lrn-math/lrn-math.html at master · LRNWebComponents/lrn-math · GitHub

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<link rel="import" href="../polymer/polymer.html">
<link rel="import" href="../hax-body-behaviors/hax-body-behaviors.html">
<!--
`lrn-math`
A LRN element

@demo demo/index.html
-->

<dom-module id="lrn-math">
  <template>
    <style>
       :host {
        display: inline;
      }
    </style>
    [[prefix]] [[math]] [[suffix]]
    <span hidden><slot id="content"></slot></span>
  </template>

  <script>
    Polymer({
      is: 'lrn-math',
      behaviors: [
        HAXBehaviors.PropertiesBehaviors,
      ],
      properties: {
        /**
         * Styling for targeting the math pre and post
         */
        prefix: {
          type: String,
          value: '$$'
        },
        suffix: {
          type: String,
          value: '$$'
        },
        /**
         * display the math inline
         */
        inline: {
          type: Boolean,
          value: true,
          reflectToAttribute: true,
        },
        /**
         * The math to get rendered.
         */
        math: {
          type: String,
        },
        /**
         * backdown to inject text
         */
        mathText: {
          type: String,
          observer: '_mathChanged',
        }
      },
      observers: [
        '_inlineChanged(inline)',
      ],
      /**
       * Modify pre and suffix if inline is set
       */
      _inlineChanged: function(inline) {
        if (inline) {
          this.prefix = '\\(';
          this.suffix = '\\)';
        }
      },
      /**
       * Notice math changed, update slot.
       */
      _mathChanged: function(newValue, oldValue) {
        if (newValue !== oldValue) {
          while (Polymer.dom(this).firstChild !== null) {
            Polymer.dom(this).removeChild(Polymer.dom(this).firstChild);
          }
          let frag = document.createTextNode(newValue);
          Polymer.dom(this).appendChild(frag);
        }
      },
      /**
       * Attached life cycle
       */
      attached: function() {
        // Establish hax properties if they exist
        let props = {
          'canScale': true,
          'canPosition': true,
          'canEditSource': true,
          'gizmo': {
            'title': 'Math',
            'description': 'Present math in a nice looking way.',
            'icon': 'places:all-inclusive',
            'color': 'grey',
            'groups': ['Content'],
            'handles': [
              {
                'type': 'math',
                'math': 'mathText'
              },
              {
                'type': 'inline',
                'text': 'mathText'
              },
            ],
            'meta': {
              'author': 'LRNWebComponents'
            }
          },
          'settings': {
            'quick': [
              {
                'property': 'inline',
                'title': 'Inline',
                'description': 'Display this math inline',
                'inputMethod': 'boolean',
                'icon': 'remove',
              }
            ],
            'configure': [
              {
                'property': 'mathText',
                'title': 'Math',
                'description': 'Math',
                'inputMethod': 'textfield',
                'icon': 'editor:format-quote',
              },
              {
                'property': 'inline',
                'title': 'Inline',
                'description': 'Display this math inline',
                'inputMethod': 'boolean',
                'icon': 'remove',
              }
            ],
            'advanced': [
            ]
          }
        };
        this.setHaxProperties(props);
      },
      /**
       * Notice changes to the slot and reflect these to the math value
       * so that we can render it to the page.
       */
      ready: function () {
        if (typeof window.__mathJaxLoaded === typeof undefined) {
          let mathjaxCDN = document.createElement('script');
          mathjaxCDN.src = 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS_HTML';
          document.body.appendChild(mathjaxCDN);
          window.__mathJaxLoaded = true;
        }
        this._observer =
          Polymer.dom(this.$.content).observeNodes((info) => {
            this.math = info.addedNodes.map(node => node.textContent).toString();
            setTimeout(function() {
              MathJax.Hub.Queue(["Typeset", MathJax.Hub]);
            }, 100);
          });
      }
    });
  </script>
</dom-module>