lenye_base/loadjs.js

基础方法

'use strict';

require('./get_tag.js');
var is_function = require('./is_function.js');
var is_string = require('./is_string.js');
require('./ifnodeorbrowser.js');
require('./windowsimulate.js');
var ua = require('./ua.js');
var attr = require('./attr.js');
var c = require('./c.js');
var hash = require('./hash.js');

/* eslint-disable no-invalid-this */
/**
 * load js
 * 1. bbo.loadjs("//your_url/a.js",func);
 * 2. bbo.loadjs("//your_url/a.js","only_id",func);
 */

var _cache = {
  urls: {},
  logs: {}
};

var _insertScripts = function (arr, callback) {
  for (var i = 0; i < arr.length; i++) {
    _insertScript(arr[i], loaded);
  }

  var _index = 0;

  function loaded() {
    _index++;

    if (_index >= arr.length) {
      callback && callback();
    }
  }
};

var _insertScript = function (src, callback) {
  var script = c('script');
  attr(script, 'type', 'text/javascript');
  attr(script, 'src', src);
  attr(script, 'charset', 'utf-8');
  document.getElementsByTagName('head')[0].appendChild(script);

  if (/msie/.test(ua('l'))) {
    script.onreadystatechange = function () {
      if (this.readyState === 'loaded' || this.readyState === 'complete') {
        callback();
      }
    };
  } else if (/gecko/.test(ua('l'))) {
    script.onload = function () {
      callback();
    };
  } else {
    setTimeout(function () {
      callback();
    }, 50);
  }
};

function loadjs(url, b, c) {
  var onlyId;
  var callback;

  if (is_function(b)) {
    onlyId = String(hash(String(url)));
    callback = b;
  } else if (typeof b === 'undefined') {
    onlyId = String(hash(String(url)));
    callback = null;
  } else {
    onlyId = String(b);
    callback = c;
  }

  if (_cache.urls[onlyId]) {
    callback && callback();
  } else {
    var func = is_string(url) ? _insertScript : _insertScripts;
    func.call(this, url, function () {
      _cache.urls[onlyId] = true;
      callback && callback();
    });
  }
}

module.exports = loadjs;