Bag of tricks
from
iusethis.com

6. Who's behind iusethis?
Is it a corporate thingie?
Nah. Iusethis was made
by Arne and Marcus. We're
just these guys, you know?
But we really know where
our towels are.

Social
Software
For Software

Status after 1 year
• 15.000 registered users
• 4.000 registered apps
• ~ 250.000 page views per day
• 20.000 revisions committed to
SVN

Catalyst made such
rapid development
possible

While still
keeping it
sane to
maintain

Design Philosophies

Design Philosophies
• URLs matter!

Design Philosophies
• URLs matter!
• AJAX when it makes sense

Design Philosophies
• URLs matter!
• AJAX when it makes sense
• Support standards

Design Philosophies
• URLs matter!
• AJAX when it makes sense
• Support standards
• Provide alternative
data-formats

Design Philosophies
• URLs matter!
• AJAX when it makes sense
• Support standards
• Provide alternative
data-formats
• The user owns his data

AJAX

AJAH

AJAH
XMLHTTPRequest and DIV filling

Enhance
Not Replace

Example:
<span><a href=\"\" onclick=
\"CallBmk(); return false;\"
>Bookmark this</a></span>

NO!

Lynx Friendly First:
<a href=”/do_some_shit”
id=”do_some_shit”/>

Meanwhile...
<script type=”text/javascript”>
$(‘do_some_shit’).onclick=function()
{
// Fill that div good!
return false;
}// /do_some_shit is never called
</script>

Side note:
<a href=”/do_some_shit”
id=”do_some_shit”/>
<a href=”[%c.uri_for(‘/
do_some_shit’)%]”
id=”do_some_shit”/>

Ditto for Forms
<form action=”[%c.uri_for(‘/doit’)%]”
id=”doit”/>
<script type=”text/javascript”>
$(‘doit’).onsubmit=function() {
// Do something neat with the form
return false;
} // form is never submitted
</script>

Server side Validation
without submit

<script type=”text/javascript”>
$(‘register_screenname’).onchange =
function() {
var screenname=”name=”+
$(‘register_screenname’).value
var updater=new Ajax.Updater(
‘register_screenname_errors’,
‘[%c.uri_for(‘/jsrpc/
user_name_available’)%]’,
{parameters: screenname });
}
</script>
iusethis forms are generated by HTML::Widget -
lots of hooks through classes/ids

And in the
Controller:

sub user_name_available : Local {
my ($self,$c) = @_;
if ($c->model('DB::Person')
->search({
screenname => $c->req->param('name')
})->count()) {
$c->res->body('<span>'.
$c->req->param('name').
' is already registered</span>');
} else {
$c->res->body(' ');
}
}

Case Study:
iusethis counter

<div class=”iusethis”>
<div id=”iuse_[%app.short%]” class=”count”>
[%app.count%]</div>
<a id=”mark_[%app.id%]” href=\"[%c.uri_for
('/app/iusethis',
app.id,secret,c.user.obj.screenname)%]\"
title=\"Mark as used\">i use this</a></div>
<script type=”text/javascript”>
$(‘mark_[%app.id%]’).onclick=function() {
new Ajax.Updater('iuse_[%app.short%]',
'[%c.uri_for('/app/iusethis',
app.id,secret,c.user.obj.screenname)%]',
{evalScripts:true,method:'post',
postBody:'count=[%use_count%]'});
return false;
}
</script>

Inline
Javascript

Behaviour.js
Cleaner - But slower

Meanwhile, in
the controller...

sub iusethis : Local {
my ($self,$c,$id,$secret,$screenname) = @_;
my $app:Stashed = $c->model('DB::Application')
->find($id);
$c->stash->{app}->add_to_iuses(
{person=>$c->user_object});
$c->forward('app',[$app->short])
unless( $c->req->header('x-requested-with') &&
$c->req->header('x-requested-with') eq
'XMLHttpRequest');
# otherwise render ajax template
}

$secret ?
Protect against abuse
Catalyst::Plugin::RequestToken

Let’s look at
a variant

Email Validation
sub confirm_email : Private {
my ($self,$c,$user) = @_;
my $item:Stashed=$user;
my $seed:Stashed= md5_hex(
$user->registered.$c->config->{seed});
$c->email(
header => [
From => $c->config->{system_mail},
To => $user->email,
Subject => 'iusethis email
confirmation.'
],
body => $c->view('TT')->render
($c,'mailwelcome.tt'),
);
my $template:Stashed='validate.tt';

