Helpers or Utilities I used in Meteor.js project

helpers.coffee

# _.mixin
#   "eachSlice": (obj, size, iterator, context)->
#     for (i=0, l=obj.length; i < l; i+=size)
#       iterator.call(context, obj.slice(i,i+size), i, obj)


# http://stackoverflow.com/questions/10249658
`
Array.prototype.eachSlice = function (size, callback){
  for (var i = 0, l = this.length; i < l; i += size){
    callback.call(this, this.slice(i, i + size));
  }
};
`
# string.startsWith and endsWith
# http://stackoverflow.com/a/646643/166286
# http://stackoverflow.com/a/2548133
`
if (typeof String.prototype.startsWith != 'function') {
  String.prototype.startsWith = function (str){
    return this.slice(0, str.length) == str;
  };
}
if (typeof String.prototype.endsWith != 'function') {
  String.prototype.endsWith = function (str){
    return this.slice(-str.length) == str;
  };
}
`

spacebars.coffee

UI.registerHelper 'sessionGet', (input, subKey)->
  obj = Session.get(input)
  if obj? 
    return obj[subKey] 
  else 
    return obj

UI.registerHelper 'dateStr', (date)->
  return moment(date).format('L')

UI.registerHelper 'dateStrFull', (date)->
  return moment(date).format('MM/DD/YYYY LT')

UI.registerHelper 'acronymEmail', (email)->
  if email?
    return email.substring(0,2).toUpperCase()
  else
    return ''

UI.registerHelper 'rev', ->
  return 'rev ' + Meteor.settings.public.rev

# Utility

UI.registerHelper 'humanizeBoolean', (booleanValue)->
  if booleanValue 
    return 'Yes'
  else
    return 'No'

UI.registerHelper 'activeIf', (str1, str2)->
  if str1 == str2 then return 'active' else return ''

# HACK you cannot write array in template and use it in helper
# http://stackoverflow.com/questions/16783463/pass-array-written-in-template-to-meteor-handlebars-helper
# doens't work:
#   li(class="{{activeIf CurrentPathName ['tools', 'directDownload', 'essUsage'] }}")
UI.registerHelper 'activeIfStarts', (str1, str2)->
  if str1.startsWith str2 then return 'active' else return ''

UI.registerHelper 'ifThen', (cp1, cp2, strWhenTrue, strWhenFalse)->
  if cp1 == cp2 then return strWhenTrue else return strWhenFalse

UI.registerHelper 'idfy', (str)->
  return idEncode(str, '')

UI.registerHelper 'idfy', (str, str2, str3)->
  return idEncode(str+str2+str3, '') 

# get path name: 'debug', instead of '/debug'
UI.registerHelper 'currentPathName', ->
  current = Router.current()
  if current? then return current.route.name else return ''

# get the path: '/a/bc'
UI.registerHelper 'currentPath', ->
  current = Router.current()
  if current? then return current.path else return ''

UI events

// https://github.com/hharnisc/meteor-accounts-admin-ui-bootstrap-3/blob/bc613e55d4e8c9b419b798e92d274dc697d68b15/client/accounts_admin.js#L35

// search no more than 2 times per second
var setUserFilter = _.throttle(function(template) {
	var search = template.find(".search-input-filter").value;
	Session.set("userFilter", search);
}, 500);

Template.accountsAdmin.events({
	'keyup .search-input-filter': function(event, template) {
        setUserFilter(template);
        return false;
    },