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. 336 Part II: Developing Intranet Solutions 13 549669 ch10.qxd 4/4/03 9:25 AM Page 336 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. Chapter 10: Intranet Calendar Manager 337 13 549669 ch10.qxd 4/4/03 9:25 AM Page 337 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 338 Part II: Developing Intranet Solutions 13 549669 ch10.qxd 4/4/03 9:25 AM Page 338 ■ 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. Chapter 10: Intranet Calendar Manager 339 13 549669 ch10.qxd 4/4/03 9:25 AM Page 339 ◆ 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()). 340 Part II: Developing Intranet Solutions 13 549669 ch10.qxd 4/4/03 9:25 AM Page 340 . 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 338 Part II: Developing Intranet Solutions 13. 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. 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