RSS

sub hot_xml : Path('/hot.rss') {
my ($self,$c) = @_;
my $feed:Stashed;
$c->forward('hot');
$c->forward('rss');
$feed->title(
'Hot apps from iusethis.com');
$feed->link(
$c->uri_for('/hot'));
$c->res->body($feed->as_xml);
}

sub rss : Private {
my ($self,$c) = @_;
my $feed:Stashed=
XML::Feed->new('RSS');
$feed->link($c->uri_for('/'));
$feed->tagline(
'i use this. What do you use?');
my $app:Stashed;
if ($apps) {
while( my $app = $apps->next ) {
.... # New entry
}
}
}

Another alternative
rss.tt:
<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<rss version=\"2.0\"
xmlns:iusethis=\"http://osx.iusethis.com/
ns/rss\" xmlns:dc=\"http://purl.org/dc/
elements/1.1/\">
<channel>
<title>[% title || 'RSS Feed from
iusethis.com '%]</title>
.....

Autodiscovery
header.tt:
[% IF rss %]
<link rel=\"alternate\" title=\"Iusethis RSS\"
href=\"[%rss%]\" type=\"application/rss+xml\"/>
[% END %]

Authentication

DBIC Auth
Plugins:
Authentication
Authentication::Store::DBIC
Authentication::Credential::Password
config:
authentication:
dbic:
user_class: DBIC::Person
password_field: password
user_field:
- screenname
- email

And in the
Controller:

if ($c->req->param('email')) {
if ( $c->login($c->req->param('email'),$c->req->param
('pass')) ) {
my $root=$c->uri_for('/');
delete $c->req->params->{referer}
if $c->req->params->{referer} eq $root ||
$c->req->params->{referer} !~ m/^$root/ ||
$c->req->params->{referer} eq $root.\"logout\";
$c->res->redirect( $c->req->params->{referer} ||
$c->uri_for('/user',$c->user->obj->screenname));
if ($c->req->param('openid')) {
$c->user->obj->openid($c->req->param('openid'));
$c->user->obj->update();
}
} else {
my $alert:Stashed='Login failed';
}

Basic Auth
Plugins:
Authentication::Credential::HTTP
config:
authentication:
http:
type: basic

And in the
Controller:

sub auto : Private {
my ( $self, $c ) = @_;
return 1 if $c->action eq 'api/index';
$c->authorization_required( realm =>
\"iusethis\" );
unless ($c->req->method eq 'POST') {
$c->res->body('API Requests require
HTTP POST');
return 0;
}
return 1;
}

OpenID
Plugins:
Authentication::Credential::OpenID

And in the
Controller:

if ($c->authenticate_openid) {
if (my $person=$c->model('DBIC::Person')
->find({openid=>$c->user->url})) {
my $user=$c->get_user($person->screenname)
|| die \"Could not make user object for \" .
$person->screenname.\"\\n\";
$c->set_authenticated($user);
return $c->res->redirect(
$c->uri_for('/user',$person->screenname));
}
my $openid:Stashed=$c->user->url;
$c->logout;
}
elsif (! @{$c->error}) {
return if $c->res->redirect;
$c->res->redirect($c->uri_for(
'/login',{openid_failed=>1}));
}
};

OPML
Outline Processor Markup
Language -- is an XML
format for outlines.

sub user_opml : Global {
my ($self,$c,$screenname)= @_;
my $user=$c->model('DBIC::Person')
->search({
screenname=>$screenname})->first;
my $opml=XML::OPML::SimpleGen->new();
$opml->head(title
=>'Apps used by '.$user->screenname);
my $apps=$user->applications;
...

while (my $app=$apps->next) {
$opml->add_outline(
text => $app->name,
count => $app->iuses->count,
icon => $app->has_icon($c) ?
$app->icon_uri($c) :
$c->uri_for_img('default.png')
->as_string,
xmlUrl => $c->uri_for('/appcast',$app->short)
->as_string,
group => $app->uses_this($user)
->iloveit ? 'loved' : 'apps',
);
}
$c->res->body($opml->as_string);
$c->res->content_type('text/xml');
}

