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[MUSIC]

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[SOUND] Hi, Alena here,
to talk about templates.

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A template is a pattern used for
making accurate copies of something.

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A template engine is software designed
to combine templates with a data model

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to produce multiple pages that share
the same look throughout the site.

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These are the views in an MVC project.

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MVC stands for Model-View-Controller and

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is one of the most important design
patterns for organizing an application.

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The model represents the data
in your application.

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The view is the visual component
that presents the interface for

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users to interact with that data.

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The controller is responsible for
coordinating what specific actions

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need to be performed in order to return
the correct response for a user's request.

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For more information on
the MVC design pattern,

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check the notes associated
with this video.

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This course will be focusing
on the view portion of MVC,

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which is the visual component,
the templates of an application.

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Many people will tell you that
PHP itself is a template engine.

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Even if PHP started as
a template language,

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it has taken a much different direction.

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This isn't to say that PHP can't
be used as a template engine.

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In fact, there's a wonderful package
to help PHP to do just that.

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When creating an MVC application,
your views should be

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restricted to the display or
rendering of a page itself.

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The only logic that should be used is
a structure that directly relates to

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the display of the data, such as looping
over over a list to display each item,

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or deciding if something
should be shown or not.

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By keeping our code
organized in this fashion,

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we make it easier to add features and
fix bugs.

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We also make it easier for multiple
people to work together on a project

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while specializing in a specific
portion of the application.

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Using a templating language for
views restricts the available logic,

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while providing a clean and
simplified language,

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that makes these templates more
accessible for non-programmers as well.

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A template engine may also
provide greater security, and

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flexibility for your layouts,
by providing multiple inheritances,

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blocks, automatic output escaping,
and more.

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Instead of each individual view,
putting together the pieces it needs,

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such as the header and the footer, each
view can extend from a master template,

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and simply replace the portions
that need to be changed.

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There are many options when
choosing a template engine.

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This course will demonstrate
the use of Twig,

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one of the most common
template engines in PHP.

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Twig is built by the same people that
developed the Symphony framework.

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It provides a flexible, fast and
secure template engine,

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while being well documented.

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I'll be showing you how to use
Twig as a standalone package,

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while also sharing examples of
integrating with Frameworks.

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There isn't much difference
between these two approaches,

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because our views should be
kept as a separate concern.

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Let's get started setting up Twig for
our project.