05s-the-session.md.erb

---
title: The Session
slug: the-session
date: 0005/01/02
number: 5.5
sidebar: true
contents: Learn about the Meteor Session|Learn about the autorun function|Learn about Hot Code Reload
paragraphs: 36
---

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### The Meteor Session

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### Changing the Session

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~~~js
❯ Session.set('pageTitle', 'A different title');
~~~
<%= caption "Browser console" %>

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~~~html
<header class="navbar navbar-default" role="navigation"> 
  <div class="navbar-header">
    <a class="navbar-brand" href="{{pathFor 'postsList'}}">{{pageTitle}}</a>
  </div>
</header>
~~~
<%= caption "client/templates/application/layout.html"%>

~~~js
Template.layout.helpers({
  pageTitle: function() { return Session.get('pageTitle'); }
});
~~~
<%= caption "client/templates/application/layout.js"%>

<% note do %>

### A Note About Sidebar Code

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<% end %>

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~~~js
❯ Session.set('pageTitle', 'A brand new title');
~~~
<%= caption "Browser console" %>

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<% note do %>

### Identical Changes

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<% end %>

### Introducing Autorun

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~~~js
helloWorld = function() {
  alert(Session.get('message'));
}
~~~

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~~~js
❯ Tracker.autorun( function() { console.log('Value is: ' + Session.get('pageTitle')); } );
Value is: A brand new title
~~~
<%= caption "Browser console" %>

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~~~js
❯ Session.set('pageTitle', 'Yet another value');
Value is: Yet another value
~~~
<%= caption "Browser console" %>

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~~~js
Tracker.autorun(function() {
  alert(Session.get('message'));
});
~~~

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### Hot Code Reload

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~~~js
❯ Session.set('pageTitle', 'A brand new title');
❯ Session.get('pageTitle');
'A brand new title'
~~~
<%= caption "Browser console" %>

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~~~js
❯ Session.get('pageTitle');
'A brand new title'
~~~
<%= caption "Browser console" %>

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~~~js
❯ Session.get('pageTitle');
null
~~~
<%= caption "Browser console" %>

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