placeholder a qrcode.

1. Programmatic use API to process image: placeholder.getData(opts)

document.getElementById('img_holder').setAttribute('src', window.placeholder.getData(opts));

2. Image onerror event

onerror="this.src=placeholder.getData({size: '256x128', text: 'Image 404'})"

3. Use image config attribute.

<img class="placeholder" options="bgcolor=#2b5f07&text=%20&size=19x19">
<img options="size=256x128&text=Hello%2525%26%3DWorld" class="placeholder" options="bgcolor=#2b5f07&text=%20&size=19x19">
<img options="size=256x128&text=Hello!&bgcolor=#ccc&color=#969696&fstyle=oblique&fweight=bold&fsize=40&ffamily=consolas" class="placeholder" options="bgcolor=#2b5f07&text=%20&size=19x19">