README

This Twig extension facilitates the integration of responsive images markup in Twig templates.

It uses LiipImagineBundle and its filters to generate HTML markup with all you need to handle responsive images.

It also provides a JavaScript module to automatically instantiate yall.js on rendered images.

Installation

Use the package manager composer to install the extension.

composer require umanit/twig-image-extension

Load the bundle into your Symfony project.

<?php

# config/bundles.php
return [
    // ...
    Umanit\TwigImage\UmanitTwigImageBundle::class => ['all' => true],
];

(Optional) Install bundle assets if you want to use the javascript module for yall.js:

bin/console assets:install --symlink

Configuration

umanit_twig_image:
    allow_fallback: false
    use_liip_default_image: false
    class_selector: lazy
    placeholder_class_selector: lazy-placeholder
    blur_class_selector: lazy-blur

Some functions render HTML markup with the ability to use lazy loading on images. It's possible to customize the classes used with the 3 options class_selector, placeholder_class_selector and blur_class_selector.

Fallback images

By default, if the image path given in functions calls is null, empty or points to a missing file on the server, an exception is thrown. You have two options to avoid this:

setting twig_image_extension.allow_fallback to true
setting twig_image_extension.use_liip_default_image to true

`twig_image_extension.allow_fallback`

If the path given points to a missing file, a default image will be rendered instead. The default images are available in four sizes:

small: 320px wide
medium: 640 wide
large: 1280px wide
extra large: 2560px wide (for Retina screens mostly)

If a default image needs to be rendered, the size will be guessed using the given Liip filter:

a filter ending with 2x will give you an extra large default image
a filter ending with xl or xxl will give you a large default image
a filter ending with xs or xxs will give you a small default image
any other filter name will default to the medium size

`twig_image_extension.use_liip_default_image`

This parameter will only be used as a backup if allow_fallback is set to false and requires you to use the default image mecanism of Liip ( see Liip configuration)

Usage

The following Twig functions are available in your templates.

umanit_image_figure_lazy_load
umanit_image_figure
umanit_image_picture_lazy_load
umanit_image_picture
umanit_image_img
umanit_image_srcset
(Optional) Javascript module to instantiate yall.js
(Optional) Import CSS files for blur effect on yall.js lazy images

When a LiipImagine filter is used, the extension will read its configuration and automatically guess the right width or height to apply in the markup. If it's not possible, the extension will try to get the original image dimensions instead. In both case, the result is saved in cache to avoid multiple process for the same image.

When the used function is for lazy load, lazy and lazy-placeholder classes are used but can be customized as explained in the Configuration part.

width and height attributes are added in the <img /> tag, based on the size calculated by the src filter (except for downscale and upscale filters, which fallback to the original image size). By doing this, sudden layout shifts are avoided for a better user experience.

To use htmlAlt, the css file umanit-alt-text.css must be loaded. It hides the div used to display the html alt content.

umanit_image_figure_lazy_load

Generates a figure tag with an img inside and his noscript version. The lazy, lazy-placeholder and lazy-blur classes are add to facilitate the integration with yall.js for example.

Parameters

Example

Click to show

Without htmlAlt

    umanit_image_figure_lazy_load(
      image.path,
      'small_thumbnail',
      'tiny_thumbnail',
      ['thumbnail', 'large_thumbnail'],
      'image alt',
      'img img--cover img--zoom',
      '(min-width: 768px) 33.3vw, 100vw',
      'class-figure',
      'Figcaption text',
      'class-figcaption',
      'high',
      'data-container="a"',
      'data-image="b" data-test'
    )

HTML generated:

<figure class="class-figure" data-container="a">
<img
    alt="image alt"
    class="lazy lazy-placeholder lazy-blur img img--cover img--zoom"
    src="https://domain.tld/media/cache/tiny_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    data-src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    sizes="(min-width: 768px) 33.3vw, 100vw"
    data-srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
    importance="high"
    data-image="b" data-test
>
<noscript>
  <img
      class="img img--cover img--zoom"
      alt="home"
      src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
      sizes="(min-width: 768px) 33.3vw, 100vw"
      srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
      width="600" height="400"
      importance="high"
      data-image="b" data-test
  >
</noscript>
<figcaption class="class-figcaption">Figcaption text</figcaption>
</figure>

With htmlAlt

    umanit_image_figure_lazy_load(
      image.path,
      'small_thumbnail',
      'tiny_thumbnail',
      ['thumbnail', 'large_thumbnail'],
      'image alt',
      'img img--cover img--zoom',
      '(min-width: 768px) 33.3vw, 100vw',
      'class-figure',
      'Figcaption text',
      'class-figcaption',
      '<p>Html to describe content</p>'
    )

HTML generated

<figure class="class-figure">
<img
    alt=""
    aria-describedby="1234567890"
    class="lazy lazy-placeholder lazy-blur img img--cover img--zoom"
    src="https://domain.tld/media/cache/tiny_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    data-src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    sizes="(min-width: 768px) 33.3vw, 100vw"
    data-srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
>
<noscript>
  <img
      class="img img--cover img--zoom"
      alt=""
      aria-describedby="1234567890"
      src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
      sizes="(min-width: 768px) 33.3vw, 100vw"
      srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
      width="600" height="400"
  >
</noscript>
<figcaption class="class-figcaption">Figcaption text</figcaption>
</figure>
<div id="1234567890"><p>Html to describe content</p></div>

The id used for aria-describedby is a random dynamically generated value.

umanit_image_figure

Generates a figure tag with an img inside.

