starplate/lib/parser.js

View engine built on incremental-dom

'use strict';

/**
 * Module dependencies.
 */

Object.defineProperty(exports, '__esModule', {
  value: true
});

var _createClass = (function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ('value' in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; })();

var _get = function get(_x, _x2, _x3) { var _again = true; _function: while (_again) { var object = _x, property = _x2, receiver = _x3; _again = false; if (object === null) object = Function.prototype; var desc = Object.getOwnPropertyDescriptor(object, property); if (desc === undefined) { var parent = Object.getPrototypeOf(object); if (parent === null) { return undefined; } else { _x = parent; _x2 = property; _x3 = receiver; _again = true; desc = parent = undefined; continue _function; } } else if ('value' in desc) { return desc.value; } else { var getter = desc.get; if (getter === undefined) { return undefined; } return getter.call(receiver); } } };

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { 'default': obj }; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError('Cannot call a class as a function'); } }

function _inherits(subClass, superClass) { if (typeof superClass !== 'function' && superClass !== null) { throw new TypeError('Super expression must either be null or a function, not ' + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

var _parse5 = require('parse5');

var _parse52 = _interopRequireDefault(_parse5);

var _incrementalDom = require('incremental-dom');

/**
 * Generates a random unique hex ID string.
 *
 * @private
 * @function
 * @name uid
 * @return {String}
 */

var uid = function uid(_) {
  return Math.abs(Math.random() * Date.now() | 1).toString('16');
};

/**
 * Ensures a function.
 *
 * @private
 * @function
 * @name ensureFunction
 * @param {Mixed} fn
 * @return {Function}
 */

var ensureFunction = function ensureFunction(fn) {
  return 'function' == typeof fn ? fn : function () {
    return void 0;
  };
};

/**
 * Parser class.
 *
 * @public
 * @class Parser
 * @extends parse5.Parser
 */

// Parser shared instance
var instance_ = null;

var Parser = (function (_parse5$Parser) {
  _inherits(Parser, _parse5$Parser);

  _createClass(Parser, null, [{
    key: 'sharedInstance',

    /**
     * Shared parser instance
     *
     * @public
     * @static
     * @method
     * @name sharedInstance
     * @return {Parser}
     */

    value: function sharedInstance() {
      instance_ = instance_ || new Parser();
      return instance_;
    }

    /**
     * Parser constructor.
     *
     * @public
     * @constructor
     */

  }]);

  function Parser() {
    _classCallCheck(this, Parser);

    _get(Object.getPrototypeOf(Parser.prototype), 'constructor', this).call(this, _parse52['default'].TreeAdapters.htmlparser2);

    /**
     * Known patches for this parser state.
     *
     * @public
     * @type {Map}
     * @name patches
     */

    this.patches = new Map();
  }

  /**
   * Creates a patch function used for updating
   * a given DOM Element from the provided source
   * HTML or DOM Element.
   *
   * @public
   * @method
   * @name createPatch
   * @param {String|Element} source
   * @return {Function} (domElement, [done]) => {Undefined}
   */

  _createClass(Parser, [{
    key: 'createPatch',
    value: function createPatch(source) {
      var html = source;

      // get cached patch if diff doesn't exist
      if (!this.hasPatch(source)) {
        return this.getPatch(source);
      }

      // consume source HTML if an element is given
      if (source instanceof HTMLElement) {
        html = source.innerHTML;
      }

      html = String(html).replace(/\n/g, ' ').replace(/\r/g, ' ');
      var root = this.parseFragment(html);
      var nodes = root.children;
      var stack = [];

      /**
       * Creates and pushes an instruction
       * to the render stack.
       *
       * @private
       * @function
       * @name createInstruction
       * @param {Function} fn
       */

      var createInstruction = function createInstruction(fn) {
        return stack.push(fn);
      };

      /**
       * Call each routine in stack.
       *
       * @private
       * @function
       * @name render
       */

      var render = function render(_) {
        return stack.forEach(function (routine) {
          return routine();
        });
      };

      /**
       * Patch routine for a given DOM Element.
       *
       * @public
       * @function
       * @param {Element} domElement
       * @param {Function} [done]
       */

      var partial = function partial(domElement, done) {
        done = ensureFunction(done);
        (0, _incrementalDom.patch)(domElement, function (_) {
          stack.forEach(function (routine) {
            return routine();
          });
          done();
        });
      };

      /**
       * Traverse node recursively appending
       * instructions to stack.
       *
       * @private
       * @function
       * @name traverse
       * @param {Object} node
       */

      function traverse(node) {
        var kv = [];
        var id = node.attribs ? node.attribs.id : uid();
        var attrs = node.attribs;
        var parent = node.parent;
        var hasChildren = Boolean(node.children ? node.children.length : 0);

        if (attrs && Object.keys(attrs).length) for (var key in attrs) {
          if (attrs[key]) kv.push(key, attrs[key]);
        }if ('tag' == node.type) {
          // begin node
          createInstruction(function (_) {
            return _incrementalDom.elementOpen.apply(undefined, [node.name, id, null].concat(kv));
          });

          // define child nodes
          if (hasChildren) node.children.forEach(traverse);

          // close node
          createInstruction(function (_) {
            return (0, _incrementalDom.elementClose)(node.name);
          });
        } else if ('text' == node.type && node.data) {
          // handle text nodes
          createInstruction(function (_) {
            return (0, _incrementalDom.text)(node.data);
          });
        } else if ('script' == node.type) {
          // skip script
        } else {
            // @TODO(werle) - what else ?
            throw new TypeError('Unhandled node type ' + node.type + '.');
          }
      };

      // Walk tree and generate
      // incremental DOM routines
      nodes.forEach(traverse);

      // set patch
      this.patches.set(source, partial);

      // provide partial patch function
      return partial;
    }

    /**
     * Predicate to determine if source given
     * is an already defined patch.
     *
     * @public
     * @method
     * @name hasPatch
     * @param {Mixed} source
     * @return {Boolean}
     */

  }, {
    key: 'hasPatch',
    value: function hasPatch(source) {
      return false == this.patches.has(source);
    }

    /**
     * Returns patch by source.
     *
     * @public
     * @method
     * @name getPatch
     * @param {Mixed} source
     * @return {Function}
     */

  }, {
    key: 'getPatch',
    value: function getPatch(source) {
      return this.patches.get(source) || null;
    }
  }]);

  return Parser;
})(_parse52['default'].Parser);

exports['default'] = Parser;
module.exports = exports['default'];