plugin

Once the plugin is activated, you will need to add the following code to your plugin:

$(document).ready(function(){

$(‘.zoom’).imagezoom();

});

This code will enable the image zoom feature for all images with the class “zoom”.

3. That’s it!

That’s all you need to do to add image zoom to your WordPress plugin. Your users will now be able to zoom in on images to see them in more detail.

In your WordPress plugin, you may want to offer your users the ability to zoom in on images. This can be a great way to give them a closer look at something, or to simply make things easier to see.

There are a few different ways that you can go about implementing image zoom in your WordPress plugin. In this article, we’ll discuss two of the most popular methods: using the WP_Image_Editor class, and using the jQuery Zoom plugin.

Using the WP_Image_Editor Class

The WP_Image_Editor class was introduced in WordPress 3.5 and allows for the manipulation of images. This includes methods for cropping, resizing, and rotating images.

To use the WP_Image_Editor class, you’ll first need to include the class in your plugin. You can do this by using the require_once() function:

require_once( ABSPATH . WPINC . ‘/class-wp-image-editor.php’ );

Once the class is included, you can create a new instance of it by passing in the path to the image you want to edit:

$editor = new WP_Image_Editor( ‘/path/to/image.jpg’ );

From there, you can use the methods of the class to manipulate the image however you see fit. For our purposes, we’ll use the resize() method to make the image smaller. This will allow us to make it fit within a smaller container on the page without losing quality:

$editor->resize( 200, 200 );

Finally, we can save the edited image back to its original location using the save() method:

$editor->save( ‘/path/to/image.jpg’ );

Using the jQuery Zoom Plugin

If you prefer not to use the WP_Image_Editor class, or if you’re not running WordPress 3.5 or higher, you can use the jQuery Zoom plugin. This plugin is a bit more user-friendly, and doesn’t require any PHP coding.

To use the jQuery Zoom plugin, first, you’ll need to download it and include the JavaScript file in your plugin. You can do this by using the wp_enqueue_script() function:

wp_enqueue_script( ‘jquery-zoom’, plugins_url( ‘jquery.zoom.min.js’, __FILE__ ), array( ‘jquery’ ), ‘1.7.21’, true );

Once the script is included, you can activate the zoom effect by adding a few lines of JavaScript to your plugin. In this example, we’ll activate the zoom effect when the user mouses over the image:

jQuery(document).ready(function($){ $(‘#my-image’).zoom(); });

You can also pass in options to the zoom() method to customize the behavior of the zoom effect. For example, you can set the zoom level, the zoom type, and the duration of the effect:

jQuery(document).ready(function($){ $(‘#my-image’).zoom({ zoomLevel: 2, // the zoom level duration: 500, // the duration of the effect zoomType: ‘inner’ // the zoom type (inner, outer, window) }); });

Conclusion

In this article, we’ve discussed two methods for implementing image zoom in your WordPress plugin. Using the WP_Image_Editor class or the jQuery Zoom plugin can be a great way to give your users a closer look at images.

Before we get started, there are a few things we need to take care of. The first is to enqueue the jQuery UI script and stylesheet. In your plugin, create a new function and hook it to the wp_enqueue_scripts action:

function wp_enqueue_scripts() {
wp_enqueue_script( ‘jquery-ui-dialog’ );
wp_enqueue_style( ‘wp-jquery-ui-dialog’ );
}
add_action( ‘wp_enqueue_scripts’, ‘wp_enqueue_scripts’ );

Next, we need to include the jQuery UI Dialog files. You can do this by enqueuing the file in your plugin, or by adding the following code to your theme’s functions.php file:

if ( !is_admin() ) {
wp_enqueue_script( ‘jquery-ui-dialog’ );
wp_enqueue_style( ‘wp-jquery-ui-dialog’ );
}

Now that we have the jQuery UI Dialog files included, we can start writing the code for our image zoom feature.

The first thing we need to do is create a new function to display the image zoom dialog. This function will be responsible for outputting the HTML for the dialog, as well as the JavaScript code needed to create the dialog.

function image_zoom_dialog() {
?>

jQuery( document ).ready( function( $ ) {
$( ‘#image-zoom-dialog’ ).dialog( {
autoOpen: false,
width: 600,
height: 400,
modal: true
} );
} );

‘Image Zoom URL’,
‘input’ => ‘text’,
‘value’ => get_post_meta( $post->ID, ‘_image_zoom_url’, true ),
);
return $fields;
}
add_filter( ‘attachment_fields_to_edit’, ‘attachment_fields_to_edit’, 10, 2 );

This code adds a new text field to the attachment edit screen. The field contains the image zoom URL, which is retrieved from the post meta data.

Now that we have the image zoom URL field, we need to save the value of this field when the attachment is saved. This can be done by hooking into the attachment_fields_to_save filter.

function attachment_fields_to_save( $post, $attachment ) {
update_post_meta( $post[‘ID’], ‘_image_zoom_url’, $attachment[‘image_zoom_url’] );
return $post;
}
add_filter( ‘attachment_fields_to_save’, ‘attachment_fields_to_save’, 10, 2 );

This code saves the image zoom URL when the attachment is saved.

Now that we have the image zoom URL saved, we can write the code to display the image in the dialog. This can be done by hooking into the wp_footer action and outputting the JavaScript code needed to open the dialog.

function wp_footer() {
?>

jQuery( document ).ready( function( $ ) {
$( ‘.wp-image-zoom’ ).click( function( e ) {
e.preventDefault();
var image_zoom_url = $( this ).attr( ‘href’ );
$( ‘#image-zoom-dialog img’ ).attr( ‘src’, image_zoom_url );
$( ‘#image-zoom-dialog’ ).dialog( ‘open’ );
} );
} );

<?php
}
add_action( 'wp_footer', 'wp_footer' );

This code outputs the JavaScript code needed to open the dialog. The code uses the jQuery click() method to bind a click event handler to all elements with the class wp-image-zoom. When an element with this class is clicked, the dialog is opened and the image is displayed.

The last thing we need to do is add the wp-image-zoom class to our images. This can be done by hooking into the image_send_to_editor filter and adding the class to the image HTML.

function image_send_to_editor( $html, $id, $caption, $title, $align, $url, $size, $alt ) {
$html = '‘ . $html . ‘‘;
return $html;
}
add_filter( ‘image_send_to_editor’, ‘image_send_to_editor’, 10, 8 );

This code adds the wp-image-zoom class to the image HTML.

That’s all the code you need to implement image zoom in your WordPress plugin or theme.