Parameters

Example

Click to show

Without htmlAlt

    umanit_image_figure(
      image.path,
      'small_thumbnail',
      ['thumbnail', 'large_thumbnail'],
      'image alt',
      'img img--cover img--zoom',
      '(min-width: 768px) 33.3vw, 100vw',
      'class-figure',
      'Figcaption text',
      'class-figcaption',
      'low',
      'data-container="a"',
      'data-image="b" data-test'
    )

HTML generated:

<figure class="class-figure" data-container="a">
<img
    alt="image alt"
    class="img img--cover img--zoom"
    src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    sizes="(min-width: 768px) 33.3vw, 100vw"
    srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
    importance="low"
    importance="high"
    data-image="b" data-test
>
<figcaption class="class-figcaption">Figcaption text</figcaption>
</figure>

With htmlAlt

     umanit_image_figure(
       image.path,
       'small_thumbnail',
       ['thumbnail', 'large_thumbnail'],
       'image alt',
       'img img--cover img--zoom',
       '(min-width: 768px) 33.3vw, 100vw',
       'class-figure',
       'Figcaption text',
       'class-figcaption',
       '<p>Html to describe content</p>'
     )

HTML generated

<figure class="class-figure">
<img
    alt=""
    aria-describedby="1234567890"
    class="lazy lazy-placeholder lazy-blur img img--cover img--zoom"
    src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    sizes="(min-width: 768px) 33.3vw, 100vw"
    srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
>
<figcaption class="class-figcaption">Figcaption text</figcaption>
</figure>
<div id="1234567890"><p>Html to describe content</p></div>

The id used for aria-describedby is a random dynamically generated value.

umanit_image_picture_lazy_load

Generates a picture tag with an img inside and X source. Each source can have a media and sizes attribute if needed. The lazy and lazy-placeholder classes are add to facilitate the integration with yall.js for example.

Parameters

Example

Click to show

Without htmlAlt

  umanit_image_picture_lazy_load(
    image.path,
    'small_thumbnail',
    'tiny_thumbnail',
    ['thumbnail', 'large_thumbnail'],
    {
      (image.path): {
        'media': '(min-width: 768px)',
        'sizes': '(min-width: 1400px) 25vw, 50vw',
        'filters': ['thumbnail', 'large_thumbnail']
      },
      (image2.path): ['thumbnail', 'large_thumbnail']
    },
    'alt img',
    'img img-fluid',
    'class-picture',
    'high',
    'data-picture data-markup="c"',
    'data-image="d"
  )

HTML generated

<picture class="class-picture" data-picture data-markup="c">
<source media="(min-width: 768px)" sizes="(min-width: 1400px) 25vw, 50vw" srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w" width="600" height="400">
<source srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w" width="300" height="200">
<img
    class="img img-fluid"
    alt="alt img"
    src="https://domain.tld/media/cache/tiny_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    data-src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    data-srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
    importance="high"
    data-image="d"
>
</picture>

With htmlAlt

  umanit_image_picture_lazy_load(
    image.path,
    'small_thumbnail',
    'tiny_thumbnail',
    ['thumbnail', 'large_thumbnail'],
    {
      (image.path): {
        'media': '(min-width: 768px)',
        'sizes': '(min-width: 1400px) 25vw, 50vw',
        'filters': ['thumbnail', 'large_thumbnail']
      },
      (image2.path): ['thumbnail', 'large_thumbnail']
    },
    'alt img',
    'img img-fluid',
    'class-picture',
    '<p>Html to describe content</p>'
  )

HTML generated

<picture class="class-picture">
<source media="(min-width: 768px)" sizes="(min-width: 1400px) 25vw, 50vw" srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w" width="600" height="400">
<source srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg2 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg2 2880w" width="300" height="200">
<img
    class="img img-fluid"
    alt=""
    aria-describedby="1234567890"
    src="https://domain.tld/media/cache/tiny_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    data-src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    data-srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
>
</picture>
<div id="1234567890"><p>Html to describe content</p></div>

The id used for aria-describedby is a random dynamically generated value.

umanit_image_picture

Generates a picture tag with an img inside and X source. Each source can have a media and sizes attribute if needed.

