ResponsiveImages Plugin for October CMS

Automatically generate and serve images for your visitor's viewport size without changing your theme!

Features

Responsive images
WebP conversion
Focuspoint
Inline SVG helper function

Responsive images

How it works

This plugin provides a middleware that adds srcset and sizes attributes to all locally served images in your html response.

It turns this

<img width="500" src="/storage/app/media/image.jpg">

into this

<img width="500" src="/storage/app/media/image.jpg" srcset="/storage/temp/public/be7/4d6/0cc/image__400.jpg 400w, /storage/temp/public/be7/4d6/0cc/image__768.jpg 768w, /storage/temp/public/be7/4d6/0cc/image__1024.jpg 1024w" sizes="(max-width: 500px) 100vw, 500px">

It automatically creates resized copies of the image and serves the most fitting one to your visitor.

All image copies are saved in your public temp path. Remote file systems are currently untested.

The images are generated on the first page load. Depending on the source image size this may take a few seconds. Subsequent page loads will be faster since the images are only resized once.

Configuration

Three image sizes are created by default: 400, 768 and 1024 pixels.

You can change these values by changing the settings in the backend.

Alternative `src` and `srcset` attributes

If you want to use an alternative src attribute you can change this via the backend settings page.

This is useful if you are using a plugin like jQuery.lazyLoad where the image is initially linked via a data-original attribute.

If your plugin requires an alternative srcset attribute (like verlok/LazyLoad) this can also be specified via the backend settings.

Global `class` attributes

If you want to add a class to every processed image you can configure this via the backend settings.

This is useful if you want to add Bootstrap's img-responsive class to all images on your website.

Pre-generate images

You can use the php artisan responsive-images:generate command to pre-generate responsive images. The command uses October's pages.menuitem.* events to build a list of all available URLs and pre-generates all images used on these pages.

Test results

I have tested this plugin on a page with 20 hd wallpapers from pixabay.

Viewport width	Transferred file size
1920 px	21.8 MB
1024 px	3.1 MB
768 px	2.0 MB
400 px	0.8 MB

Opt-out of processing

If for any reason you want an img tag to be completely ignored by this plugin, simply add the data-responsive="ignore" attribute to your tag:

<img src="dont-process-this.jpg" data-responsive="ignore" alt="">

Delete resized images

Use the php artisan responsive-images:clear command to delete all resized images. The next time a page/image is requested, the resized copies will be created again.

WebP conversion

This plugin provides an option to serve WebP images if the visiting Browser signals support for it.

Enable the WebP conversion in the backend settings. Enabling this option will add a rule to your .htaccess file, that checks for a {filename}.{extension}.webp image for every request and serves it to the client, if available.

Console command to convert images to WebP

The plugin includes a handy console command that you can run in a cronjob that iterates through your storage directories and converts images to WebP:

php artisan responsive-images:convert --include=storage/app

This command requires the cwebp to be available on your server. You can download it for your OS and provide the path to the binary using the --converter-path option.

Conversion errors

You can find a log of failed image conversions in the offline_responsiveimages_inconvertibles table. If the conversion for a file failed, it will be logged in this table. The conversion will not be retried for files that failed before. To force a retry, remove the file from the table table and run the conversion command again.

Support for other servers than Apache

If you do not use Apache, you have to configure your server to do the following:

Check if image/webp is present in the Accepts http header
Check if the requested image ends in jp(e)g or png
Check if the requested image + a .webp exists
If it does, serve it

Apache + .htaccess

If you are using Apache with mod_rewrite enabled, you do not have to do anything manually. The plugin will patch your .htaccess file if WebP support gets enabled.

Nginx

If you are using Nginx to serve your October website, you have to modify your server configuration manually.

