##<iron-image>
iron-image
is an element for displaying an image that provides useful sizing and
preloading options not found on the standard <img>
tag.
The sizing
option allows the image to be either cropped (cover
) or
letterboxed (contain
) to fill a fixed user-size placed on the element.
The preload
option prevents the browser from rendering the image until the
image is fully loaded. In the interim, either the element's CSS background-color
can be be used as the placeholder, or the placeholder
property can be
set to a URL (preferably a data-URI, for instant rendering) for an
placeholder image.
The fade
option (only valid when preload
is set) will cause the placeholder
image/color to be faded out once the image is rendered.
Examples:
Basically identical to <img src="...">
tag:
<iron-image src="http://lorempixel.com/400/400"></iron-image>
Will letterbox the image to fit:
<iron-image style="width:400px; height:400px;" sizing="contain"
src="http://lorempixel.com/600/400"></iron-image>
Will crop the image to fit:
<iron-image style="width:400px; height:400px;" sizing="cover"
src="http://lorempixel.com/600/400"></iron-image>
Will show light-gray background until the image loads:
<iron-image style="width:400px; height:400px; background-color: lightgray;"
sizing="cover" preload src="http://lorempixel.com/600/400"></iron-image>
Will show a base-64 encoded placeholder image until the image loads:
<iron-image style="width:400px; height:400px;" placeholder="data:image/gif;base64,..."
sizing="cover" preload src="http://lorempixel.com/600/400"></iron-image>
Will fade the light-gray background out once the image is loaded:
<iron-image style="width:400px; height:400px; background-color: lightgray;"
sizing="cover" preload fade src="http://lorempixel.com/600/400"></iron-image>
Custom property | Description | Default |
---|---|---|
--iron-image-placeholder |
Mixin applied to #placeholder | {} |
--iron-image-width |
Sets the width of the wrapped image | auto |
--iron-image-height |
Sets the height of the wrapped image | auto |