RZA

Create simple HTML elements

const RZA = require('rza')
 
class MyElement extends RZA {
  get defaults () {
    // default render settings
    return { wrap: false }
  }
  async render (settings, innerHTML) {
    if (settings.wrap) {
      return `<span>${innerHTML}</span>`
    } else {
      return innerHTML
    }
  }
}
 
window.customElements.define('my-element', MyElement)

<!-- Example w/ defaults -->
<my-element>Test</my-element>
 
<!-- Renders -->
 
<my-element>
  <render>Test</render>
</my-element>
 
<!-- Example w/ property set -->
 
<my-element wrap>Test</my-element>
 
<!-- Renders -->
 
<my-element>
  <render>
    <span>Test</span>
  </render>
</my-element>
 
<!-- Setting properties dynamically cause re-rendering -->
 
<script>
  let elem = document.querySelector('my-element')
  elem.setAttribute('wrap', false)
  /* or we can just set element properties for the same thing */
  elem.wrap = false
  /* changing the element value ALSO triggers a rerender */
  elem.textContent = 'New Test'
</script> 
 
<!-- Triggers a Render, batched into a single render() call. -->
 
<my-element>
  <render>New Test</render>
</my-element>

See also: markdown-element.

render() function.

The render function you define will be called whenever relevant state (settings) are altered.

Returning a string will reset the innerHTML of the <render> element.

Returning the previous element value is a noop, RZA assumes that because you are returning the prior element you have manipulated it correctly.

Returning an HTML Element will append that element as a child and put it in the render slot of the shadowDOM so that it can be seen.

default types.

Setting an array for defaults defines those property names as settings but with no real defaults.

This means that element attributes and properties of these names will be treated as settings, and alterations to them will cause re-renders.

class MyElement extends RZA {
  get defaults () {
    return ['propname']
  }
}

Functions (sync and async) can be used as dynamic initializers for default properties.

class MyElement extends RZA {
  get defaults () {
    return { prop: async () => 'example' }
  }
}