alpaca/dist/lib/typeahead.js/src/common/utils.js

Alpaca provides the easiest and fastest way to generate interactive forms for the web and mobile devices. It runs simply as HTML5 or more elaborately using Bootstrap, jQuery Mobile or jQuery UI. Alpaca uses Handlebars to process JSON schema and provide

/*
 * typeahead.js
 * https://github.com/twitter/typeahead.js
 * Copyright 2013-2014 Twitter, Inc. and other contributors; Licensed MIT
 */

var _ = (function() {
  'use strict';

  return {
    isMsie: function() {
      // from https://github.com/ded/bowser/blob/master/bowser.js
      return (/(msie|trident)/i).test(navigator.userAgent) ?
        navigator.userAgent.match(/(msie |rv:)(\d+(.\d+)?)/i)[2] : false;
    },

    isBlankString: function(str) { return !str || /^\s*$/.test(str); },

    // http://stackoverflow.com/a/6969486
    escapeRegExChars: function(str) {
      return str.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&');
    },

    isString: function(obj) { return typeof obj === 'string'; },

    isNumber: function(obj) { return typeof obj === 'number'; },

    isArray: $.isArray,

    isFunction: $.isFunction,

    isObject: $.isPlainObject,

    isUndefined: function(obj) { return typeof obj === 'undefined'; },

    toStr: function toStr(s) {
      return (_.isUndefined(s) || s === null) ? '' : s + '';
    },

    bind: $.proxy,

    each: function(collection, cb) {
      // stupid argument order for jQuery.each
      $.each(collection, reverseArgs);

      function reverseArgs(index, value) { return cb(value, index); }
    },

    map: $.map,

    filter: $.grep,

    every: function(obj, test) {
      var result = true;

      if (!obj) { return result; }

      $.each(obj, function(key, val) {
        if (!(result = test.call(null, val, key, obj))) {
          return false;
        }
      });

      return !!result;
    },

    some: function(obj, test) {
      var result = false;

      if (!obj) { return result; }

      $.each(obj, function(key, val) {
        if (result = test.call(null, val, key, obj)) {
          return false;
        }
      });

      return !!result;
    },

    mixin: $.extend,

    getUniqueId: (function() {
      var counter = 0;
      return function() { return counter++; };
    })(),

    templatify: function templatify(obj) {
      return $.isFunction(obj) ? obj : template;

      function template() { return String(obj); }
    },

    defer: function(fn) { setTimeout(fn, 0); },

    debounce: function(func, wait, immediate) {
      var timeout, result;

      return function() {
        var context = this, args = arguments, later, callNow;

        later = function() {
          timeout = null;
          if (!immediate) { result = func.apply(context, args); }
        };

        callNow = immediate && !timeout;

        clearTimeout(timeout);
        timeout = setTimeout(later, wait);

        if (callNow) { result = func.apply(context, args); }

        return result;
      };
    },

    throttle: function(func, wait) {
      var context, args, timeout, result, previous, later;

      previous = 0;
      later = function() {
        previous = new Date();
        timeout = null;
        result = func.apply(context, args);
      };

      return function() {
        var now = new Date(),
            remaining = wait - (now - previous);

        context = this;
        args = arguments;

        if (remaining <= 0) {
          clearTimeout(timeout);
          timeout = null;
          previous = now;
          result = func.apply(context, args);
        }

        else if (!timeout) {
          timeout = setTimeout(later, remaining);
        }

        return result;
      };
    },

    noop: function() {}
  };
})();