The following example should give you a good starting point.

user www-data;

http {
  sendfile on;
  tcp_nopush on;
  tcp_nodelay on;

  include /etc/nginx/mime.types;
  default_type application/octet-stream;

  gzip on;
  gzip_disable "msie6";

  map $http_accept $webp_suffix {
    default   "";
    "~*webp"  ".webp";
  }

  # ...

  server {
    charset utf-8;
    listen 80;

    server_name localhost;
    root /var/www/html;
    index index.php;

    location ~ \.(jpe?g|png)$ {
	add_header Vary Accept;
        try_files $uri$webp_suffix $uri/;
    }

    # ...
  }
}

Your mime.types file should additionally list the webp mime type:

image/webp  webp;

Other servers

We did not invest in the proper WebP detection configuration for other server software. Based on the .htaccess example above and the webp-detect repo you should be able to figure out what config is needed.

If you have a working example please add it via a PR to this README!

Custom base directory path

If your application directory is located in a special location, you can set the RESPONSIVE_IMAGES_BASE_DIR environment variable to change the source path.

<IfModule mod_setenvif.c>
    SetEnv RESPONSIVE_IMAGES_BASE_DIR /path/to/your/dir
</IfModule>

Focuspoint

This feature has two components to it:

Backend

In the backend, the file upload widget is extended with a simple focus point selector.

To enable this extension simply set focuspoint: true to any fileupload widget in your plugin's fields.yaml. This feature is off by default.

Once it is enabled you can click on an uploaded image to select the focus point.

fields:
    images:
        label: Images
        mode: image
        useCaption: true
        thumbOptions:
            mode: crop
            extension: auto
        span: full
        type: fileupload
        # Enable the focus point selector
        focuspoint: true

Frontend

You can use the new focus method on any File model to get the source to a focus point image.

The focus method has the exact same API as the thumb method, you can specify a height, width and a mode.

<img src="{{ image.focus(200, 300, 'auto') }}" alt="">

This call will result in the following HTML:

<img src="/storage/temp/public/a9f/2bd/159/offline-focus_30_400_500_50_50_0_0_auto__400.jpg"
     alt=""
     class="focuspoint-image"
     style="width: 100%; height: 100%; object-fit: cover; object-position: 30% 80%;">

You can disable the injection of the inline styles via the plugin's backend settings.

If you want to use any of the existing focus point JS libraries you can also define a custom container that will be place around the image. The focus coordinates can be injected as custom data-* attributes.

All of these settings are available on the plugin's backend settings page.

<div class="focuspoint-container" data-focus-x="50" data-focus-y="30">
    <img src="/storage/temp/public/a9f/2bd/159/offline-focus_30_400_500_50_50_0_0_auto__400.jpg"
         alt=""
         class="focuspoint-image"
         data-focus-x="50"
         data-focus-y="30"
     >
 </div>

Browser-Compatibility

Be aware that object-fit is not supported in IE without using a polyfill.

Inlining SVG images

This plugin registers a simple svg helper function that enables you to inline SVG images from your project.

<!-- search in theme directory -->
<div class="inline-svg-wrapper">
	{{ svg('assets/icon.svg') }}
</div>

<!-- start with a / to search relative to the project's root -->
<div class="inline-svg-wrapper">
	{{ svg('/plugins/vendor/plugin/assets/icon.svg') }}
</div>

Using variables

Aside from inlining the SVG itself the helper function will also pass any variables along to the SVG and parse it using October's Twig parser. This means you can easily create dynamic SVGs.

<!-- icon.svg -->
<svg fill="{{ fill }}" width="{{ width | default(800) }}"> ...

<!-- You can pass variables along as a second parameter -->
<img src="{{ svg('/plugins/xy/assets/icon.svg', {fill: '#f00', width: '200'}) }}">

Bug reports

It is very likely that there will be bugs with some specific html markup. If you encounter such a bug, please report it.

Future plans

Exclude/Include-Filters
Maybe a component to enable the middleware only on some pages

OFFLINE-GmbH / oc-responsive-images-plugin

ResponsiveImages Plugin for October CMS

Features