Secure PHP Development- P74 ppsx

◆
Sharing and assigning events among users: Users can create events for
themselves or assign events to others or even share events with multiple
users.
◆
Automatic reminders: Users can choose to be reminded about an event
when they log in to the intranet on the day of the event.
Let’s look at the prerequisites of the calendar system.
Understanding Prerequisites
The event calendar builds on the intranet classes discussed in the Chapters 4
through 7. For example, it uses the Message class (discussed in Chapter 7) to
announce event reminders. That class enables the application to create and delete
messages.
The intranet calendar applications that you’ll develop require the central
login/logout, user management, and intranet home applications discussed in those
earlier chapters.
Now let’s look at the database design and implementation needed for creating
the intranet calendar manager.
Designing the Database
Figure 10-1 shows the database diagram for the intranet calendar manager. Here
the CALENDAR_EVENT table holds the event data, CALENDAR_EVENT_VIEWER
table holds the viewer list for an event in the CALENDAR_EVENT table. The
CALENDAR_REPETITIVE_EVENTS table stores information about how an event is
repeated.
Figure 10-1: Intranet calendar manager database diagram.
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Table 10-1 provides the details of the database tables.
TABLE 10-1 CALENDAR DATABASE TABLES
Table Description
CALENDAR_EVENT This table is the integral part of this database. It holds

the event number (
EVENT_ID), user ID (USER_ID),
event title (
EVENT_TITLE), event date
(
EVENT_DATE), event description (EVENT_DESC),
reminder ID (
REMINDER_ID), and a check flag (FLAG).
The event number (
EVENT_ID) is automatically
generated by the database.
CALENDAR_EVENT_VIEWER Holds the calendar event viewer information. The
calendar event viewer consists of the
EVENT_ID and
VIEWER_ID.
CALENDAR_REPETITIVE_EVENTS Holds the calendar repetitive event information. The
calendar repetitive event consists of
EVENT_ID and
repeat mode (REPEAT_MODE).
The ch10/sql/calendar.sql file in the CDROM contains all the table creation
statements for the CALENDAR database. You can create this CALENDAR database
in your MySQL server by running the following commands.
mysqladmin -u root -p create CALENDAR
mysql -u root -p -D CALENDAR < calendar.sql
Make sure you change the user name (root) to whatever is appropriate for your
system.
With the intranet calendar manager database established, it’s time to look at the
PHP classes that are needed to implement the applications.
The Intranet Calendar Application
Event Class

We need only one new object, the Event object, to implement the intranet calendar
manager, as you can see in Figure 10-2, which shows the system diagram. The
Message object was discussed in Chapter 7.
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Figure 10-2: Intranet calendar manager system diagram.
The Event class provides the Event object. The class is used to manipulate each
event. It allows an application to create and delete events. The ch10/apps/class/
class.Event.php in the CDROM is an implementation of this class.
This class implements the following methods:
◆
Event (): This is the constructor method. It performs the following
functions:
■
Sets an object variable named dbi to point to the class.DBI.php-
provided object, which is passed to the constructor by an application.
dbi holds the DBI object that is used to communicate with the back-
end database.
■
Sets a member variable named event_tbl to $CALENDAR_EVENT_TBL,
which is loaded from the calendar.conf file. $CALENDAR_EVENT_TBL
holds the name of the calendar event table.
■
Sets a member variable named event_view_tbl to $CALENDAR_EVENT_
VIEW_TBL
, which is loaded from the calendar.conf file. $CALENDAR_
EVENT_VIEW_TBL
holds the name of the event view table.
■
Sets a member variable named event_repeat_tbl to $CALENDAR_

EVENT_REPEAT_TBL
, which is loaded from the calendar.conf file.
$CALENDAR_EVENT_REPEAT_TBL holds the name of the event repeat
table.
■
Sets a member variable called ‘std_fields’ as an associative array to
hold the attributes of the calendar event table and their data types
(text/number).
Central
Login/Logout
Messages
Calendar Events
User Home Interface
PHP Application Framework
Message Object
Intranet Calendar Applications
Event Object
class.Message.php
class.Events.php
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■
Sets a member variable named ‘fields’, which is a comma-separated
list of calendar event table fields.
■
Calls setEventID() to set the given event ID to this object.
◆
loadEventInfo (): This method sets all the attribute values for a given
event as member variables to this class. This is how it works:
■

The given event ID is set to a member variable called to eid using
setEventID().
■
A statement to select all the event table fields for the given event ID is
created in $stmt.
■
Using the DBI object $this->dbi, the $stmt statement is run via the
$this->dbi->query() method in DBI object. The result of the query is
stored in the $result variable.
■
If there are more than zero rows in the $result object, each row is
fetched in the $row variable.
■
For each message field of type text, the data is stripped for embedded
slash characters.
■
Each message field data is stored as object variable using $this-
>$fieldname
run-time variable.
◆
getEvents (): This method returns all the events that are to be shown to
the given user on a given date. It works as follows:
■
The date string (mm-dd-yyyy format) passed to this method is used to
find out these three formats of the given date: the day of the week
string, the day of the month string, and the month-day string. These
formats are later used to check whether the given date is a weekly,
monthly, or yearly repetitive date.
■
A statement to select all the events that are to be viewed by the given

user on the given date is prepared. This statement also selects the events
viewable by the given user that fall on this day because of the repetitive
event feature. The statement is stored in a variable named $stmt.
■
Using the DBI object ($this->dbi), the $stmt statement is run via the
$this->dbi->query() method in the DBI object. The result of the
query is stored in the $result variable.
■
If there are more than zero rows in the $result object, each row is
fetched in the $row variable.
■
An associative array is prepared using each row’s event ID and Event
Title.
■
The method returns the array. If the result set is found to be empty, the
method returns null.
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◆
getOwnEvents (): This method returns the events that are created by the
given user for a given day. This is how it works:
■
The date string parameter is formatted using addslashes and the
quote() method of the DBI object.
■
A statement to select all the events that are created by this user for the
given date is prepared and stored in $stmt.
■
Using the DBI object $this->dbi, the $stmt statement is run via the
$this->dbi->query() method in the DBI object. The result of the

query is stored in the $result variable.
■
If there are more than zero rows in the $result object, each row is
fetched in the $row variable.
■
An associative array is prepared using each row’s event ID and event title.
■
The method returns the array. If the result set is empty, the method
returns null.
◆
getViewers (): This method returns all viewer IDs for a given event. This
is how it works:
■
It sets the event ID using setEventID().
■
A statement to select all the viewer IDs (user ID) of the event viewer
table for the given event ID is prepared and stored in $stmt.
■
Using the DBI object ($this->dbi), the $stmt statement is run via the
$this->dbi->query() method in the DBI object. The result of the
query is stored in the $result variable.
■
If there are more than zero rows in the $result object, each row is
fetched in the $row variable.
■
An associative array is prepared using each row’s event ID and event title.
■
The method returns the array. In case the result set found is empty, the
method returns null.
◆

addEvent (): This method adds a new event into to the CALENDAR_EVENT
table. Attributes such as user ID, event title, event date, event description,
reminder ID, and flag are passed as an associative array to this method. It
works as follows:
■
From the given parameter, all the values of text type in the database
are escaped for characters such as quotation marks and slashes using
$this->dbi->quote(addslashes()).
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