Tags

CREATE TABLE tag (
id INTEGER PRIMARY KEY,
name TEXT,
application INT
REFERENCES application
);

Aggregating
popular tags

sub aggregated : ResultSet {
return scalar shift->search({'me.name',
{ -not_in => [ @banned_tags ]}}, {
select=>[{count => 'id'},'name' ],
as=>[qw/tagcount name/],
group_by=>[qw/name/],
order_by=>\"count(id) DESC\",
page=>1,
rows=>(shift||10) });
}

Finding
related
tags

sub related : ResultSet {
my ($self,$tag)=@_;
return $self->search({
'related.name'=>$tag,
'me.name',{-not_in => [@banned_tags ]},
'me.name'=>(ref $tag ? {-not_in,$tag} :
{'!=',$tag}),
},{
select=>[{count =>
'me.name'},'me.name' ],
as=>[qw/tagcount name/],
join=>'related',
group_by=>[qw/me.name/],
order_by=>\"count(me.name) DESC\",
page=>1,rows=>10,
});
}

Tag
Cloud

HTML::TagCloud

0.33 Mon Mar 13 20:26:36 GMT 2006
- add a 'tags' method that extracts most of the
logic from the html method. It also adds support
for setting levels as a parameter to the
constructor. It defaults to the before-hardcoded
24.
(thanks to Marcus Ramberg)
----
<marcus> acme++

sub get_cloud :ResultSet {
my ($self,$c,$limit) = @_;
my $cloud = HTML::TagCloud->new(levels=>5);
my $tags = $self->aggregated($limit||75);
while( my $tag=$tags->next() ) {
$cloud->add(lc($tag->name),$c->uri_for('/
tag',
lc($tag->name)),$tag->get_column
('tagcount'));
}
return $cloud;
}

Caching

Catalyst::Plugin::PageCache

page_cache:
auto_check_user: 1
set_http_headers: 1
expires: 120
no_cache_debug: 1
auto_cache:
- '/top*'
- '/hot*'

Only for
Anon

Not
POST

Just
Works

Profile
Builder

OSX
perl app

Just core
modules

@apps= map { make_short($_) }
grep{ /\\.(?:app|wdgt|prefPane)$/ }
find_apps('/Applications'),
find_apps($ENV{HOME}.\"/Library/
PreferencePanes\"),
find_apps($ENV{HOME}.\"/Library/Widgets\");
my $data='-F apps='.join(' -F apps=',@apps);
my $res=`curl -s $data http://
osx.iusethis.com/profile/send`;
system('open','http://osx.iusethis.com/
profile/view/'.$res.'?match=1');

Last
Trick

iwatchthis
.com

Random
Profile

sub random : Global {
my ($self,$c) = @_;
my $user=$c->model('DB::Person')
->search({},{
rows => 1,
order_by => \"rand()\",
})->next();
$c->res->redirect(
$c->uri_for('/'.$user->login));
}

Another
person

sub random : Global {
my ($self,$c,$feed) = @_;
my $user=$c->model('DB::Person')
->search({
login => {\"-not_in\"=>[$feed]},
},{
rows => 1,
order_by => \"rand()\",
})->next();
$c->res->redirect(
$c->uri_for('/'.$user->login));
}

one with
movies

sub random : Global {
my ($self,$c,$feed) = @_;
my $user=$c->model('DB::Person')
->search({
login => { '!=' => $feed},
},{
rows => 1,
order_by => \"rand()\",
join => [qw/items/],
having=>{'count(items.id)' => {'>',0 }},
group_by => 'me.id'})->next();
$c->res->redirect(
$c->uri_for('/'.$user->login));
}

not my
profile

sub random : Global {
my ($self,$c,$feed) = @_;
my $user=$c->model('DB::Person')
->search({
login => {\"-not_in\"=>[
($c->user_exists() ?
($feed,$c->user->obj->login) :
$feed ];
},{
rows => 1,
order_by => \"rand()\",
join => [qw/items/],
having=>{'count(items.id)' => {'>',0 }},
group_by => 'me.id'})->next();
$c->res->redirect(
$c->uri_for('/'.$user->login));
}

DBIx::Class
It grows
with you

Questions?
marcus@iusethis.com