Parameters

Example

Click to show

Without htmlAlt

  umanit_image_picture(
    image.path,
    'small_thumbnail',
    ['thumbnail', 'large_thumbnail'],
    {
      (image.path): {
        'media': '(min-width: 768px)',
        'sizes': '(min-width: 1400px) 25vw, 50vw',
        'filters': ['thumbnail', 'large_thumbnail']
      },
      (image2.path): ['thumbnail', 'large_thumbnail']
    },
    'alt img',
    'img img-fluid',
    'class-picture',
    'low',
    'data-picture data-markup="c"',
    'data-image="d"
  )

HTML generated

<picture class="class-picture" data-picture data-markup="c">
<source media="(min-width: 768px)" sizes="(min-width: 1400px) 25vw, 50vw" srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w" width="600" height="400">
<source srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w" width="300" height="200">
<img
    class="img img-fluid"
    alt="alt img"
    src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
    importance="low"
    data-image="d"
>
</picture>

With htmlAlt

  umanit_image_picture(
    image.path,
    'small_thumbnail',
    ['thumbnail', 'large_thumbnail'],
    {
      (image.path): {
        'media': '(min-width: 768px)',
        'sizes': '(min-width: 1400px) 25vw, 50vw',
        'filters': ['thumbnail', 'large_thumbnail']
      },
      (image2.path): ['thumbnail', 'large_thumbnail']
    },
    'alt img',
    'img img-fluid',
    'class-picture',
    '<p>Html to describe content</p>'
  )

HTML generated

<picture class="class-picture">
<source media="(min-width: 768px)" sizes="(min-width: 1400px) 25vw, 50vw" srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w" width="600" height="400">
<source srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg2 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg2 2880w" width="300" height="200">
<img
    class="img img-fluid"
    alt=""
    aria-describedby="1234567890"
    src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
    srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
    width="600" height="400"
>
</picture>
<div id="1234567890"><p>Html to describe content</p></div>

umanit_image_img

Generates an img tag.

Parameters

Example

Click to show

    umanit_image_img(
      image.path,
      'small_thumbnail',
      ['thumbnail', 'large_thumbnail'],
      'image alt',
      'img img--cover img--zoom',
      '(min-width: 768px) 33.3vw, 100vw',
      'low',
      'data-image="b" data-test'
    )

HTML generated:

<img
  alt="image alt"
  class="img img--cover img--zoom"
  src="https://domain.tld/media/cache/resolve/small_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg"
  sizes="(min-width: 768px) 33.3vw, 100vw"
  srcset="https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w"
  width="600" height="400"
  importance="low"
  data-image="b" data-test
>

umanit_image_srcset

Generates the content of a srcset attribute if you wan to use it in your own markup.

Parameters

Example

Click to show

umanit_image_srcset(image.path, ['thumbnail', 'large_thumbnail'])

HTML generated

https://domain.tld/media/cache/resolve/thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 260w, https://domain.tld/media/cache/resolve/large_thumbnail/99/30/c1f268bbf1487fb88734f2ba826b.jpeg 2880w

(Optional) Javascript module to instantiate yall.js

If you want to use yall.js to manage the lazy load of your images, the bundle provides a javascript module that can be called in your application.

yall.js needs to be installed manually: yarn add yall-js

Then you need to import the module and instantiate it by passing the yall library. An optional argument loadEventCallback is available if you want to add more customization. It will be called in the load event of yall.js.

import yall from 'yall-js';
import umanitImageLazyLoad from '../../public/bundles/umanittwigimage/js/umanit-image-lazy-loading';

umanitImageLazyLoad(yall);

(Optional) Import CSS files for blur effect on yall.js lazy images

You can import the CSS file for adding a blur effect on lazy images.

<link rel="stylesheet" href="{{ asset('css/umanit-image-lazy-loading.css', 'twig_image_bundle') }}">

Example in webpack

import '../../public/bundles/umanittwigimage/css/umanit-image-lazy-loading.css';

⚠ For a best usage for the users without javascript you should add a no-js class on the html element

<html class="no-js">

Finally, add this one line <script> before any <link> or <style> elements in the document <head>

<!-- Remove the no-js class on the <html> element if JavaScript is on -->
<script>document.documentElement.classList.remove("no-js");</script>

See https://github.com/malchata/yall.js/#what-about-users-without-javascript for more details.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

License

MIT

umanit / twig-image-extension

Maintainers

Details

README

Installation

Configuration

Fallback images

`twig_image_extension.allow_fallback`

`twig_image_extension.use_liip_default_image`

Usage

umanit_image_figure_lazy_load

Parameters

Example

Without htmlAlt

With htmlAlt

umanit_image_figure

Parameters

Example

Without htmlAlt

With htmlAlt

umanit_image_picture_lazy_load

Parameters

Example

Without htmlAlt

With htmlAlt

umanit_image_picture

Parameters

Example

Without htmlAlt

With htmlAlt

umanit_image_img

Parameters

Example

umanit_image_srcset

Parameters

Example

(Optional) Javascript module to instantiate yall.js

(Optional) Import CSS files for blur effect on yall.js lazy images

Contributing

License