handlebars.js/lib/handlebars/base.js

/*jshint eqnull: true */

module.exports.create = function() {

var Handlebars = {};

// BEGIN(BROWSER)

Handlebars.VERSION = "1.0.0";
Handlebars.COMPILER_REVISION = 4;

Handlebars.REVISION_CHANGES = {
  1: '<= 1.0.rc.2', // 1.0.rc.2 is actually rev2 but doesn't report it
  2: '== 1.0.0-rc.3',
  3: '== 1.0.0-rc.4',
  4: '>= 1.0.0'
};

Handlebars.helpers  = {};
Handlebars.partials = {};

var toString = Object.prototype.toString,
    functionType = '[object Function]',
    objectType = '[object Object]';

Handlebars.registerHelper = function(name, fn, inverse) {
  if (toString.call(name) === objectType) {
    if (inverse || fn) { throw new Handlebars.Exception('Arg not supported with multiple helpers'); }
    Handlebars.Utils.extend(this.helpers, name);
  } else {
    if (inverse) { fn.not = inverse; }
    this.helpers[name] = fn;
  }
};

Handlebars.registerPartial = function(name, str) {
  if (toString.call(name) === objectType) {
    Handlebars.Utils.extend(this.partials,  name);
  } else {
    this.partials[name] = str;
  }
};

Handlebars.registerHelper('helperMissing', function(arg) {
  if(arguments.length === 2) {
    return undefined;
  } else {
    throw new Error("Missing helper: '" + arg + "'");
  }
});

Handlebars.registerHelper('blockHelperMissing', function(context, options) {
  var inverse = options.inverse || function() {}, fn = options.fn;

  var type = toString.call(context);

  if(type === functionType) { context = context.call(this); }

  if(context === true) {
    return fn(this);
  } else if(context === false || context == null) {
    return inverse(this);
  } else if(type === "[object Array]") {
    if(context.length > 0) {
      return Handlebars.helpers.each(context, options);
    } else {
      return inverse(this);
    }
  } else {
    return fn(context);
  }
});

Handlebars.K = function() {};

Handlebars.createFrame = function(object) {
  var obj = {};
  Handlebars.Utils.extend(obj, object);
  return obj;
};

Handlebars.logger = {
  DEBUG: 0, INFO: 1, WARN: 2, ERROR: 3, level: 3,

  methodMap: {0: 'debug', 1: 'info', 2: 'warn', 3: 'error'},

  // can be overridden in the host environment
  log: function(level, obj) {
    if (Handlebars.logger.level <= level) {
      var method = Handlebars.logger.methodMap[level];
      if (typeof console !== 'undefined' && console[method]) {
        console[method].call(console, obj);
      }
    }
  }
};

Handlebars.log = function(level, obj) { Handlebars.logger.log(level, obj); };

Handlebars.registerHelper('each', function(context, options) {
  var fn = options.fn, inverse = options.inverse;
  var i = 0, ret = "", data;

  var type = toString.call(context);
  if(type === functionType) { context = context.call(this); }

  if (options.data) {
    data = Handlebars.createFrame(options.data);
  }

  if(context && typeof context === 'object') {
    if(context instanceof Array){
      for(var j = context.length; i<j; i++) {
        if (data) { data.index = i; }
        ret = ret + fn(context[i], { data: data });
      }
    } else {
      for(var key in context) {
        if(context.hasOwnProperty(key)) {
          if(data) { data.key = key; }
          ret = ret + fn(context[key], {data: data});
          i++;
        }
      }
    }
  }

  if(i === 0){
    ret = inverse(this);
  }

  return ret;
});

Handlebars.registerHelper('if', function(conditional, options) {
  var type = toString.call(conditional);
  if(type === functionType) { conditional = conditional.call(this); }

  if(Handlebars.Utils.isEmpty(conditional)) {
    return options.inverse(this);
  } else {
    return options.fn(this);
  }
});

Handlebars.registerHelper('unless', function(conditional, options) {
  return Handlebars.helpers['if'].call(this, conditional, {fn: options.inverse, inverse: options.fn});
});

Handlebars.registerHelper('with', function(context, options) {
  var type = toString.call(context);
  if(type === functionType) { context = context.call(this); }

  if (!Handlebars.Utils.isEmpty(context)) return options.fn(context);
});

Handlebars.registerHelper('log', function(context, options) {
  var level = options.data && options.data.level != null ? parseInt(options.data.level, 10) : 1;
  Handlebars.log(level, context);
});

// END(BROWSER)

return Handlebars;
};