Vue Visual
Vue 2 image and video loader supporting lazy loading. Visual 2.x is a simplification of Version 1.x with a greater reliance on modern browser features (IntersectionObserver, object-fit, srcset, sizes, etc).
Examples at https://bkwld.github.io/vue-visual.
Installation
- Install the package:
npm install --save vue-visual
or yarn add vue-visual
- Register the component:
import Vue from 'vue'
import Visual from 'vue-visual'
Vue.component('visual', Visual)
import 'vue-visual/index.css'
- These polyfills are recommended for older browsers:
Usage
See the Storybook.
Props
A list of the component properties that may be set on the Visual component.
Assets
-
image (string)
: The URL of an image to load.
-
srcset (string)
: An img
srcset, used in addition to the image
. Both are recommended.
-
webp-srcset (string)
: A srcset
that will be added to a source
inside of a picture
element with a type
of image/webp
.
-
video (string|array)
: A video that is loaded after the image is loaded if the device supports video. If a string, should be the URL to a source video. If an array, a list of video URLs that will be added as difference <source>
s.
Size
-
width (number|string)
: This width will be applied to the asset element. If a number, it's assumed to be a px value.
-
height (number|string)
: See width
-
max-width (number|string)
: This value will be applied to the asset element as the css max-width
. If a number, it's assumed to be a px value.
-
sizes (string)
: Specify the img
sizes
attribute.
-
aspect (number)
: Force the Visual to a specific aspect ratio. This works by making the asset position:absolute
and then using an inner div with a padding-top
set to a percentage.
-
expand (boolean)
: Make the Visual fill it's container via CSS using absolute positioning.
Style
-
object-fit (string)
- Default cover
. Like the CSS property.
-
object-position (string)
- Default center center
. Like the CSS property.
-
align (string)
- Default center middle
.. Used in conjunction with slots to position the slot content. May be any combination of one horizontal (left
, center
, right
) and one vertical (top
, middle
, bottom
) choice, space-delimited.
Loading
-
preload (boolean)
- Requires Nuxt framework. If true
will add <link rel="preload"/>
tags to the <head>
for the image assets.
-
autoload (boolean)
- Default: true
. If true
, assets are loaded immediately unless lazyload
.
-
lazyload (boolean)
- Waits until the Visual enters the viewport to trigger loading. Overrides autoload
.
-
intersection-options (object)
- IntersectionObserver options. Used with lazyload
and autopause
.
-
placeholder-color
- Sets a background color behind the assets. Most useful in conjunction with an aspect
value.
-
transition (string, boolean)
- Default: 'vv-fade'
. A Vue transition name that is applied when an asset is loaded. Set to an empty string to immediately render assets rather than waiting for loading.
Video
-
autoplay (boolean)
- If true
, begins playing immediately.
-
autopause (boolean)
- If true
, begins playing when the Visual enters the viewport and stops when it leaves. Overrides autoplay
.
-
loop (boolean)
- Sets <video>
loop
-
muted (boolean)
- Sets <video>
muted
-
controls (boolean)
- Sets <video>
controls
Accessibility
alt (string)
- Sets the alt
attribute or aria-label
value, depending on context.
Slots
default
: Markup is added after the assets and before the loaderimage-source
: Adds <source>
tags to the <picture>
element.video-source
: Adds <source>
tags to the <video>
element.
Methods
load()
- Manually initiate loading.play()
- Tell video
to play.pause()
- Tell video
to pause.restart()
- Tell video
to restart playback from beginning.
Events
loaded:image
- Image asset has finished loadingloaded:video
- Video asset has finished loadingloaded
- All assets hvae loaded
Contributing
- Boot up the Storybook with
yarn storybook
and use that as your HMR friendly dev environment - Use
npm version ...
to build, tag, and update the poblished storybook
Changes from 1.x
- Dropped props:
poster
fallback
- per-asset variants for
load
, etc
- Prop changes
background
➡ object-fit
background-position
➡ object-position
fill
➡ expand
- Not testing for video support on device
- Video playing state not stored in Vue state
- Image and video loaded simultenously, not in series
- Removed
setDefaults
for setting default options. See custom-defaults for an example of how to implement this functionality using a functional component.
migrate-1.x.coffee shows an example of a functional component that migrates the old API to the new API.