Tạo mạng xã hội với PHP - part 22 pdf

Comments, likes, and dislikes The functionality behind adding comments, likes, and dislikes is very similar to the work we did in Chapter 5 in developing the statuses on a user's profile

'stream-' $data['ID'], 'stream/types/'

$data['type_reference'] '-fromself.tpl.php', $datatags );

}

elseif( $data['poster'] == $data['profile'] )

{

$this->registry->getObject('template')->addTemplateBit(

'stream-' $data['ID'], 'stream/types/'

$data['type_reference'] '-user.tpl.php', $datatags );

}

else

{

// network updates

$this->registry->getObject('template')->addTemplateBit(

'stream-' $data['ID'], 'stream/types/'

$data['type_reference'] '.tpl.php', $datatags );

}

}

}

else

{

If there were no updates, we display the none template

$this->registry->getObject('template')->buildFromTemplates(

'header.tpl.php', 'stream/none.tpl.php', 'footer.tpl.php');

}

}

So, if we had our templates in place at this stage, bringing all of this together,

adding the controller to our database, and viewing /stream what would we see?

This is the basics of our status stream We can now look at adding comments, likes,

and dislikes to the stream

Comments, likes, and dislikes

The functionality behind adding comments, likes, and dislikes is very similar to the

work we did in Chapter 5 in developing the statuses on a user's profile

The concept to adding these to the stream is fairly straightforward Firstly, we

create an empty array of comments / likes / dislikes for each status This way,

if a post has no comments, likes, or dislikes, then by caching the empty array and

sending it to the template, we don't see a blank list where comments should be

If there are comments, they are added to the empty array (making it non-empty),

cached, and sent to the template

Although the method is the same for the three aspects, comments require one

database query, whereas likes and dislikes combined require another, so let's

add in support one at a time

Comments

Take the status IDs we retrieved earlier, and create empty arrays for each of them

$status_ids = implode( ',', $IDs );

$start = array();

foreach( $IDs as $id )

{

$start[ $id ] = array();

}

Copy our new array of empty arrays to be used for comments

// comments

$comments = $start;

Query the database for comments

$sql = "SELECT p.name as commenter, c.profile_post, c.comment FROM

profile p, comments c WHERE p.user_id=c.creator AND c.approved=1

AND c.profile_post IN ({$status_ids})";

$this->registry->getObject('db')->executeQuery( $sql );

if( $this->registry->getObject('db')->numRows() > 0 )

{

If there are comments, iterate through them and add them to the appropriate bucket

(or array) for the status it relates to

while( $comment = $this->registry->getObject('db')->getRows() )

{

$comments[ $comment['profile_post'] ][] = $comment;

}

}

For each of the comments arrays, we cache the data and send them to the

template engine

foreach( $comments as $status => $comments )

{

$cache = $this->registry->getObject('db')->cacheData( $comments );

$this->registry->getObject('template')->getPage()->addTag(

'comments-' $status, array( 'DATA', $cache ) );

}

Likes and dislikes

Likes and dislikes are stored in the same table So we query it, and depending

on the result, put the result in a different array

$likes = $start;

$dislikes = $start;

$sql = "SELECT i.status, p.name as iker, i.iker as iker_id, i.type as

type FROM profile p, ikes i WHERE p.user_id=i.iker AND i.status IN

({$status_ids}) ";

$this->registry->getObject('db')->executeQuery( $sql );

if( $this->registry->getObject('db')->numRows() > 0 )

{

while( $ike = $this->registry->getObject('db')->getRows() )

{

if( $ike['type'] == 'likes' )

{

$likes[ $ike['status'] ][] = $ike;

}

else

{

$dislikes[ $ike['status'] ][] = $ike;

}

}

}

foreach( $likes as $status => $likeslist )

{

$cache = $this->registry->getObject('db')->cacheData( $likeslist );

$this->registry->getObject('template')->getPage()->addTag( 'likes-'

$status, array( 'DATA', $cache ) );

}

foreach( $dislikes as $status => $dislikeslist )

{

$cache = $this->registry->getObject('db')->cacheData(

$dislikeslist );

$this->registry->getObject('template')->getPage()->addTag(

'dislikes-' $status, array( 'DATA', $cache ) );

}

Views

Now we need our template files to provide us with the view

Main template

The main template contains an outer template loop, which is populated based on

the cached status IDs Once this is populated, we have a unique template tag for

each status, ready for the status template to be inserted It also generates three

inner loops—one for comments, one for likes, and one for dislikes

<div id="main">

<div id="rightside">

</div>

<div id="content">

<h1>Updates in your network</h1>

<! START stream >

{stream-{status_id}}

<! START comments-{status_id} >

<p>&nbsp;{comment} by {commenter}</p>

<! END comments-{status_id} >

<! START likes-{status_id} >

<p>{iker} likes this</p>

<! END likes-{status_id} >

<! START dislikes-{status_id} >

<p>{iker} dislikes this</p>

<! END dislikes-{status_id} >

<! END stream >

</div>

Status type templates

For each status type (we have only one at the moment) we need a template for each

context (user's own status, user posting on someone else's profile, someone posting

on a user's profile, and two users in a contact's network posting on their profile)

These templates are stored in the views/default/templates/stream/types folder

Below is the template used when showing the status the logged-in user posted on the

profile of another user:

