Tạo mạng xã hội với PHP - part 25 pdf

Public and Private Messages
[ 222 ]
<tr>
<th>Sent</th>
<td>{inbox_sentFriendlyTime}</td>
</tr>
<tr>
<th>Message</th>
<td>{inbox_message}</td>
</tr>
</table>
</div>
</div>
Mark as read
Once a user has read a message, we should update the database to indicate that the
message has been read, so that the user can see at a glance which of their messages
are new and unread, and which ones have already been read. However, for privacy
reasons, we shouldn't show this information to the sender of the message.
To do this, we simply set the read property on the model to 1, and save the record,
as illustrated by the changes to
viewMessage highlighted below:
/**
* View a message
* @param int $message the ID of the message
* @return void
*/
private function viewMessage( $message )
{
require_once( FRAMEWORK_PATH . 'models/message.php' );
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246

Download from www.eBookTM.com
Chapter 7
[ 223 ]
$message = new Message( $this->registry, $message );
if( $message->getRecipient() == $this->registry-
>getObject('authenticate')->getUser()->getUserID() )
{
$this->registry->getObject('template')-
>buildFromTemplates('header.tpl.php', 'messages/view.tpl.php',
'footer.tpl.php');
$message->toTags( 'inbox_' );
$message->setRead(1);
$message->save();
}
else
{
$this->registry->errorPage( 'Access denied',
'Sorry, you are not allowed to view that message');
}
}
Now once the user reads a message, the database records the message as having
been read.
Deleting a message
To delete a message, we simply call the model's delete method, provided the
message was sent to the logged in user of course!
What about the sender?
These deletes will remove the message completely, even from the
sender, but what if we want to have the sender keep their copy, or
have the sender be able to delete their copy? Feel free to extend this
to have an additional eld to indicate whether the message has been

deleted by the sender, and add the functionality in.
/**
* Delete a message
* @param int $message the message ID
* @return void
*/
private function deleteMessage( $message )
{
require_once( FRAMEWORK_PATH . 'models/message.php' );
$message = new Message( $this->registry, $message );
if( $message->getRecipient() == $this->registry-
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
Public and Private Messages
[ 224 ]
>getObject('authenticate')->getUser()->getUserID() )
{
if( $message->delete() )
{
$url = $this->registry->getObject('url')->buildURL( array(),
'messages', false );
$this->registry->redirectUser( $url, 'Message deleted',
'The message has been removed from your inbox');
}
If the message wasn't sent to the logged in user, or if there was a problem deleting
the message, we should display an appropriate error message to the user:
else
{
$this->registry->errorPage( 'Sorry ', 'An error occured

while trying to delete the message');
}
}
else
{
$this->registry->errorPage( 'Access denied',
'Sorry, you are not allowed to delete that message');
}
}
Composing a new message
Composing a new message is the most complicated aspect for the feature, as there
are a number of aspects to consider (and change, depending on the needs of the
social network). Let's discuss these as we walk through the code:
/**
* Compose a new message, and process new message submissions
* @parm int $reply message ID this message is in reply to [optional]
only used to pre-populate subject and recipient
* @return void
*/
private function newMessage( $reply=0 )
{
$this->registry->getObject('template')->buildFromTemplates('header.
tpl.php', 'messages/create.tpl.php', 'footer.tpl.php');
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
Chapter 7
[ 225 ]
The two strands of this feature (displaying the new message form, and processing
the new message) require knowing a list of members that the message can be sent to

(provided we wish to restrict sending to contacts only). As this is the case, it makes
sense for us to require the relationships model, and instantiate it before progressing:
require_once( FRAMEWORK_PATH . 'models/relationships.php' );
$relationships = new Relationships( $this->registry );

if( isset( $_POST ) && count( $_POST ) > 0 )
{
If the user has submitted a new message, we need to check that the recipient
they have selected is in their network (that is, that they are allowed to send
them a message):
$network = $relationships->getNetwork( $this->registry-
>getObject('authenticate')->getUser()->getUserID() );
$recipient = intval( $_POST['recipient'] );
if( in_array( $recipient, $network ) )
{
If the recipient is in the user's network, then we create an instance of the message
model, populate it with the data the user has submitted, and then save the message
and redirect the user after displaying a conrmation message:
// this additional check may not be something we require for
private messages?
require_once( FRAMEWORK_PATH . 'models/message.php' );
$message = new Message( $this->registry, 0 );
$message->setSender( $this->registry-
>getObject('authenticate')->getUser()->getUserID() );
$message->setRecipient( $recipient );
$message->setSubject( $this->registry->getObject('db')-
>sanitizeData( $_POST['subject'] ) );
$message->setMessage( $this->registry->getObject('db')-
>sanitizeData( $_POST['message'] ) );
$message->save();

// email notification to the recipient perhaps??

