Web frameworks provide common web development functions like routing, forms, validation, database access, and testing to help developers follow principles of DRY (Don't Repeat Yourself) and DRE (Don't Repeat Everybody) coding. Frameworks separate core application concerns like the database and presentation for easier code reuse. While frameworks add server overhead, they promote best practices and allow focusing on the main task instead of reimplementing common functions.

1. Web Frameworks
code4lib SIG Spring Forum
March 16, 2011

2. SIG Co-conveners
Joanna DiPasquale, Columbia University Libraries
Kevin Reiss, CUNY Library Services
Yitzchak Schaffer, Touro College Libraries
@yitznewton

3. code4lib
http://code4lib.org/about
Grassroots library technology professional... collective
Especially interested in the development of open-source
software
Started in 2003 as email list
IRC: #code4lib on chat.freenode.net
Annual national conferences (Feb; next year in Seattle)
Regional ad hoc meetings (including this SIG)
Beer

4. Why frameworks?
DRY - don't repeat yourself
within your app
among your apps
DRE - don't repeat everybody
in the greater community
Architecture - separation of concerns

6. DRY / DRE
Chances are your app will require some or all of these:
Pretty URLs ( http://mylocalpl.org/news/basement-flooded-again )
Forms and validation
Input security
Database access → ORM
Unit testing
Somebody else did that already! Frameworks provide easy
ways to perform common web tasks.

7. Separation of concerns
Focus on the task at hand - separate out related but
different features
Easier to decouple and reuse code

8. <?
// posts.php
$db = DB::connect( $params );
$q = "SELECT * FROM post WHERE title='{$_GET['title']}'";
$result = $db->execute( $q );
?>
<ul>
<? while ($row = $db->fetch($result)): ?>
<li>
<a href="/show.php?id=<? echo $row->id ?>">
<? echo $row->title ?>
</a>
</li>
<? endwhile; ?>
</ul>
<? $db->close() ?>

9. <?
include header.inc;
$db = DB::connect( $params );
$q = "SELECT * FROM post WHERE title='{$_GET['title']}'";
$result = $db->execute( $q );
?>
<ul>
<? while ($row = $db->fetch($result)): ?>
<li>
<a href="/show.php?id=<? echo $row->id ?>">
<? echo $row->title ?>
</a>
</li>
<? endwhile; ?>
</ul>
<? $db->close() ?>

10. // post_controller.php
<?
$posts = ORM::table('post')
->findByTitle( $params['title'] );
?>
// post_view.php
<ul>
<? foreach ( $posts as $post ): ?>
<li>
<? echo link_to( $post->title,
'post/show?id='.$post->id ) ?>
</li>
<? endforeach; ?>
</ul>

11. Why not frameworks?
Server resources overhead (especially RAM)
Promote ignorance of low-level processes and attendant
issues (SQL injection, cross-site scripting attacks, etc.)