<p>You posted on {statusprofile_name}'s profile: {statusupdate}</p>

<p class="postedtime">Posted {statusfriendly_time}</p>

In action

Now that we have the model, controller, and views in place, all that leaves us

to do is create a controller record in the database for stream, and visit /stream

as a logged-in user

Room for improvement

We have developed a powerful status stream in this chapter, but as with anything

there is always room for improvement Let's discuss how this might be improved

and extended

Firstly, there is some overlap in terms of logic and queries with the user's profile

and the status' delegator within the profile It may be possible for us to centralize

this functionality and use it in both these instances, perhaps generating a stream

for a profile or generating a stream for a network, depending on methods called

in the object

Secondly, we are doing a few small queries in the controller This is generally best

avoided, and instead models should be used to generate the comments, likes, and

dislikes We could create models for these, which this and the user's profile could

make use of

Plural names are currently hardcoded within the templates So if Bill posts on Ben's

profile, the text is generated by adding 's to the user's name Some names may only

require an apostrophe, so we could look at making this more dynamic

The final obvious area for improvement is the data it pulls in; it currently pulls in

the 20 most recent updates, taking an offset into account We may wish to detect

more recent updates since then, so a user could load in (perhaps through AJAX)

more recent status updates that have occurred while they have been viewing the

stream page

A system stream for administrators

While not as straightforward, as these events won't be centrally stored, we could

also create a stream of system events for the administrator These could include:

• Logins / logouts / signups

• Statuses

• Relationship formations

• When passwords are sent

• When e-mails are sent via the site, and so on

This isn't an essential feature, but could be a nice feature to have depending on

the size of the network and the size of the administrative team running the site

In this chapter we have taken the statuses that users were able to update and post

thanks to our work in Chapter 5 and created a stream of these statuses that the user

can see, based on the activity and contacts within their network on Dino Space

This includes:

• Status updates

• Posting on other user's profiles

• Comments relating to these updates

• Likes / dislikes related to these updates

We've also looked at potential ways to improve and enhance this feature, as well

as what we might wish to consider adding for administrators to see an overview

of the system

With all of this now in place, let's move on to supporting new types of media on

the site, with images, videos, and links being posted onto the profiles of our users!

Public and Private Messages

On Dino Space, we have a new status stream for our users to display the activity

happening in their network One of the things included in the stream was postings

on other users' wall posts, something which our database supports, but at the

moment, our site doesn't!

In this chapter, you will learn:

• How to allow users to post messages on each other's profiles

• How to allow users to post private messages to each other

Most social networking sites support two types of messages: public and private

messages Private messages are generally sent in a similar fashion to e-mails, and

public messages being posted on user's profiles for other users to see

Let's get started with extending our profiles and the status stream!

Public messages

Our status stream from Chapter 6 fully supports public messages and streaming

them to the Dino Space members What we don't yet have, however, is support

for users to post messages on the profiles of other users, so, let's add that in now

Controller

A user should only be able to post a message on another user's profile if they

are connected The post message form should only be displayed if the users are

connected Similarly, a public message post should only be processed if the two

users are connected The controller also needs to display messages that have

been posted on a user's profile too

Displaying profile messages

If we look at our Profilestatusescontroller (controllers/profile/

profilestatusescontroller.php), in the listRecentStatuses method,

we have our query for listing recent profile statuses:

$sql = "SELECT t.type_reference, t.type_name, s.*, p.name as

poster_name FROM statuses s, status_types t, profile p

WHERE t.ID=s.type AND p.user_id=s.poster AND p.user_id={$user}

ORDER BY s.ID DESC LIMIT 20";

At the moment, this query pulls in any posts on a user's profile by the user whose

profile it is If that user has made a post on someone else's profile, the message

instead shows on the user's own profile, which we don't want

We need to change this to pull in the profiles table twice, once for the user who

made the post, and again for the user whose profile is being viewed We will also

want to only pull in posts made on the user's profile, and not posts made by the user

on another user's profile (though this is something we can expand on in the future,

perhaps to indicate that a user has made a post on the profile of another user)

The following query should meet our requirements nicely:

$sql = "SELECT t.type_reference, t.type_name, s.*, pa.name as

poster_name FROM statuses s, status_types t, profile p,

profile pa WHERE t.ID=s.type AND p.user_id=s.profile

AND pa.user_id=s.poster AND p.user_id={$user}

ORDER BY s.ID DESC LIMIT 20";

Now, if we view a user's profile, we see their own status updates, and messages

posted on their profile by other users, as shown in the following screenshot:

Displaying the post message box

The listRecentStatuses method we were just editing is the method we need to

edit to display the post message box This box should only be displayed if the user is

logged in, and is connected to the user If the user is viewing their own profile, then

they should see a box to update their own status:

// post status / public message box

if( $this->registry->getObject('authenticate')->isLoggedIn() == true )

{

$loggedInUser = $this->registry->getObject('authenticate')-

>getUser()->getUserID();

If the logged in user is viewing their own profile, then we add the update template

to the view, so they can update their status:

if( $loggedInUser == $user )

{

$this->registry->getObject('template')->addTemplateBit( 'status_

update', 'profile/statuses/update.tpl.php' );

}

else

{

If the user isn't viewing their own profile, but is logged in, we get any connections

the user has:

require_once( FRAMEWORK_PATH 'models/relationships.php' );

$relationships = new Relationships( $this->registry );

$connections = $relationships->getNetwork( $user, false );

if( in_array( $loggedInUser, $connections ) )

{

If the user is connected to the user whose profile they are viewing, then we allow

them to post a message on the users profile with the post template:

$this->registry->getObject('template')->addTemplateBit(

'status_update', 'profile/statuses/post.tpl.php' );

}

else

{