static.js 4.5 KB
Newer Older
Lab机器人's avatar
readme  
Lab机器人 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187
/**
 * Module dependencies
 */

var serialize = require('dom-serializer'),
    select = require('css-select'),
    parse = require('./parse'),
    _ = {
      merge: require('lodash.merge'),
      defaults: require('lodash.defaults')
    };

/**
 * $.load(str)
 */

exports.load = function(content, options) {
  var Cheerio = require('./cheerio');

  options = _.defaults(options || {}, Cheerio.prototype.options);

  var root = parse(content, options);

  var initialize = function(selector, context, r, opts) {
    if (!(this instanceof initialize)) {
      return new initialize(selector, context, r, opts);
    }
    opts = _.defaults(opts || {}, options);
    return Cheerio.call(this, selector, context, r || root, opts);
  };

  // Ensure that selections created by the "loaded" `initialize` function are
  // true Cheerio instances.
  initialize.prototype = Object.create(Cheerio.prototype);
  initialize.prototype.constructor = initialize;

  // Mimic jQuery's prototype alias for plugin authors.
  initialize.fn = initialize.prototype;

  // Keep a reference to the top-level scope so we can chain methods that implicitly
  // resolve selectors; e.g. $("<span>").(".bar"), which otherwise loses ._root
  initialize.prototype._originalRoot = root;

  // Add in the static methods
  _.merge(initialize, exports);

  // Add in the root
  initialize._root = root;
  // store options
  initialize._options = options;

  return initialize;
};

/*
* Helper function
*/

function render(that, dom, options) {
  if (!dom) {
    if (that._root && that._root.children) {
      dom = that._root.children;
    } else {
      return '';
    }
  } else if (typeof dom === 'string') {
    dom = select(dom, that._root, options);
  }

  return serialize(dom, options);
}

/**
 * $.html([selector | dom], [options])
 */

exports.html = function(dom, options) {
  var Cheerio = require('./cheerio');

  // be flexible about parameters, sometimes we call html(),
  // with options as only parameter
  // check dom argument for dom element specific properties
  // assume there is no 'length' or 'type' properties in the options object
  if (Object.prototype.toString.call(dom) === '[object Object]' && !options && !('length' in dom) && !('type' in dom))
  {
    options = dom;
    dom = undefined;
  }

  // sometimes $.html() used without preloading html
  // so fallback non existing options to the default ones
  options = _.defaults(options || {}, this._options, Cheerio.prototype.options);

  return render(this, dom, options);
};

/**
 * $.xml([selector | dom])
 */

exports.xml = function(dom) {
  var options = _.defaults({xmlMode: true}, this._options);

  return render(this, dom, options);
};

/**
 * $.text(dom)
 */

exports.text = function(elems) {
  if (!elems) {
    elems = this.root();
  }

  var ret = '',
      len = elems.length,
      elem;

  for (var i = 0; i < len; i++) {
    elem = elems[i];
    if (elem.type === 'text') ret += elem.data;
    else if (elem.children && elem.type !== 'comment') {
      ret += exports.text(elem.children);
    }
  }

  return ret;
};

/**
 * $.parseHTML(data [, context ] [, keepScripts ])
 * Parses a string into an array of DOM nodes. The `context` argument has no
 * meaning for Cheerio, but it is maintained for API compatibility with jQuery.
 */
exports.parseHTML = function(data, context, keepScripts) {
  var parsed;

  if (!data || typeof data !== 'string') {
    return null;
  }

  if (typeof context === 'boolean') {
    keepScripts = context;
  }

  parsed = this.load(data);
  if (!keepScripts) {
    parsed('script').remove();
  }

  // The `children` array is used by Cheerio internally to group elements that
  // share the same parents. When nodes created through `parseHTML` are
  // inserted into previously-existing DOM structures, they will be removed
  // from the `children` array. The results of `parseHTML` should remain
  // constant across these operations, so a shallow copy should be returned.
  return parsed.root()[0].children.slice();
};

/**
 * $.root()
 */
exports.root = function() {
  return this(this._root);
};

/**
 * $.contains()
 */
exports.contains = function(container, contained) {

  // According to the jQuery API, an element does not "contain" itself
  if (contained === container) {
    return false;
  }

  // Step up the descendants, stopping when the root element is reached
  // (signaled by `.parent` returning a reference to the same object)
  while (contained && contained !== contained.parent) {
    contained = contained.parent;
    if (contained === container) {
      return true;
    }
  }

  return false;
};