SGH / COMPONENTS

<!--
@license
Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-->
<link rel="import" href="../marked-element/marked-element.html">
<link rel="import" href="../paper-styles/typography.html">
<link rel="import" href="../paper-styles/shadow.html">
<link rel="import" href="../paper-styles/color.html">
<link rel="import" href="../paper-button/paper-button.html">
<link rel="import" href="../polymer/polymer.html">
<link rel="import" href="../prism-element/prism-highlighter.html">

<link rel="import" href="iron-doc-property.html">

<!--
Renders documentation describing an element's API.

`iron-doc-viewer` renders element and behavior descriptions as extracted by
[Hydrolysis](https://github.com/PolymerLabs/hydrolysis). You can provide them
either via binding...

    <iron-doc-viewer descriptor="{{elementDescriptor}}"></iron-doc-viewer>

...or by placing the element descriptor in JSON as the text content of an
`iron-doc-viewer`:

    <iron-doc-viewer>
      {
        "is": "awesome-sauce",
        "properties": [
          {"name": "isAwesome", "type": "boolean", "desc": "Is it awesome?"},
        ]
      }
    </iron-doc-viewer>

However, be aware that due to current limitations in Polymer 0.8, _changes_ to
the text content will not be respected, only the initial value will be loaded.
If you wish to update the documented element, please set it via the `descriptor`
property.

@demo demo/index.html Basic Demo
-->
<dom-module id="iron-doc-viewer">

  <link rel="import" type="css" href="iron-doc-viewer.css">

  <template>
    <prism-highlighter></prism-highlighter>

    <section id="summary" class="card" hidden$="[[!descriptor.desc]]">
      <header>Documentation</header>
      <marked-element markdown="{{descriptor.desc}}">
        <div class="markdown-html"></div>
      </marked-element>
    </section>

    <nav id="api">
      <header>API Reference</header>
      <paper-button id="togglePrivate"
        on-tap="_togglePrivate">{{_privateToggleLabel}}</paper-button>
    </nav>

    <section id="properties" class="card" hidden$="{{_noneToShow(_showPrivate,_properties)}}">
      <header>Properties</header>
      <template is="dom-repeat" items="{{_properties}}" hidden$="{{!_properties.length}}">
        <iron-doc-property descriptor="{{item}}"></iron-doc-property>
      </template>
    </section>

    <section id="methods" class="card"  hidden$="{{_noneToShow(_showPrivate,_methods)}}">
      <header>Methods</header>
      <template is="dom-repeat" items="{{_methods}}">
        <iron-doc-property descriptor="{{item}}"></iron-doc-property>
      </template>
    </section>

    <section id="events" class="card" hidden$="{{_noneToShow(_showPrivate,_events)}}">
      <header>Events</header>
      <template is="dom-repeat" items="{{_events}}">
        <iron-doc-property descriptor="{{item}}"></iron-doc-property>
      </template>
    </section>

    <section id="behaviors" class="card" hidden$="{{_hideBehaviors(_behaviors)}}">
      <header>Behaviors</header>
      <template is="dom-repeat" items="{{_behaviors}}">
        <p on-click="_broadcastBehavior">{{item}}</p>
      </template>
    </section>

  </template>

</dom-module>

<script>
(function() {

  Polymer({

    is: 'iron-doc-viewer',

    properties: {

      /**
       * The [Hydrolysis](https://github.com/PolymerLabs/hydrolysis)-generated
       * element descriptor to display details for.
       *
       * Alternatively, the element descriptor can be provided as JSON via the text content
       * of this element.
       *
       * @type {hydrolysis.ElementDescriptor}
       */
      descriptor: {
        type: Object,
        observer: '_descriptorChanged',
      },

      /** Whether private properties should be hidden or shown. */
      _showPrivate: {
        type:     Boolean,
        value:    false,
        observer: '_showPrivateChanged',
      },

      /** The label to show for the Private API toggle. */
      _privateToggleLabel: String,

      /**
       * Broadcast when another component is clicked on
       * @param {String} detail name of the component
       * iron-doc-viewer container should load component if possible
       * @event iron-doc-viewer-component-selected
       */
    },

    ready: function() {
      var jsonDescriptor = this._loadJson();
      // Note that this is only an error during element creation. You are free
      // to stomp over the descriptor after it is ready.
      if (jsonDescriptor && this.descriptor) {
        console.error(
            this,
            'received both a bound descriptor:', this.descriptor,
            'and JSON descriptor:', this._jsonDescriptor,
            'Please provide only one');
        throw new Error(
            '<iron-doc-viewer> accepts either a bound or JSON descriptor; not both');
      }

      if (jsonDescriptor) {
        this.descriptor = jsonDescriptor;
      }
    },

    /**
     * Loads a hydrolysis element descriptor (as JSON) from the text content of
     * this element, if present.
     *
     * @return {hydrolysis.ElementDescriptor} The parsed descriptor, or `null`.
     */
    _loadJson: function() {
      var textContent = '';
      Array.prototype.forEach.call(Polymer.dom(this).childNodes, function(node) {
        textContent = textContent + node.textContent;
      });
      textContent = textContent.trim();
      if (textContent === '') return null;

      try {
        return JSON.parse(textContent);
      } catch(error) {
        console.error('Failure when parsing JSON:', textContent, error);
        throw error;
      }
    },

    /** Converts `descriptor` into our template-friendly `_model`. */
    _descriptorChanged: function() {
      if (!this.descriptor) return;

      // Split the documented properties between functions and other types.
      var properties = [];
      var methods    = [];

      for (var i = 0, property; property = this.descriptor.properties[i]; i++) {
        (property.type === 'Function' ? methods : properties).push(property);
      }
      this._properties = properties;
      this._methods    = methods;
      this._events     = this.descriptor.events || [];
      this._behaviors  = this.descriptor.behaviors || [];

      this.toggleAttribute('abstract', this.descriptor.abstract);
    },

    _collapsedChanged: function() {
      this._collapseToggleLabel = this._collapsed ? 'expand' : 'collapse';

      // Bound values aren't exposed to dom-repeat's scope.
      var properties = this.querySelectorAll('iron-doc-property');
      for (var i = 0, property; property = properties[i]; i++) {
        property.collapsed = this._collapsed;
      }
    },

    _toggleCollapsed: function() {
      this._collapsed = !this._collapsed;
    },

    _showPrivateChanged: function() {
      this._privateToggleLabel = (this._showPrivate ? 'hide' : 'show') + ' private API';
      this.toggleClass('show-private', this._showPrivate);
    },

    _togglePrivate: function() {
      this._showPrivate = !this._showPrivate;
    },

    _noneToShow: function(showPrivate, items) {
      for (var i = 0; i < items.length; i++) {
        if (showPrivate || !items[i].private) return false;
      }
      return true;
    },

    _hideBehaviors: function(behaviors) {
      return behaviors === null || behaviors.length === 0;
    },

    _broadcastBehavior: function(ev) {
      this.fire('iron-doc-viewer-component-selected', ev.target._templateInstance.item);
    }
  });

})();
</script>