// confirm, and redirect
$url = $this->registry->getObject('url')->buildURL( array(),
'messages', false );
$this->registry->redirectUser( $url, 'Message sent', 'The
message has been sent');
}
else
{
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
Public and Private Messages
[ 226 ]
If the recipient isn't in their network, we display an error page. Alternatively, we
could check the recipient's privacy settings to see if they allow messages from any
user—something to consider when implementing privacy controls:
$this->registry->errorPage('Invalid recipient',
'Sorry, you can only send messages to your recipients');
}
}
else
{
If the user hasn't submitted the form, then we need to display the new message form
to them. We can get the list of potential recipients (to go in a drop down) from the
relationships model, which we associate with a template variable.
$cache = $relationships->getByUser( $this->registry-
>getObject('authenticate')->getUser()->getUserID() );
$this->registry->getObject('template')->getPage()-

>addTag( 'recipients', array( 'SQL', $cache ) );
if( $reply > 0 )
{
If the message is in reply to another message, then we can provide some basic
support for this, such as pre-selecting the recipient, and pre-completing the
subject line based off the message this is in reply to:
require_once( FRAMEWORK_PATH . 'models/message.php' );
$message = new Message( $this->registry, $reply );
if( $message->getRecipient() == $this->registry-
>getObject('authenticate')->getUser()->getUserID() )
{
$this->registry->getObject('template')-> getPage()-
>addAdditionalParsingData( 'recipients', 'ID',
$message->getSender(), 'opt', "selected='selected'");
$this->registry->getObject('template')->getPage()-
>addTag( 'subject', 'Re: ' . $message->getSubject() );
}
else
{
$this->registry->getObject('template')->getPage()-
>addTag( 'subject', '' );
}

This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
Chapter 7
[ 227 ]
}
else

{
$this->registry->getObject('template')->getPage()-
>addTag( 'subject', '' );
}
}

}
Creating a message template
For the new message template (views/default/templates/messages/create.
tpl.php)
, we have a template loop for possible recipients. If the message is a reply,
the recipient is selected via the additionalParsingData set in the controller. The
subject is also pre-populated for us:
<div id="main">
<div id="rightside">

<ul>
<li><a href="messages/">Your inbox</a></a>
</ul>
</div>

<div id="content">
<h1>Compose message</h1>
<form action="messages/create" method="post">
<label for="recipient">To:</label><br />
<select id="recipient" name="recipient">
<! START recipients >
<option value="{ID}" {opt}>{users_name}</option>
<! END recipients >
</select><br />

<label for="subject">Subject:</label><br />
<input type="text" id="subject" name="subject"
value="{subject}" /><br />
<label for="message">Message:</label><br />
<textarea id="message" name="message"></textarea><br />

This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
Public and Private Messages
[ 228 ]
<input type="submit" id="create" name="create" value="Send
message" />
</form>

</div>
</div>
In action
If we visit our message centre /messages, we can see our inbox (once the controller
is added to the controllers table in the database!), as shown in the screenshots earlier
in the chapter.
If we click reply, we are taken to the same screen as with creating a new message,
except the recipient is pre-selected and the subject is the subject of the previous
message prexed with Re:.
Room for improvement?
There are three particular areas that can be improved signicantly:
• Sent items
• Replies
• Group messages
Sent items

At the moment, we can't see sent items, and while in principle this could be added
easily, the problem lies if a user deletes the message. We would need to add two
columns to the database, one indicating that the recipient has deleted it from their
inbox, and one indicating the sender has deleted it from their sent items, as we
discussed earlier in the chapter.
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
Chapter 7
[ 229 ]
Replies
Our replies are not linked together; they are all stored as standalone messages,
which is something we could improve.
Group messages
At the moment, private messages are only between two users, but we may wish
to extend this in the future to support any number of users.
Summary
In this chapter, we have taken extended statuses on our users' proles to support
public messages between users. These public messages can use the comments system
we have in place to form public conversations. We have also created a private
messages area that allows users to communicate with one another in private.
Next, we can look at further extending the statuses system to support more types
of message.
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com
Statuses—Other Media

With our status stream now supporting simple-text updates from the prole owner,
and public messages from other users, it is time for us to integrate other types of
media into these statuses.
In this chapter, you will learn how to integrate other types of media in prole
posts, including:
• Images
• Videos
• Links
The core information to our current statuses is held within the statuses table. We will
keep this the same. However, depending on the type of status update, we may call
upon other database tables to extend the information available to us.
Since different status types will use different status tables, we should use a left join
to connect the tables, so we can keep just a single query to look up the statuses.
It also pulls in the extra information when it is required.
Let's get started with extending our proles and the status stream!
Why support other media types?
The following are the potential uses of supporting other media types for Dino
Space users:
• Sharing videos of their pet dinosaurs
• Sharing photographs with other users
• Sharing relevant links with their contacts
This material is copyright and is licensed for the sole use by RAYMOND ERAZO on 25th October 2010
3146 KERNAN LAKE CIRCLE, JACKSONVILLE, 32246
Download from www.eBookTM.com