Why would I get, "Uncaught TypeError: Cannot read property 'helpers' of undefined"?

Question

我在我的 Meteor 项目中得到了这个 html：

<head>
  <title>The Dentist Hurt My Fillings</title>
</head>

<body>
<h2>Thirteen Ways of Looking at a Duckbilled Platypus</h2>

<br/>
<br/>

<div class="container">
   {{> whizzardBlizzard}}
</div>

</body>

<template name="whizzardBlizzard">
    <form>
    {{#if firstStep}}
    {{> firstStepTemplate}}
    {{/if}}
    {{#if secondStep}}
    {{> secondStepTemplate}}
    {{/if}}
    {{#if thirdStep}}
    {{> thirdStepTemplate}}
    {{/if}}
    <input type="submit" value="Submit" class="button">
    </form>
</template>

<template name="firstStepTemplate">
  <h2>Step 1</h2>
</template>

<template name="secondStepTemplate">
  <h2>Step 2</h2>
</template>

<template name="thirdStepTemplate">
  <h2>Step 3</h2>
</template>

...还有这个 Javascript:

if (Meteor.isClient) {
  // stepNum starts at 1
  Session.setDefault('stepNum', 1);

  Template.whizzardBlizzard.events({
      "submit form": function (event) {
          //event.preventDefault();
          // save the vals to a new document in a collection
          Session.set('stepNum', Session.get('stepNum') + 1);
      }
  });

  Template.whizzardBlizard.helpers({
     'firstStep': function() {
         return (Session.get('stepNum') == 1);
     },
     'secondStep': function() {
         return (Session.get('stepNum') == 2)
     },
     'thirdStep': function() {
         return (Session.get('stepNum') == 3)
     }
     // . . .  etc.
  });

}

if (Meteor.isServer) {
  Meteor.startup(function () {
    // code to run on server at startup
  });
}

当我尝试运行时，我得到，"Uncaught TypeError: Cannot read property 'helpers' of undefined"?

怎么可能？模板助手是 Meteor 的一个关键组件，它的使用示例反映了我的。

我已经尝试过将帮助程序名称（例如 "firstStep"）用单引号引起来和不引起来；也就是说，我都试过了：

firstStep: function() {

..还有这个：

'firstStep': function() {

...这样称呼它时:

{{#if firstStep}}
    {{> firstStepTemplate}}
{{/if}}

那么为什么 'helpers' 据报道不可读？

Answer 1

Blizzard在你的助手中只有一个"z"：Blizard

Why would I get, "Uncaught TypeError: Cannot read property 'helpers' of undefined"?

Why would I get, "Uncaught TypeError: Cannot read property 'helpers' of undefined"?

javascript

meteor

meteor-blaze

meteor-helper