MaterialComponent.js

import {h, Component} from 'preact';
import {MDCRipple} from '@material/ripple';

/**
 * Base class for every Material component in this package
 * NOTE: every component should add a ref by the name of `control` to its root dom for autoInit Properties
 *
 * @export
 * @class MaterialComponent
 * @extends {Component}
 */
export default class MaterialComponent extends Component {
  constructor() {
    super();
    // Attributes inside this array will be check for boolean value true
    // and will be converted to mdc classes
    this._mdcProps = [];
    // This will again be used to add apt classname to the component
    this.componentName = '';
    // The final class name given to the dom
    this.classText = '';
    // Shared setter for the root element ref
    this.setControlRef = control => {
      this.control = control;
    };
  }
  attachRipple() {
    if (this.props.ripple && this.control) {
      MDCRipple.attachTo(this.control);
    }
  }
  // Build the className based on component names and mdc props
  buildClassName() {
    // Class name based on component name
    this.classText = 'mdc-' + this.componentName;

    // Loop over mdcProps to turn them into classNames
    for (let propKey in this.props) {
      if (this.props.hasOwnProperty(propKey)) {
        const prop = this.props[propKey];
        if (typeof prop === 'boolean' && prop) {
          if (this._mdcProps.indexOf(propKey) !== -1) {
            this.classText += ' mdc-' + this.componentName + '--' + propKey;
          }
        }
      }
    }
  }

  getClassName(element) {
    if (!element) {
      return '';
    }
    const attrs = (element.attributes = element.attributes || {});
    let classText = this.classText;
    if (attrs.class) {
      classText += ' ' + attrs.class;
    }
    if (attrs.className && attrs.className !== attrs.class) {
      classText += ' ' + attrs.className;
    }
    return classText;
  }

  // Components must implement this method for their specific DOM structure
  materialDom(props) {
    return h('div', Object.assign({}, props), props.children);
  }

  render() {
    this.buildClassName();
    // Fetch a VNode
    const componentProps = this.props;
    const userDefinedClasses =
      componentProps.className || componentProps.class || '';
    // We delete class props and add them later in the final
    // step so every component does not need to handle user specified classes.
    if (componentProps['class']) delete componentProps['class'];
    if (componentProps['className']) delete componentProps['className'];

    const element = this.materialDom(componentProps);
    element.attributes = element.attributes || {};

    element.attributes.className = `${userDefinedClasses} ${this.getClassName(
      element
    )}`
      .split(' ')
      .filter(
        (value, index, self) => self.indexOf(value) === index && value !== ''
      ) // Unique + exclude empty class names
      .join(' ');
    // Clean this shit of proxy attributes
    this._mdcProps.forEach(prop => {
      delete element.attributes[prop];
    });
    return element;
  }
}